I finally got a chance to tow some weight with my LLY this weekend. Up until now, it hasn't given any indication of overheating....some fan noise, but that's been it. Most of our towing is under 9k, but we've got a pretty serious climb to get home.

Anyway, here's the details:
14k trailer
85-90 degree OAT
4 miles at an average grade of 5% at 50mph
2 miles of 20-30mph at an average grade of 12.5% (this part has a very steep section with >15% grade)

Motor got up to 235 on the stock guage (I know, it probably much higher). Fan came on shortly after starting the steeper hill and stayed on the rest of the way. The guage hit this temp at about 1 mile and stayed there the rest of the way until I stopped, at which time it quickly returned to normal. BTW, Ally temps were around 220 running in 1st-2nd gear.

I just wanted to share this experience, thought some might find it usefull.:blahblah:

The hills are the killer, especially in July and August (hot outside temperatures) to these load pulling LLYs. Some drivers think they do not have an OverHeating LLY, but they are in fantasy land or just havn't had to work their truck yet. If you want your truck to last, you have to stop the OH of the Duramax!

I finally got a chance to tow some weight with my LLY this weekend. Up until now, it hasn't given any indication of overheating....some fan noise, but that's been it. Most of our towing is under 9k, but we've got a pretty serious climb to get home.

Anyway, here's the details:
14k trailer
85-90 degree OAT
4 miles at an average grade of 5% at 50mph
2 miles of 20-30mph at an average grade of 12.5% (this part has a very steep section with >15% grade)

Motor got up to 235 on the stock guage (I know, it probably much higher). Fan came on shortly after starting the steeper hill and stayed on the rest of the way. The guage hit this temp at about 1 mile and stayed there the rest of the way until I stopped, at which time it quickly returned to normal. BTW, Ally temps were around 220 running in 1st-2nd gear.

I just wanted to share this experience, thought some might find it usefull.:blahblah:
where did you find a 15% grade?most highway standards dont allow anything more than 9% for a mile or less.

where did you find a 15% grade?most highway standards dont allow anything more than 9% for a mile or less.

It's an old county road that leads to my house. Most of it is 10%, but there is a stretch that's a fair bit steeper.....And before anyone calls bs, I'm a surveyor, so I do know something about grades):h

The hills are the killer, especially in July and August (hot outside temperatures) to these load pulling LLYs. Some drivers think they do not have an OverHeating LLY, but they are in fantasy land or just havn't had to work their truck yet. If you want your truck to last, you have to stop the OH of the Duramax!

doesnt look like his is overheating.

doesnt look like his is overheating.


What??:confused:

this is not considered overheating everyone, lets not mistake what that actually is. His truck got hot,yes, but did NOT overheat. His alarms/warnings did not go off which means temps never reached 250, he didn't lose coolant all over the place and truck did not shut down. he is merely stating what he did to get the temps that he got.

not starting a beef here, but if you read the tons of OH threads with trucks that ARE overheating you will know it.

this is not considered overheating everyone, lets not mistake what that actually is. His truck got hot,yes, but did NOT overheat. His alarms/warnings did not go off which means temps never reached 250, he didn't lose coolant all over the place and truck did not shut down. he is merely stating what he did to get the temps that he got.

not starting a beef here, but if you read the tons of OH threads with trucks that ARE overheating you will know it.

In my book, 235 ( even if you believe the gauge for what it says: which I know is false) IS OVERHEATING. I have puked coolant in the stock configuration, and the 235 reading is right next to the line of puking. Now days anything over 210 is OVERHEATING in my book!
:cool2:

Thanks for the post. One of the more informative one at the DP. As always with a group discussion there is always a definition problem.

Now days anything over 210 is OVERHEATING in my book!
:cool2:

for a gasser. my truck runs 210 empty

this is not considered overheating everyone, lets not mistake what that actually is. His truck got hot,yes, but did NOT overheat. His alarms/warnings did not go off which means temps never reached 250, he didn't lose coolant all over the place and truck did not shut down. he is merely stating what he did to get the temps that he got.

not starting a beef here, but if you read the tons of OH threads with trucks that ARE overheating you will know it.

I can tell you work for GM cause thats the exact same propaganda they feed me at the dealer and on the phone. Deny deny deny deny!

I agree with you, it is what it is, and what it is for real is he got lucky that the temp was mild for this summer at 85-90 degrees. Try it again at 95-100 degrees, there is a world of difference. I always thought my truck was not an "overheater" until I tried pulling 14k and 13 feet tall up a long grade on a 97-98 degree day. He didn't say what the load was behind him either. Maybe low drag, but for sure the temperature was low.

All of you guys that have never actually pulled a high drag (as in 13 foot tall by 8 foot wide) heavy load (14k-15k) in high heat (95-100 degrees) up a long grade (5+ miles) that causes you to stay floored or above 90% throttle for 5 to 6 minutes or more are not helping things by telling everyone that all LLY trucks do not overheat. You have to have all of these coditions to get the wake up call. ALL OF THEM.

Am I bitter? YES, I sure am. I should be after getting ripped for $47,000 by GM and then have guys that have never towed a real load in real heat for extended periods tell me that they dont overheat. BS! Go try it! Otherwise be quiet about what you have no clue of!

Before a bunch of people jump me, make sure you have met ALL of the above conditions at the same time because if you have not then to be honest (sorry!) you just dont know what you are talking about!

FACT: ALL LLY TRUCKS ARE OVERHEATERS, THE ONES THAT SAY THEY ARE NOT HAVE NOT KEPT THE TRUCK WORKING HARD LONG ENOUGH.


:rant:

The purpose of my post was not to say whether or not I overheated, but to share my experience for the day for others to be able to have something to compare to since I never see anything about low speed towing up steep grades. Most other stories are of people pulling max weight in the worst conditions at high speeds. I simply wanted to give some data in a different environment. Also, it was not my intent to spark a riot.

That being said, I'll try to add additional information as needed. This particular load was some hay on a dual-axle gooseneck flatbed. It was stacked just over the top of the cab, so I don't know how much drag it really had. At the low speeds that I was going, drag is probably negligible anyways. This particular climb took probably 5-8 minutes and I would say that 60% of that is spent at WOT or close to it.....guessing here.

Mods.....if this turns into another pissing contest, please do everyone a favor and delete the thread.

