I just read through most of the "overheating" thread and it looked to me like my those who posted fell into three categories...

1. A small number of guys who have overheating issue or did in the past.
2. One or two guys who don't have an overheating problem but are obsessed in coming up with a solution.
3. Everyone else who is now staring at their temp guage waiting for something to go wrong!

So, overheating is defined as the alarm going off (red light flashing - overheat shown on DIC). Mods are different tires, programmer boxes, or exhaust, etc - anything that might throw off the digital controls on the truck.

- jeff

I have an 04.5 that overheats and my 05 flashed the overheat on the dic today.

I have an 04.5 that overheats and my 05 flashed the overheat on the dic today.

Rick were you towing at the when the overheating occured?

I don't overheat at all. I have often thought of doing a poll like this. I think if you ran a poll that weeded out altitude or not versus overheating or not you would find a correlation to altitude on the overheating and a high percentage of trucks overheating.

Also, I don't think the number of people that overheat and are ACTIVE in the thread gives a very good indication of the number that has the problem. Sprinkled throughout the thread are guys that come out and post only one time, saying they overheat, have been watching the thread for a long time, just never commented until then.

So on the surface it may seem like a "small number" but like an iceberg there is a huge mass below not readily apparent.

Does Rick get to vote like 3 times since he has three that overheat?

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I voted 04.5 Stock runs fine but haven't towed heavy yet. The fan does cycle on a lot when temps are in the 90's towing 7,000 so I am watching the thread with some interest.

Thats the other big qualifier. TOW HEAVY. I already wonder how many of the 04 and 05 (especially 05 the trucks being so new) guys that voted "runs fine" ever actually tow heavy. Like 4 wheel drive, most people never actually use the tow capability for REAL as in BIG HEAVY LOADS.

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My son pulled my trailer yesterday loaded with a car.....plus tools, etc. in the back, 90+ degree heat, strong winds. He said the temp never raised even slightly from normal, and he hardly knew the trailer was behind him......he was impressed.


05 Chevrolet Duramax/Allison - no mods

Like Tx said - towing and at altitude are the factors to watch for. Mine never overheated but I never pulled a real load with it - but I am sure at altitude with a load mine would overheat.

The problem really comes out when you tow 10-12k or more at altitude. Towing a car or a boat does not compare, it isn't enough weight. I doubt the car and trailer and tools was even 6000lbs.

A bigger heavier load almost always includes power robbing drag as well, which my boat and your car being towed do not present.

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My 'heavy' towing is a 7800 lb camper in the flat lands of Wisc. Not that big of a load at all. Two weeks ago pulled some hills in Iowa on 61 South down to Davenport. I was impressed, the truck was not. It didn't know the hills was there. My post-pyro went from 500 pulling flat up to 950 pulling the 6% and 8% grades.

Weight has alot to do with it.When pulling an open trailer with race car around 4,500-5,000 # the temp never really moves but with around 8,500 # travel trailer it hits about 220-230 on big hills.If you add another 4,000 # or so I'd probably be on the side of the road.Just put on a 4" mbrp last week and hope this helps get the heat out from under the hood.Has anybody seen any help from doing this?

With the edge on level 0 which I think affects timing only, I have more problems with over heating than if I have it on level 2. This may be because of the power requirements to move the heavy loads. I have never had it puke coolant or show over heat on the dic, but I have always reduced the throttle to prevent the dreaded having to pull over. I have had the edge hit 239 degrees, this pulling 14,000->20,000#, 60-70 mph, running a 2->5 mile hills, ?? grade @ 75->85 degrees, and 3400->4500 ft elevation. The only time I hear the fan is after 237 degrees and by then I think it is to late. I'm getting the fan replaced as I type this.

mine will overheat every time pulling 14000 lb fifth around 8000'. i did pull it through utah once which is around 4000' and never had a problem. if i keep the weight around 6000 to 8000lb it will be fine at 8000'. it just doenst like anything over about 12000at highier elevation. the part that makes me mad is my 03 duramax will pull the 14000 anywhere with no heating problems.

I have an 2005 stock truck and it has never overheated. But I've never towed any load whatsoever. I would like to think everything is ok, but since I don't have anything to tow, it may be a long time before I know for sure.

