Just got back from a trip to Utah, pulling my 8000lb. fifth wheel and a ATV trailer with four ATV's behind that. My egt's got up to 1300 degrees a couple of times what is the maximum i should go to before backing off the throttle? i have heard 1400 and 1300 but 1300 seems to be what everyone is saying, so i thought i would ask the experts. Just going down the road (with camper and trailer)at say 70-75 mph the egt's stay somewhere around 800-1000 degrees.

04.5 LLY AFE cold air intake stage II, Hypertech programer stage 2 and MPRP cat back.

I back off at 1300 myself, otherwise your EGT's are about the same as mine.

I got it up to about 1350 and backed off, i think if i don't go any farther than that i should be safe. I just happen to have a lead foot. What will a boost gauge tell me about the engine?

Robo, IIRC several Hypertech users have posted they run fairly high EGT's when towing. Hitting 1300-1350 for very short periods in and of itself isn't going to permanently damage your engine. Now wide out throttle up a 7-8% grade with a heavy load for several miles and your cooking the engine and turbo. :o:

Hitting EGT's that high at 8k lbs is unusual since that is a pretty light load for these trucks. Were you up in the RPM range when the EGT's hit that high? :confused: That's when you will see the highest boost and EGT's.

You might entertain either killing the kitty or punching some holes through it to improve exhaust flow. Also wouldn't recommend that you pull on very high Hypertech settings. At least you have an EGT gauge so you can monitor things. :o:

Oh yeah, one final thought: SLOW YO' A$$ DOWN BABY! ):h JJ :)

Altitude! Makes a huge difference in EGT - 200-300 degrees higher under similiar conditions. I set my personal limit at 1280 degrees, but with anyone else driving, I lowered it to 1200, and I try to stay away from the 1280 myself. As I tow a lot over 5000' altitude, it is a bit hard to do.

I was climbing some slight grades when i hit those temps, so i hate to see how much a long steep pull will affect it. I may try to drop that Hypertech to stage 1 and see if that helps, but then there goes the purpose of the programmer. Thanks and yes i need to slow it down but thats why i got the Duramax to hall A**.

Robo, until you get the tranny upgraded you really don't want to tow in very high settings anyway. Besides, towing a travel trailer and hauling ass are potential disasters just waiting to happen. Now normal street driving is a different story altogether. :cool:

Horse Trainer, your post reminded me that it is just about time to revive the "Overheating LLY" thread. You are correct that things seem to heat up much faster at higher altitude with these trucks. EGT's coupled with the engine/tranny pushing heat to the radiator, A/C running, and the IC appear to overwhelm the stack on certain LLY's. Unfortunately I haven't heard from or seen any posts from the principals involved in that thread, mainly Masterp2, TxChristopher and Cadent45. Guys, you out there? :o:

I'm going to bump the overheating thread and get it back on the radar screen. We're starting to see temps in the 80's around the country now. Guys at higher altitudes should be posting results of their reflashed trucks, tranny coolers, etc. I'm curious to see if the 05's suffer the same fate. :confused: :confused:

Later. JJ :)

how long were the hills you were pulling?


Guys,

Would it be safe to assume that part of the reason he was seeing such high temps was because of the high altitude? How much difference would that make?

General concensus seems to be that short bursts into the 1300-1350* range won't kill your truck, but extended runs will deteriorate the internal parts of the engine and longevity will suffer. :o:

Duckhunter, you might want to read up on the "Engine overheating" thread in the LLY forum. They do a very good job of explaining what happens to these trucks at high boost and high altitude. Too complicated for ol' JJ to explain. Best to read up on it for yourself. JJ :)

But I guess it is safe to say that the EGT temps were worse than an identical situation at a lower altitude?

I tried to keep up with that thread but it got entirely too big :)

I had forgotten just how long that thread was. :eek: In a nutshell, at high boost at higher altitudes for sustained periods we suspect the stack is unable to dissipate the additional heat created. JJ :)

But that overheating issue is regarding motor heat, not exhaust temps, right?