I can tell you work for GM cause thats the exact same propaganda they feed me at the dealer and on the phone. Deny deny deny deny!

I agree with you, it is what it is, and what it is for real is he got lucky that the temp was mild for this summer at 85-90 degrees. Try it again at 95-100 degrees, there is a world of difference. I always thought my truck was not an "overheater" until I tried pulling 14k and 13 feet tall up a long grade on a 97-98 degree day. He didn't say what the load was behind him either. Maybe low drag, but for sure the temperature was low.

All of you guys that have never actually pulled a high drag (as in 13 foot tall by 8 foot wide) heavy load (14k-15k) in high heat (95-100 degrees) up a long grade (5+ miles) that causes you to stay floored or above 90% throttle for 5 to 6 minutes or more are not helping things by telling everyone that all LLY trucks do not overheat. You have to have all of these coditions to get the wake up call. ALL OF THEM.

Am I bitter? YES, I sure am. I should be after getting ripped for $47,000 by GM and then have guys that have never towed a real load in real heat for extended periods tell me that they dont overheat. BS! Go try it! Otherwise be quiet about what you have no clue of!

Before a bunch of people jump me, make sure you have met ALL of the above conditions at the same time because if you have not then to be honest (sorry!) you just dont know what you are talking about!

FACT: ALL LLY TRUCKS ARE OVERHEATERS, THE ONES THAT SAY THEY ARE NOT HAVE NOT KEPT THE TRUCK WORKING HARD LONG ENOUGH.


:rant:I don't mean to pi$$ off anyone, but you may want to be careful about making blanket statements that could come back to bite you.:rolleyes:

First of all ALL LLY trucks are NOT overheaters. I have not read of single instance to date that indicates that the 2006 LLY's have an overheating problem. I suspect that your claim "could" be made when talking about most 2004.5 thru 2005 LLY's, but not the 2006 LLY.

Also, pulling a 14K - 15K trailer "could" be heavier than GM recommends for a 2500HD, especially if it is a bumper pull trailer. So in that case GM could easily say that you are S.O.L. if pulling that heavy of a load.

Below is a page out of the GM Owners Manual with recommended trailer loads.

I agree that there is no excuse for any truck to be overheating when towing a load that they have been advertised to be able to pull, but making blanket statements like those above "could" hurt one's credibility when trying to get the truck fixed if not careful.

First of all ALL LLY trucks are NOT overheaters:blahblah: .

Also, pulling a 14K - 15K trailer "could" be heavier than GM recommends for a 2500HD, especially if it is a bumper pull trailer. So in that case GM could easily say that you are S.O.L. if pulling that heavy of a load.



Anyways, my truck, by the manual should be able to handle 12,000 lbs. on the bumper.:rolleyes: Put a 6,000 lb. load on mine and my fan will whistle "dixie."

I finally got a chance to tow some weight with my LLY this weekend. Up until now, it hasn't given any indication of overheating....some fan noise, but that's been it. Most of our towing is under 9k, but we've got a pretty serious climb to get home.

Anyway, here's the details:
14k trailer
85-90 degree OAT
4 miles at an average grade of 5% at 50mph
2 miles of 20-30mph at an average grade of 12.5% (this part has a very steep section with >15% grade)

Motor got up to 235 on the stock guage (I know, it probably much higher). Fan came on shortly after starting the steeper hill and stayed on the rest of the way. The guage hit this temp at about 1 mile and stayed there the rest of the way until I stopped, at which time it quickly returned to normal. BTW, Ally temps were around 220 running in 1st-2nd gear.

I just wanted to share this experience, thought some might find it usefull.:blahblah:

Thanx for the post, good "FYI" info. :) I hope you will post again when you have another radical tow experience. ;)

I can tell you work for GM cause thats the exact same propaganda they feed me at the dealer and on the phone. Deny deny deny deny!


THIS is exactly what I'm talking about. You've been a member here for how long? 2 weeks?...

The purpose of my post was not to say whether or not I overheated, but to share my experience for the day for others to be able to have something to compare to since I never see anything about low speed towing up steep grades.

Thank You. How many times does this have to be said.... my post gets taken all out of context and now I work for GM too. His truck did NOT overheat...as HE said in the first post; he is sharing his data and how hot it got and hoping it will be helpful to others.

If he decides to tow in higher temps then it may in fact overheat, but it did NOT in this case. That is ALL I'M saying. Just cause your truck hits 211 on the guage doesn't mean it is overheating. READ ALL THE OH THREADS FIRST BEFORE GIVING YOUR OPINION. Many valueable members including mods have done EXTENSIVE research on this and not all LLY's overheat no matter what you say.

Censored
B.

Thanx for the post, good "FYI" info. :) I hope you will post again when you have another radical tow experience. ;)


Radical would be when I towed 19.5k up this same hill in 75 degree weather with my 2002 6.0L gasser:badidea: ....and it did overheat. I had to put it in 4-low and barely made it up the hill:eek:. Trans and engine warnings both went off.

According to this link, the max trailer for my truck is 14200 in gooseneck trim...So in fact, I probably was at max. :rolleyes: or at least close to it.
http://www.gmc.com/sierra/2500HD/specsDimension.jsp

All of you guys that have never actually pulled a high drag (as in 13 foot tall by 8 foot wide) heavy load (14k-15k) in high heat (95-100 degrees) up a long grade (5+ miles) that causes you to stay floored or above 90% throttle for 5 to 6 minutes or more are not helping things by telling everyone that all LLY trucks do not overheat. You have to have all of these coditions to get the wake up call. ALL OF THEM.At no place in this thread did I see anyone say that!

Anyways, my truck, by the manual should be able to handle 12,000 lbs. on the bumper.:rolleyes: Put a 6,000 lb. load on mine and my fan will whistle "dixie."Kep in mind also, that having the fan come on does not mean that the truck is overheating. As long as the coolant temperatures are kept under control by the fan, the cooling system is doing its job.

I agree that the fan is anoying and it does affect fuel economy big time, but it is part of the complete cooling system and is there for a reason; to help control coolant temperatures.

BTW - The overheat alarm is theoretically set to go off at a temperature below the point where immediate engine damage will occur. Continued driving after the alarm temperature has been exceeded, will definitely cause coolant to boil over and can cause subsequent engine damage. I have run engines on dynamometers at 245° - 250° F while running heat rejection tests and as long as there was adequately pressurized (15 psi) coolant (50-50 mixture) flowing though the engine, there was no engine damage.