I ,Like RDL tow! My empty wieght with trailer on is 17800, Quite often I am at the Gross for the truck, Altitude is a huge factor and the length and % of the grade are huge, this truck will pull a 5 or 6% grade with 20,000 on at 60 + no problem ,but if it is more than a couple of miles I am in trouble , Bells /lites/shut down, almost everytime and more since summer,but will get hot at 37 Degrees OAT, I think the poll should qualify "towing loads in excess of 8,000 minimum , these trucks don't know they are towing until then.

good point carhauler.
what are you pulling with ?

the only time mine has wanted to think about overheating was pulling my 7x16 cargo trailer, it has the flat front on it catching alot of wind. i was heading up grade on I66 out of DC almost to I81 on the WV line.

no mods at the time.

I agree with carhualer and the others that have said these trucks no not know they are hualing unless the load is over 8K. My truck only heats up when I tow my 12500 lb. fifth wheel over mountian grades. The truck works perfect when empty or lightly loaded or on flat ground with a heavy load. However, I bought it to tow my trailer to the mountians in the summer time! I feel GM needs to step up to the plate and admit the overheating problems some of thier trucks are having and start solving them.

ssduramax, I have a 2004.5 LLY CC DRW ,I have had the problem since new ,pulling a 48 ft 2 car enclosed, Chevy is in process with there race people building me a rad and talking about a hood and other airflow mods at the dealer, I hope this will help ,if they at least try ,I can't ask for more for know.

IMHO, towing that brings out "overheating" issues requires a trailer at least 10k lbs and a fairly large surface for wind resisance such as the image below

http://img342.imageshack.us/img342/6182/combo8gw.jpg

I don't 'overheat' as I never let it get that far. I can get it to move from 210 (on the analog gauge) even at close to sea level.
I am towing close to 12K. i can make the temp rise on a freeway on ramp.

On longer hills I can get it to 230+ very easy. At that time I back off and or turn on the heat.
At elevation is seems the same but the highest I get is 4500 feet.

I installed the cat delete pipe and a week later the glow plug light will not shut off when the motor is cool and the check engine light is on. It's at the dealer now. I also asked them to look into the code update for the ECM. He had no clue what I was talking about. I will know more later.

I plan on towing again in July 22nd. Will see how it does.

IMHO, towing that brings out "overheating" issues requires a trailer at least 10k lbs and a fairly large surface for wind resisance such as the image below

http://img342.imageshack.us/img342/6182/combo8gw.jpg

Hi Cadent -
You were one of the original folks with overheating issues. I saw that they did a goodwill swap (04.5 for your new 05); Have you seen any issues with your new '05?

BTW - nice looking rig! :)

thanks,
jeff

My '05 with mods has never overheated empty or towing. I have towed my 36' 5er (GVWR of 12,500#) estimated to be actually around 11,500# with no issues to date. I am going out west to Yellowstone at the end of next month, and sure hope it does not decide to start!

I couldn't be happier with this thing and hope you guys with overheating issues get a resolution soon!

I tow all the time in the mountains in colo.with no problem,with my 05 LLY.The fan kicks on once in a blue moon at temps above 90.

Hi Cadent -
You were one of the original folks with overheating issues. I saw that they did a goodwill swap (04.5 for your new 05); Have you seen any issues with your new '05?

BTW - nice looking rig!

thanks,
jeff


So far my 05 has performed well. However, I have taken a few steps to ensure that this truck does not have the same or similar problem; I have removed the kitty, installed a 4" MBRP exhaust, put in the egr blocker plate, installed a "fingers stick", programmed the truck at level 2 with a Hypertech, and installed a MikeL cooler. From the beginning this truck did feel better (i.e. the clutch fan does not engage as much as the 04.5, and the mileage seemed better)

Even though the general was “kind enough” to do a “goodwill buy back”, it did cost me some money. They would not negotiate and did charge me for mileage used from the first report of this problem and would not reimburse me for the “extras” I added to the truck. I can’t remember the exact percentage they offered to pay for, but I think it was 30%, so I was only able to include the items that could not be reinstalled, (window tint & the spray-on bedliner). I had to remove and reinstall my 5th wheel hitch, “leveling kit”, and rear air bags.

Overall it was barely a “fair” deal, it did cost me about $3,000, but I put over 13k miles on the 04.5, and I got my replacement truck at “supplier price” (thanks to the dealer), minus a $2,500 rebate. I guess I could have fought them harder, but GM has the time and the money on their side, and quite frankly the general could really care a less about their customers. Did I also mention that I had to hire an attorney to get them to do this? Of course the attorney fees were ultimately paid for by GM, but GM would not acknowledge me or this issue prior to involving the attorney. My hope is that this issue will get resolved and that some hot shot attorney gets wind of this and files a class action lawsuit to get us all compensation for their flawed design and the fact that we and our families are put in harms way due to this issue.
:rant:

BTW - Thanks!