According to this link, the max trailer for my truck is 14200 in gooseneck trim...So in fact, I probably was at max. :rolleyes: or at least close to it.
http://www.gmc.com/sierra/2500HD/specsDimension.jspYes you are correct. Also, the max. gooseneck/5th-wheel trailer load for a CC/Long-Bed 4WD is 13200 while for a Reg-Cab/Long-Bed 2WD it is 15900. My point was that telling someone to hook up a 14K to 15K trailer could cause them to overload their particular truck and could create problems for them if they were to complain about overheating if in fact their truck was overloaded.

toyotasaurus,

Your post was most welcome and informative.

Thank you for taking your time, Sincerely.

Yes you are correct. Also, the max. gooseneck/5th-wheel trailer load for a CC/Long-Bed 4WD is 13200 while for a Reg-Cab/Long-Bed 2WD it is 15900. My point was that telling someone to hook up a 14K to 15K trailer could cause them to overload their particular truck and could create problems for them if they were to complain about overheating if in fact their truck was overloaded.

There is only one setup that has a max pull under 14k, thats why I used 14k-15k as the example. Lets not nitpick, the cooling systems are the same anyway. It can be done with 13k if it is max height and width, the drag is the added factor. I can pull 14k total of pipe or beams on the goose without anything but some fan action, but put 14k worth of tall and wide RV or Toyhauler back there and add a wind coming at you between 10 and 2 o'clock and thats it. The drag added to the weight is what keeps the workload higher, and brings on the overheat. I have found if you remove any of the factors I named before then I can "get by" in the 220-230 range like the thread starter, but when they are all there....well..... there is no way to maintain speed without getting alarms.

All LLY trucks do this. Every one of them. The ones that say they don't just haven't had all the conditions together, but if they ever do, they will get there eyes opened!

I apologize for getting "hot" but this thing pisses me off. :mad:

I can tell you work for GM cause thats the exact same propaganda they feed me at the dealer and on the phone. Deny deny deny deny!

I agree with you, it is what it is, and what it is for real is he got lucky that the temp was mild for this summer at 85-90 degrees. Try it again at 95-100 degrees, there is a world of difference. I always thought my truck was not an "overheater" until I tried pulling 14k and 13 feet tall up a long grade on a 97-98 degree day. He didn't say what the load was behind him either. Maybe low drag, but for sure the temperature was low.

All of you guys that have never actually pulled a high drag (as in 13 foot tall by 8 foot wide) heavy load (14k-15k) in high heat (95-100 degrees) up a long grade (5+ miles) that causes you to stay floored or above 90% throttle for 5 to 6 minutes or more are not helping things by telling everyone that all LLY trucks do not overheat. You have to have all of these coditions to get the wake up call. ALL OF THEM.

Am I bitter? YES, I sure am. I should be after getting ripped for $47,000 by GM and then have guys that have never towed a real load in real heat for extended periods tell me that they dont overheat. BS! Go try it! Otherwise be quiet about what you have no clue of!

Before a bunch of people jump me, make sure you have met ALL of the above conditions at the same time because if you have not then to be honest (sorry!) you just dont know what you are talking about!

FACT: ALL LLY TRUCKS ARE OVERHEATERS, THE ONES THAT SAY THEY ARE NOT HAVE NOT KEPT THE TRUCK WORKING HARD LONG ENOUGH.


:rant:


Learn to actually comprehend what you're reading, then go back to the original post. It was about the temps he got. No claims were made about overheating or not overheating.

well i understand what the OP is saying, and i apprecitate the info. but i keep reading in this and all the other OH posts about how the non OH just havent "tried" hard enough. this is what i dont understand...........it takes max trailer weight, max amb temp, high alt., max frontal area, steep grade, all for at least 5 minutes to OH??? am i the only one who didnt expect an OH under this worst case situation?

The thermostats arn't fully open & closed till about 230.. untill then the truck is in closed loop mode. after that ~230 the truck is in thermal run-away. Totally dependent on outside factors.. like the throttle dropping.. as in the hill ends, speed slows, wind shifts.. whatever.. if the throttle holds, you are going to overheat..

The thermostats arn't fully open & closed till about 230.. untill then the truck is in closed loop mode. after that ~230 the truck is in thermal run-away. Totally dependent on outside factors.. like the throttle dropping.. as in the hill ends, speed slows, wind shifts.. whatever.. if the throttle holds, you are going to overheat..

:confused:

His temp was at 230 which is hot, and I suspect it would have gotten even hotter if given the chance. AT 230 the cooling system is already overloaded (I dont know why some cant grasp this) The cooling system on the LLY is not capable of rejecting the BTUs created by this engine. Once the system starts to climb in temp. it is a runaway heat wave until one of the factors causing the heat stops, like throttle reduction, load reduction etc.

Wolford...
That's the interesting part of this because it went from 210-230ish pretty quick and held it there while I was mostly WOT for almost a mile at about 20mph. I was fully expecting it to keep going, but it didn't...go figure. None of this stuff is totally predictable.

There is only one setup that has a max pull under 14k, thats why I used 14k-15k as the example. Lets not nitpick, the cooling systems are the same anyway. It can be done with 13k if it is max height and width, the drag is the added factor. I can pull 14k total of pipe or beams on the goose without anything but some fan action, but put 14k worth of tall and wide RV or Toyhauler back there and add a wind coming at you between 10 and 2 o'clock and thats it. The drag added to the weight is what keeps the workload higher, and brings on the overheat. I have found if you remove any of the factors I named before then I can "get by" in the 220-230 range like the thread starter, but when they are all there....well..... there is no way to maintain speed without getting alarms.

All LLY trucks do this. Every one of them. The ones that say they don't just haven't had all the conditions together, but if they ever do, they will get there eyes opened!

I apologize for getting "hot" but this thing pisses me off. :mad:

I can understand your frustration.....but let me play Devil's Advocate here..

....Maybe these trucks were intended to pull an average drag 14k trailer in most conditions. Maybe the engineers didn't account for someone essentially dragging a parachute along with their 14k trailer in 100+ degree temps up a mountain. What would the equivalent weight of a 14k trailer with a high drag be? 18k, 20k.....?......I don't have any idea. Since you agree that the truck will effectively pull 14k of low drag trailer, did it ever occur that maybe 14k with a parachute is a little more than it should handle? I'm not trying to start anything, just playing the other side:)

Now, that being said...I agree that the cooling system is not what it should be. Obviously, from all the testing and reports that I read, it is not capable of shedding all the heat produced by this motor when held at maximum power for long periods of time. My question is...are there many cooling systems capable of this? See my earlier reply about the pull with the gasser I had.
:blahblah::blahblah::blahblah::blahblah:
...and I'm by no means an expert at any of this, so nobody wig out on me.

His temp was at 230 which is hot, and I suspect it would have gotten even hotter if given the chance. AT 230 the cooling system is already overloaded (I dont know why some cant grasp this) The cooling system on the LLY is not capable of rejecting the BTUs created by this engine. Once the system starts to climb in temp. it is a runaway heat wave until one of the factors causing the heat stops, like throttle reduction, load reduction etc.

I'm glad to see that I'm not the only one here that thinks 230 is way to hot. I love my truck as long as I'm not pulling anything in the desert.
My LLy gets a big fat F for a grade when it come to pulling in high temps up long grades.

I can understand your frustration.....but let me play Devil's Advocate here..

....Maybe these trucks were intended to pull an average drag 14k trailer in most conditions. Maybe the engineers didn't account for someone essentially dragging a parachute along with their 14k trailer in 100+ degree temps up a mountain. What would the equivalent weight of a 14k trailer with a high drag be? 18k, 20k.....?......I don't have any idea. Since you agree that the truck will effectively pull 14k of low drag trailer, did it ever occur that maybe 14k with a parachute is a little more than it should handle? I'm not trying to start anything, just playing the other side:)

Now, that being said...I agree that the cooling system is not what it should be. Obviously, from all the testing and reports that I read, it is not capable of shedding all the heat produced by this motor when held at maximum power for long periods of time. My question is...are there many cooling systems capable of this? See my earlier reply about the pull with the gasser I had.
:blahblah::blahblah::blahblah::blahblah:
...and I'm by no means an expert at any of this, so nobody wig out on me.

Leave out the safety part of the weight for a minute and consider some things.

Its not the weight that is the deciding factor. It is the load put on the darned engine. The weight is just the obvious way to create load. It takes power to get a lot of weight rolling, but not a lot to keep it rolling. With the same drag, towing heavy on flat ground it dont take really any more power to keep 15k at 60mph as it does to keep 30k at 60mph. Getting it moving from stopped is harder yes, because you are accelerating the weight and that takes power, but once you are at speed it is the drag that remains on flat ground and the weight dont matter.

Add a hill and then the work to do is doubled. The amount of power needed to keep to 60mph with the 30k is at least twice that of the 15k. Power is heat. If you are then making more heat than you have cooling, its simply a race to see which takes longer, getting to the top of the hill or overheating the truck.

The cooling system of these trucks or any other vehicle should be set to handle what heat the engine makes. This one cant. Thats for sure too because I have won bets with all my buddies and their buddies on this, some of them made their money back on the next guy, my truck and 6 others in a row all failed to make baker with the same trailer. They all got o-heat alarms like clockwork. All of em, 7 in a row. So its all of LLY trucks period, cause 7 people didnt pick 7 trucks at random and be unlucky to pick 7 "overheaters" if it is "only a small percentage" like some say. I am not a statistics guy but them odds are easy to see.

Before anyone gets on me about how we did it, it was 14k and no we didnt do them back to back to back, it was spread out over a few months of talk and bets and crap talking, but the trailer was the same everytime and the road was the same and the temp outside ran from a low of 95 to a high of 102 and they all crapped out the same to many a suprised owner!

Oh well we had plenty of cold beer each time! :lol:

I would bet anyone with a stock 04.5-05 and I mean anyone that they cannot pull 14,000 pounds up baker grade in 100+ degree heat and maintain freeway(60-70mph) speeds. I overheat that grade with 7k let alone 14k. 22+ miles of nothing but climb.:eek:

I would bet anyone with a stock 04.5-05 and I mean anyone that they cannot pull 14,000 pounds up baker grade in 100+ degree heat and maintain freeway(60-70mph) speeds. I overheat that grade with 7k let alone 14k. 22+ miles of nothing but climb.:eek:


60-70mph up baker grade with 14K??? i think im begining to understand the whole "OH problem".

60-70mph up baker grade with 14K??? i think im begining to understand the whole "OH problem".


Well an LB7 would do it.

I did it with 26k in tow with my 01.:) That was 33k gross. Man those were the days. Coming down the other side was a whole different story. Set a new record for low speed, just to be on the safe side.:) Never again!

MaxmyDmax...Your entirely correct! What the truck is producing is "power heat" and as you may well know diesels run on heat...go figure

I've been pulling Baker grade (6% for 17 miles) at 26,ooo lbs. average weight in S. Cal most of the summer with ambient air temps at 105* plus and ground temps at over 140* and have not had ANY heating problems!!! Yes the temps go to 235*...ya just take your foot out the throttle and keep the rpm under 2300 and the truck works just fine!! And thats with the A/C running full blast. No I don't pull it 70 MPH but, with 35 years of driving a "BIG" truck its easier to go slowly up the hill than not at all!


All this with an '05 LLY Dually 2wrd, BD Power Pup on #1, down pipe, K&N filter! :rant:

I've got 75K miles on this truck in a years time and have yet to over heat it at all!

IMHO...if you can't drive a real truck like it was designed for...maybe you guys need to go back to your 1/2 ton gassers! Hell, you can overheat a C-16 Catapiller in a big truck if you don't know how to drive it!

With the same drag, towing heavy on flat ground it dont take really any more power to keep 15k at 60mph as it does to keep 30k at 60mph. That's not correct. Load due to rolling resistance does increase roughly proportional to increasing weight.

But for a 20k truck & a large cargo trailer, the rolling resistance is less load than aerodynamic drag at the lower range of 'normal' highway speeds. That changes with much heavier weights, where rolling resistance might equal aero drag. (see chart at left).

FYI: A truck & flat front trailer typically has more aero drag than a bus of similar frontal area.

Add a hill and then the work to do is doubled. It actually can be a lot more than doubled. At 55mph on a 6% grade, a 34,000 lb. coach requires over 400 wheel horsepower, nearly four times what it needs on a flat road. (see chart at right).