Cadent...Nice rig, looks a lot like mine.

I have pilled my 5er to Colorado twice with my 04.5 and the only time it has ever overheated was this last july while climbing a nine mile 7% grade just east of Pagosa Springs Co.. I was chasing my cousin in his motorhome and I noticed my D.I.C. display telling me I had a high coolant level, this was about mile seven of nine, I just backed out of it a little and once I got to the top (10,850' elevation) I let it idle about five minutes and the temp was back to normal. Normal for my truck is one peg below 210 degree mark. I remember the outside temp was around 90 degrees, I was getting worried because we go to Colorado in July to escape the central Valley heat. Anyway that was the one and only time I have ever seen the coolant level get over 210, it ran fine the rest of the summer til we got home and I could no longer afford to drive it because of the outrageous diesel prices. (Just kidding)

It does turn out that the truck can't pull an extended 8% (very few people have access to a true 8% for 10 miles) grade, 110 degree day, with a legal 23K total. Perfect storm.

Granted, most people won't get themselve into that set of conditions.

Truth is all these trucks suffer performance losses just getting close to these conditions, AC, mpg, power. Doesn't take much to improve it though.

I know this is not a discussion thread, so I'll let it go. Thanks for the insight.

Outside temp has a lot to do with engine temp. AZ pulls when triple digits play a roll makes mine get pretty warm. When i get up to cooler temps, I dont see higher engine temps as much. Never have seen over 130 degrees.

Anyway I don't know how to enter the poll, My truck has only got hot once in the past two trips, what should I enter on the poll???

Can't really answer the poll honestly because I don't know the answer on my truck. In June, I pulled from the midwest through Colorado and up to WA state with a 24' enclosed car hauler which scaled just over 9k lbs (if I remember right, the highest mountain passes we drove through were around 7k ft). OATs throughout the trip ran between high 70's and 80's depending on elevation. I fought a pretty good headwind seemed like most of the way. Drove most of the trip between 70 and 75mph. The truck is an '05 GMC 2500 CCSB 4WD and was bone stock at the time and just over the break-in mileage.

I did not overheat or really get much above 210 ECT. However, the fan was on A LOT. Thought I'd wear the damn thing out. My previous truck was an '03 Chevy 2500 CCSB 4WD. I towed the same trailer with it and I don't remember the fan cycling as much.

So, not sure I could give a direct answer to the poll. Mine hasn't overheated, but if any of the above variables changed for the worse (more GW, higher temp, or greater elevation), I think it is a distinct possibility I'd be in the overheat group.

My truck overheated with or with out mods I tried mbrp cool duals no kitty afe stge 2 intake o5 hood and grill,banks six gun,bully dog power pup,removed bumper and grill,It seems that my truck is getting worse the more it overheats

I voted "NO - 4.5 stock truck runs fine", but like others have said, I suspect I would be in the "YES" category under more demanding conditions. I tow a 30' 5th wheel that weighs about 9000 fully loaded, so my GCVW is only about 16000, not too close to the 22000 limit. Here on the east coast there are some steep grades, but most of them are not all that long, and elevation rarely exceeds 3500 ft. The fan has come on a few times on these grades, but it cools things off pretty quick so the DIC has never indicated an overheat condition. I did have one occasion where, after the fan had come on a couple times while towing on a hot (90 degree) day, it seemed there was a loss of power for the rest of the trip that day. Not so much as to make towing impossible, but enough that it seemed like I was in one gear lower than normal much of the time. My main concern is what will happen when we take a trip out west next year and encounter some real hot days and high elevations.

Looks like the poll tells the story... 17% have overheating issues at some time. The other 83% don't...

Just towed my 3/4 ton Suburban on a Big Tex 70DM and about 2500 lbs. of supplies, gas, diesel and equipment down to Gulfport to clean up my mother's house from the hurricane damage and camp for a week. Probably about 9500 towed (including trailer weight) and 2000 in the bed all told. It was about 93 degrees and we cruised at 75 - 80 on pretty flat ground. It stayed at about 200 as it always does and got 12.5 mpg per hand and Dic.