Charts below are from the Caterpillar publication "Understanding Coach/RV Performance" (55mph is the only speed shown on both charts)

MaxmyDmax...Your entirely correct! What the truck is producing is "power heat" and as you may well know diesels run on heat...go figure

I've been pulling Baker grade (6% for 17 miles) at 26,ooo lbs. average weight in S. Cal most of the summer with ambient air temps at 105* plus and ground temps at over 140* and have not had ANY heating problems!!! Yes the temps go to 235*...ya just take your foot out the throttle and keep the rpm under 2300 and the truck works just fine!! And thats with the A/C running full blast. No I don't pull it 70 MPH but, with 35 years of driving a "BIG" truck its easier to go slowly up the hill than not at all!


All this with an '05 LLY Dually 2wrd, BD Power Pup on #1, down pipe, K&N filter! :rant:

I've got 75K miles on this truck in a years time and have yet to over heat it at all!

IMHO...if you can't drive a real truck like it was designed for...maybe you guys need to go back to your 1/2 ton gassers! Hell, you can overheat a C-16 Catapiller in a big truck if you don't know how to drive it!

if this keeps up i think we will see a trend. i drive a big rig for a living too. i have a sneaking suspicion the "OHers" are trying to pull the hill too fast with the 300hp instead of using the 600lbs of torque, which is how a diesel is supposed to work.

Well an LB7 would do it.

doesnt change the fact.

doesnt change the fact.

Your right, it doesnt change the fact that the cooling system on the LLY isnt up to par.

MaxmyDmax...Your entirely correct! What the truck is producing is "power heat" and as you may well know diesels run on heat...go figure

I've been pulling Baker grade (6% for 17 miles) at 26,ooo lbs. average weight in S. Cal most of the summer with ambient air temps at 105* plus and ground temps at over 140* and have not had ANY heating problems!!! Yes the temps go to 235*...ya just take your foot out the throttle and keep the rpm under 2300 and the truck works just fine!! And thats with the A/C running full blast. No I don't pull it 70 MPH but, with 35 years of driving a "BIG" truck its easier to go slowly up the hill than not at all!


All this with an '05 LLY Dually 2wrd, BD Power Pup on #1, down pipe, K&N filter! :rant:

I've got 75K miles on this truck in a years time and have yet to over heat it at all!

IMHO...if you can't drive a real truck like it was designed for...maybe you guys need to go back to your 1/2 ton gassers! Hell, you can overheat a C-16 Catapiller in a big truck if you don't know how to drive it!


How are you measuring your ects?. Please don't say with the stock gauge because you are really closer to 245 or more. In my book you ARE overheating. If you don't mind 235+ degrees great, but it is slowly killing your truck.

60-70mph up baker grade with 14K??? i think im begining to understand the whole "OH problem".


60mph does not seem unreasonable with that weight at all being in spec. An lb7 can do it.

if this keeps up i think we will see a trend. i drive a big rig for a living too. i have a sneaking suspicion the "OHers" are trying to pull the hill too fast with the 300hp instead of using the 600lbs of torque, which is how a diesel is supposed to work.



:D :exactly: :D :exactly: :D

Ok guys,

What about people like myself hitting 250 ect(and I'mnot trying to do 90mph up the hills) while pulling a small 7k trailer? Am I not driving my diesel right when I overheat? Again, Why do other trucks(dodges,fords and LB7s do this without overheating) not have this problem. If there wasn't a problem with the lly GM would never buy them back from people or put on a X-box or the 06 CAI.

I really do listen to you guys that make a living pulling loads accross the country but I'm not pulling 40k behind me. I'm just trying to enjoy my vacation without my truck overheating. The main reason I bought a diesel is so I could hard charge those hills with my wimppy 7k 24ft trailer. Maybe I was wrong about diesel or just wrong on the choice of truck:( . Thousands of pages on overheating and still going strong. Somethings wrong with the lly IMHO.

You mean to tell me you cant hold your lly truck to the floor climbing up the side of a mountain at 75 for an hour while hauling 50k. What a pile!! These are light duty trucks, not semi's. When your toward the outer limitations of the truck, one must expect it to run a little warmer and should not drive it like a bat out of hell and expect it to run at 210 as normal whether the lb7 did it or not.

You mean to tell me you cant hold your lly truck to the floor climbing up the side of a mountain at 75 for an hour while hauling 50k. What a pile!! These are light duty trucks, not semi's. When your toward the outer limitations of the truck, one must expect it to run a little warmer and should not drive it like a bat out of hell and expect it to run at 210 as normal whether the lb7 did it or not.


I'm at 50% HALF of towing CAPACITY!!!!!! 7,000 pounds. The truck will not even run under 220 climbing a hill in the heat at 40mph.:rant:

The truck will not even run under 220 climbing a hill in the heat at 40mph.:rant:

Whats with 220? thats not overheating




With all this said I want to put a load and drive up a hill. Not hills like we have aroung here but big grades. Ive pulled 60k about half a mile before but it wasnt anything huge.

When your toward the outer limitations of the truck, one must expect it to run a little warmer and should not drive it like a bat out of hell and expect it to run at 210 as normal whether the lb7 did it or not.[/quote]


What makes the lb7 so special? Oh wait it's not an lly:)

Whats with 220? thats not overheating




With all this said I want to put a load and drive up a hill. Not hills like we have aroung here but big grades. Ive pulled 60k about half a mile before but it wasnt anything huge.


I never said 220 was overheating but I do think it is a little warm under the exact condition I stated.

I never said 220 was overheating but I do think it is a little warm under the exact condition I stated.


I dont see a problem with it. I run 210 empty. 10* for 7k seems fine.

I dont see a problem with it. I run 210 empty. 10* for 7k seems fine.

I never run at 210 empty. More like 195-205 even in the heat empty of course. I do not use the stock gauge to monitor my temps. I have seen it lye to me before:) .

Great you run 195 and i run 210. Ive got an overheater empty.

Great you run 195 and i run 210. Ive got an overheater empty.


What do you monitor your ect with? The stock gauge is not accurate at all. When my truck gauge is at 210 I'm really at 195 or so.

Your right, it doesnt change the fact that the cooling system on the LLY isnt up to par.

well i dont know about that. maybe not up to your driving style/experience "par". ive noticed very few if any 6 speed lly with the OH problem. coincidence? probably not.

well i dont know about that. maybe not up to your driving style/experience "par". ive noticed very few if any 6 speed lly with the OH problem. coincidence? probably not.


I have had the diesel tech at the dealership tell me to my face that the cooling system is not enough on the lly. Then he heated my truck up to 250 in a matter of a minute in his stall.

I don't know about big trucks and I don't care. What I do care about is what happens when I hit the hill with the cruise set at 3-5 over the speed limit. Usually when I hit the top of the hill, with a GM approved load, I am moving dangourosly slow, pukeing coolant. Driving style has nothing to due with it. I am driving the truck as intended. If the truck can not do this then it is not performing as it should. Plain and simple.

I don't know about big trucks and I don't care. What I do care about is what happens when I hit the hill with the cruise set at 3-5 over the speed limit. Usually when I hit the top of the hill, with a GM approved load, I am moving dangourosly slow, pukeing coolant. Driving style has nothing to due with it. I am driving the truck as intended. If the truck can not do this then it is not performing as it should. Plain and simple.


Comming from a man that owns several of these trucks and makes his living this way. Seams pretty cut and dry to me. Amen brother.:ro)

If the truck can not do this then it is not performing as it should.

:agreed:

Each of us have different personal comfort levels, and resultant definitions for too hot and over heat.

Using the OEM ECT gauge as an indicator of relative temperature:

1. What ECT do you consider too hot? Me; > 235.
2. What do you consider over heat? Me; DIC “Engine Overheated” indicator.

When my ECT exceeds 235, I throttle by the ECT gauge instead of the speedometer. Sometimes that means going slower, even though the truck has more than enough power to maintain the otherwise desired speed. And on rare occasions, that means pulling over to the side of the road, opening the hood, and letting the truck cool down.

My point is this. Based on the above rationale, my LLY has never over heated. Does that mean my truck is performing as it should? No.

What are your opinions? :)

well i dont know about that. maybe not up to your driving style/experience "par". ive noticed very few if any 6 speed lly with the OH problem. coincidence? probably not.


My LLY will hit 220 unloaded just trying to maintain speed up 7% grade for 1/2 mile. My LB7 will pull my 18,000 pound John Deere 550 up the hill and not reach a tick over 210. How does driving style have anything to do with this. The cooling system is not capable of rejecting the BTU's created by the engine plain and simple.


Waid:cool:

What is this thread about again? I thought it was just someone sharing some FYI info, not debating the never ending overheat issue. :rolleyes:

I have had the diesel tech at the dealership tell me to my face that the cooling system is not enough on the lly. Then he heated my truck up to 250 in a matter of a minute in his stall.

a "tech" at the "dealership", yeah i put a lot of faith in those guys, i wont even let them check my tires.

I don't know about big trucks and I don't care. What I do care about is what happens when I hit the hill with the cruise set at 3-5 over the speed limit. Usually when I hit the top of the hill, with a GM approved load, I am moving dangourosly slow, pukeing coolant. Driving style has nothing to due with it. I am driving the truck as intended. If the truck can not do this then it is not performing as it should. Plain and simple.


nothing is ever plain and simple, and not trying to be rude, or a smartass, but why do you keep buying dmaxes? i would NOT put up with any nonsense out of my dmax i use for recreational purposes, let alone if i used it for business. i was aware of the OH "condition" when i bought this "new to me" dmax, having had good luck with my last chevy. however any nonsense and it will be found in the used lot of the closest dodge dealer.

What is this thread about again? I thought it was just someone sharing some FYI info, not debating the never ending overheat issue. :rolleyes:

Looks on topic to me, we are talking about what it has been taking to heat up our LLY trucks :)


elvis I am not a statistics guy or a math guy whatever all you said sounds good to me. Without the math I can tell you less than rated weight will do you in if you try to maintain speed up a long grade if the drag is high. Like Turbobruce said, I got the truck so I could walk up hills, not so I would have to baby the throttle to stop overheat. When I do that I am not walking up the hill anymore, I am struggling to keep ANY speed to avoid pulling over like stevebos said.

Pulled over cooled off watching dodges and fords cruising by with similar loads makes you wonder. Even worse is when you started the hill with a 7.3 behind you and only a few miles into it he is outta sight ahead of you cause I had to let up to keep from blowing coolant all over. Oh wait, the truck let up first and cut my power during the climb. How come my new superior and more powerful dmax has to bow down to an old 7.3?

I know why: Ford built the 7.3 right and GM screwed the LLY up. :exactly:

a "tech" at the "dealership", yeah i put a lot of faith in those guys, i wont even let them check my tires.


Yeah your right. He is just an ASE certified mechanic for several years. I'm probably better off watching trucks on the weekends. Give me a break!!! I was there when he heated my truck up.

My LLY will hit 220 unloaded just trying to maintain speed up 7% grade for 1/2 mile. My LB7 will pull my 18,000 pound John Deere 550 up the hill and not reach a tick over 210. How does driving style have anything to do with this. The cooling system is not capable of rejecting the BTU's created by the engine plain and simple.


Waid:cool:

well yes 220 unloaded is overheating, how could you possibly pull any trailer if it runs that hot empty?

nothing is ever plain and simple, and not trying to be rude, or a smartass, but why do you keep buying dmaxes? i would NOT put up with any nonsense out of my dmax i use for recreational purposes, let alone if i used it for business. i was aware of the OH "condition" when i bought this "new to me" dmax, having had good luck with my last chevy. however any nonsense and it will be found in the used lot of the closest dodge dealer.

At least I wasn't aware that my truck was a possible overheater when I bought it new last July. No way in hell would I have bought a 40,000 truck if I though I could overheat it.

At least I wasn't aware that my truck was a possible overheater when I bought it new last July. No way in hell would I have bought a 40,000 truck if I though I could overheat it.

well that wasnt directed to you, but then why dont your trade yours? and i am intending to be civil in my discussion.

BTW, i can heat mine up sitting in my driveway......maybe i should apply for my ase cert.

well that wasnt directed to you, but then why dont your trade yours? and i am intending to be civil in my discussion.

BTW, i can heat mine up sitting in my driveway......maybe i should apply for my ase cert.

For one, the truck is paid off and I don't want a payment. Two, I will wait on a fix from GM. The reason he heated the truck up was to see when the fan would engauge. It did not come on until 227. IF peddling your truck is the answer to keeping it from overheating then cool. I prefer my equipment to work as advertised.

hey have 2004 diesel with lly. stock thinking about air intake, programmer and exhaust... what to you recommend...

hey have 2004 diesel with lly. stock thinking about air intake, programmer and exhaust... what to you recommend...

Search is your friend. Take it to the dealership and tell them you are overheating, they should install and 06 intake on your truck. The 06 intake are better than any aftermarket intake, if you are still under warranty it will be free.

Now back on topic.

well yes 220 unloaded is overheating, how could you possibly pull any trailer if it runs that hot empty?

To answer that, well I dont really pull anything with it, I bought a dodge:eek: and use my LB7 whenever I can.

nothing is ever plain and simple, and not trying to be rude, or a smartass, but why do you keep buying dmaxes? i would NOT put up with any nonsense out of my dmax i use for recreational purposes, let alone if i used it for business. i was aware of the OH "condition" when i bought this "new to me" dmax, having had good luck with my last chevy. however any nonsense and it will be found in the used lot of the closest dodge dealer.

Bottom line, Because they are still the best truck out there!:) I also have a great dealer mechanic!

ok at 210 the truck is just starting to get warm. there are two thomustats on the lly. one opens at 165 and lets coolent flow inside the engine. the second opens complety at 210 and lets flooded into the radiator. so 210 is not to hot. but what scares me is when i tose my direbike into the bed and go 35mph around 15 mile at maybe %9 and i am getting to 210. make me wounder what would happen with 15k on the goose neck. oh yeah i know what happens. had 17k on a 45ft flatbed going over vail pass in july. avaraged 35mph and 220* ect and 220* tranny-:t . i watch the comersial and the guy ripes past the semis with a full load. what gives, false advertising.

ok at 210 the truck is just starting to get warm. there are two thomustats on the lly. one opens at 165 and lets coolent flow inside the engine. the second opens complety at 210 and lets flooded into the radiator. so 210 is not to hot. but what scares me is when i tose my direbike into the bed and go 35mph around 15 mile at maybe %9 and i am getting to 210. make me wounder what would happen with 15k on the goose neck. oh yeah i know what happens. had 17k on a 45ft flatbed going over vail pass in july. avaraged 35mph and 220* ect and 220* tranny-:t . i watch the comersial and the guy ripes past the semis with a full load. what gives, false advertising.


I thought the second one is mostly open at 195..:confused:

Going down the road at 65 mph, on the freeway in 95 degree heat, lots of overpasses, gross weight of 20,450 I am barely getting to 203 and most of the time running at 196.. Those numbers are via the computer and not the gauge...

i thought it was 185 and 210??????? 210 was normal op temp and the 185 was to keep it from running too cool under no load in low amb temp????????

i thought it was 185 and 210??????? 210 was normal op temp and the 185 was to keep it from running too cool under no load in low amb temp????????

Here is what tex said about the subject last year when he tested them...

Max temp open is 230* (front stat), just as GM said on what RDL posted. However, I had info also from GM stating that it was 212*, so since there was a discrepency of 18* (too wide for my taste) I tested a bunch of stats, both off the shelf and the ones out of my truck so I would know.

The rear stat cracks at 180* and the front stat at 185*

Here is what KB said in reply


I agree with those numbers Tx. When I tested them, they cracked at about 185. Oddly, the ECM (http://www.dieselplace.com/forum/autolink.php?id=40&script=showthread&forumid=40) reports that as 195-200 (on this vehicle), best I could conclude. Add 10-12 degrees for an industry standard wax pellet range, you get 210 full open, if reading an ECM (http://www.dieselplace.com/forum/autolink.php?id=40&script=showthread&forumid=40) digital representation of the voltage the temp sensor is generating. (attitude or predator)

One of the few times they ever agreed :)

I am testing out a prototype electric fan setup designed for hauling bigger loads.. I got the numbers that I listed in the above post using the test rig... I am monitoring the temps on the laptop because of the inaccurate factory gauge.

Today I installed a stand alone gauge with a probe in the upper main rad hose. I can tell when the back stat opens by the sudden increase of temperatures and it's around 197 degrees..

I am monitoring the temps on the laptop because of the inaccurate factory gauge.



If I could not rely on my OEM gauge, I would make GM fix it. :D
Or buy my truck back. :exactly:

I don't trust factory temperature gauges. The Attitude monitor is on a pillar mount right there almost in line of sight and real easy to watch. The Attitude will say 125 when the factory gauge reads a little over 160. During normal highway driving the dash gauge pegs at one tick below 210 and will move only a very little bit while the Attitude can read anywhere from 187-198.

A friend says his Powerstroke runs 180, according to the factory gauge. I'd guess it's probably running hotter than that.

If I could not rely on my OEM gauge, I would make GM fix it. :D
Or buy my truck back. :exactly:


Hey GM already "fixed it" :mad: :mad:

So now it's my turn!

http://www.truckandrvreview.com/s9.jpg

Totally independent, of the factory system, water and oil temp gauges! Water is measured leaving the engine and oil is measured entering the engine after the factory oil cooler...

If I could not rely on my OEM gauge, I would make GM fix it. :D
Or buy my truck back. :exactly:


You hit this bickering between the V2 crowd and the EOC crowd (That’s what it is) right on the nail head. I'm sorry but this two year OH soap opera is so old and most people are losing interest due to the fact it's the same old people saying the same old stuff with just a new title for the thread every few weeks or months. It starts out civil and turns into a pissing match. The moderators jump in and save the day and it starts all over again and again. [/FONT][/COLOR]

I'm not trying to promote one option over the other (yes I see it this way, V2 or EOC which is better? That’s what all these threads boil down to) I think they both have merits. I think this OH thing is being beat to death. People can read between the lines and anyone who has been following this OH for the last two years knows that nothing more is being accomplished here. Heck now at KB's new home it’s starting all over again. "That lying ECT Gauge" yea that was a great thread. NOT.

This is what needs to happen IMO.

Install a aftermarket ECT and oil temp gauge in a Duramax and run it up a steep mountain pass in over 95 degree weather with a pre determined max load/drag. Then install the EOC and repeat the trip. Log results and temps for both runs and be done with it all. Let the buyer beware and make his choice.

I liked the EOC option but bottom line is KB never produced anything more than hearsay to promote his product. It seems the few of you supporting his product feel the same.....It works for me so I don't care if you want manufactures test data or not, I'm just gonna tell you it works so just buy it and see for yourself. I'm sorry but if you all believe the factory gauge is accurate enough to support and sell the EOC than I will never believe anything the EOC boys say. The Stock gauge IS NOT ACCURATE. We know this and have known for a long time and if you are using it instead of monitoring the actual temp with an external gauge to judge how you’re cooling mods are working than you are just reporting unverifiable worthless BS.

Is it so hard to understand all anybody has wanted to see for months and months now is actual test results to make a buy or not buy decision on. The lack of this data has been what all this fuss has been about. It just keeps getting hashed over and over again.

We are about to go into fall and the whole country will cool off. It will be to late soon and with out this accurately gathered data I’m afraid we will have to endure another winter of all the hearsay and bickering about unsubstantiated claims of this verses that. God help us!

Griz

:lol: . Still, it's all rather entertaining! Only a small waste of bandwidth. 2 years out and wanting a fix from GM,:muahaha: see ya back here next year, same DP channel, same DP time.

:lol: . Still, it's all rather entertaining! Only a small waste of bandwidth. 2 years out and wanting a fix from GM,:muahaha: see ya back here next year, same DP channel, same DP time.

Nope, I can careless what "GM" has for a fix. My proven and tested fix is siting in the garage waiting for me to get home from Iraq to install.

Cool My Duramax!
:cool2:

Quit frankly im tired of hearing about all the over heating stuff. The fact is our LiLlYs overheat and GM doesnt really seem to care. If you are that tired of it trade in for a LBZ or get an after market fix.

Thank you Mr. Grizwald.

The points you have made have been overlooked/ignored for too long.

The bickering can continue only as long as people are willing to support it. I was slightly roped into it in the "new place" and have decided to back out. It is tough to support folks when they are so close minded. Anyone want to argue about how the cooling system works? -:t

For those that are willing to have thier truck puke coolant or power down towing a hill the BB gassers, Ford 7.3s or Dodge trucks are doing, go ahead and continue to live in your world.

The rest of us have moved on. ):h


My driving habits are now approved by my Dmax!

Toyo you stated that it reached 235 but im not understanding weather the fan came on at 235 or came on but the temp continued to rise finally peaking at 235 where you halted the climb? Im having a recent issue with my fan coming on but only partial lock up to full lock up for a few seconds then back to partial, meanwhile the temp continues to climb. I feel like if my fan would lock to a roar which I found to happen erratically,,, it would maintain cool temps.

Fan was on controlling temps at 235, which it held for about 3/4 of a mile....and then I reached the end of the hill. At the end, I turned around and headed back down to my house. About 1/4 mile down the hill, the temps returned to normal.

Thank you Mr. Grizwald.

The points you have made have been overlooked/ignored for too long.

The bickering can continue only as long as people are willing to support it. I was slightly roped into it in the "new place" and have decided to back out. It is tough to support folks when they are so close minded. Anyone want to argue about how the cooling system works? -:t

For those that are willing to have thier truck puke coolant or power down towing a hill the BB gassers, Ford 7.3s or Dodge trucks are doing, go ahead and continue to live in your world.

The rest of us have moved on. ):h


My driving habits are now approved by my Dmax! :clap:

I can tell you work for GM cause thats the exact same propaganda they feed me at the dealer and on the phone. Deny deny deny deny!

I agree with you, it is what it is, and what it is for real is he got lucky that the temp was mild for this summer at 85-90 degrees. Try it again at 95-100 degrees, there is a world of difference. I always thought my truck was not an "overheater" until I tried pulling 14k and 13 feet tall up a long grade on a 97-98 degree day. He didn't say what the load was behind him either. Maybe low drag, but for sure the temperature was low.

All of you guys that have never actually pulled a high drag (as in 13 foot tall by 8 foot wide) heavy load (14k-15k) in high heat (95-100 degrees) up a long grade (5+ miles) that causes you to stay floored or above 90% throttle for 5 to 6 minutes or more are not helping things by telling everyone that all LLY trucks do not overheat. You have to have all of these coditions to get the wake up call. ALL OF THEM.

Am I bitter? YES, I sure am. I should be after getting ripped for $47,000 by GM and then have guys that have never towed a real load in real heat for extended periods tell me that they dont overheat. BS! Go try it! Otherwise be quiet about what you have no clue of!

Before a bunch of people jump me, make sure you have met ALL of the above conditions at the same time because if you have not then to be honest (sorry!) you just dont know what you are talking about!

OPINION: ALL LLY TRUCKS ARE OVERHEATERS, THE ONES THAT SAY THEY ARE NOT HAVE NOT KEPT THE TRUCK WORKING HARD LONG ENOUGH.


:rant:



I tow between 14 and 18k in 100+ heat all the time...no overheat, no alarms, no coolant puking, and i monitor the temps on my edge...235 IS NOT OVERHEATING, the hottest my truck has ever gotten is 235, and thats according to the edge...Yes my truck does get hot....****, what do i expect a 1 ton to do when im abusing the **** out of it...

And yes I tow huge hills, and yes im 12 feet high and 8 1/2 feet wide, so dont try to feed that bull****...

http://i32.photobucket.com/albums/d31/surfrippa/DSC00023.jpg

I tow between 14 and 18k in 100+ heat all the time...no overheat, no alarms, no coolant puking, and i monitor the temps on my edge...235 IS NOT OVERHEATING, the hottest my truck has ever gotten is 235, and thats according to the edge...Yes my truck does get hot....****, what do i expect a 1 ton to do when im abusing the **** out of it...

And yes I tow huge hills, and yes im 12 feet high and 8 1/2 feet wide, so dont try to feed that bull****...

http://i32.photobucket.com/albums/d31/surfrippa/DSC00023.jpg


thats a *****in set up you have there.

Also thanks Duramax~, you ever cruise Ocotillo Wells?

nope, i have a few buddies that have gone and have been invited but never made it. We are usually in the lucerne and stoddard valley area. Within the next few months we will have to check out ocotillo so if you need more people gimme a holler !!!

Cool, yeah i just got back from lucerne for the night race, if you ever go to ocotillo, PM me. Im there at least once a month...

Cool, yeah i just got back from lucerne for the night race, if you ever go to ocotillo, PM me. Im there at least once a month...


will do.

what was this thread originally about?

Carry on......

surfrippa,

And now the Rest of the Story. Thanks for your clear statements.

That's a Super Rig. :)

You are refreshing.