Oh boy, techie stuff! :o: Your question is a tad over my head and best answered by one of the techie types. But I believe I recall their discussions sufficiently to have a stab at it. Guys, chime in if I screw this up. ):h

IIRC the intercooler recirculates a considerable amount of hot exhaust gas which adds heat to the stack. IIRC it sits right in front of the radiator. This additional heat is then passed on to the radiator. Appears there is a point where the radiator is unable to shed this additional heat, especially when coupled with the heat from the engine coolant and tranny fluid at higher rpm's while climbing. This is when the engine begins to overheat. The reason altitude has an affect is because the stack isn't as efficient at shedding heat at higher altitudes. I may have mucked that up a bit, but hopefully you get the jest. :D

Hopefully TxChristopher, Fingers, Masterp2 or one of the guys that lived/breathed that post and are techie qualified can chime in. Later. JJ :)

I have high EGT issues as well. Towing 12k'ish pounds from sea level to 4000'. I can get it to 1400 if I want to. I back out of it to keep it around 1250ish.
BUT! The motor gets warm, 230-240ish. I have to open all windows and crank up the heat to keep it cool.

I do have a billet grill that I feel restricts air flo and will be removing it this weekend and towing (in heat) the following weekend. I hope removing it helps some but I kinda doubt it will cure my issue.

JJ, thanks for the explanation. So it sounds like EGTs and engine temps are somewhat related...


Well, during my little pull I never really worked the engine or even got the temp gauge to budge. I would think that I did not get the EGTs up too high.

Mike, what kind of power adder are you running?

My Egt Get About 1250 To 1325 Towing Up Large Grades . I Think My 38.5 Tires Have Something To Do With It . And That Is Towing 10 000 Pounds .

Mike330R,

Awesome freakin' truck dude! I took the time to look at your pictures, one of the nicest D'Max's I've seen on the DP, especially for off-roading! As for towing, now that's another story! :o:

Several things are likely working against you: large/wide tires; lifted truck; spot lights and billet grille insert(air restriction). Is the 12k lb trailer a 5ver or ball mount? :confused: While the taller tires fill in the wheel wells on these trucks they also affect the final gear ratio. For normal driving it may take a little more time to get "off the line" than with the OEM tires, but for towing it makes it much harder for the engine/tranny to get the "power to the ground". You end up having to push the engine/tranny harder to maintain speed while towing. Some guys keep their OEM tires just to tow with if they don't tow that often. ;)

Someone already asked if you are running any programmers, ??? I have the same billet grille insert and ran high engine temps like you. I ended up cutting away most of the OEM grille behind it and left just enough to secure the grille to it. Seems to be holding up well and improved air flow across the stack. You did not overheat your truck at 230-240*. IIRC GM says 275* or higher is considered overheated and will throw an overheat code. That being said, from what we've discerned so far on the overheating post that 230-240* temp range is about the point where the DMax starts going into overheat mode if you don't back off the pedal. -:t

dieselman, I suspect you are correct! :exactly: JJ :)

My Egt Get About 1250 To 1325 Towing Up Large Grades . I Think My 38.5 Tires Have Something To Do With It . And That Is Towing 10 000 Pounds .

What power level are you running on?

I tend to think my EGT's are on the high side also. :(:( I just hooked up my edge Juicer/ Attitude last week and Towing my 24' bumper pull enclosed car trailer. maybe 5000 # my EGT's at 70 mph were in the high 900 to 1100 when passing someone on a flat road at sea level.. Does that sound high to you guys

i was driving through the mountains of pa , i was in hypertech level 3, i wasnt paying much attention to my et guage ,i wasnt pulling anything and i had no load in truck, i was going around 55 to 60 up some 5 percent grades ,i looked at my et guage it was around 1500, i backed off, i had to go 45 mph to keep it around 1200 i have a cat back 4 in magna flow exhaust and an air raid intake . i was shocked that ets where so high . i had the cat cleaned out got the honey comb chisled out, towing 12 k trailor my ets, its easy to go over 1200 on hypertech level 2 going up grades .

You guys are scarin me bad! I just put a Superchip in and am going to tow next week over Wolf Creek pass in Colo. , about 13000' . A Pyrometer is on its way, and hope I get it in , but I will stay in the first stage for sure. I know one thing leads to another,,I hope I can avoid the $600 for a bigger exhaust. Time will tell, I would like to tow in the 2nd stage, but am at the recommended max. I hope Moderators dont kick my a$$, I just posted in the exhaust section when I realized it should have been here. Thats twice this weekend,,geez!!!
Frank
:iamwithst

chevsforever, welcome to the world of diesel engines. While they produce tremendous power/torque and love to work hard, they can generate quite a bit of heat, sort of like a boiler. ;)

IMHO anyone that runs a programmer and plans to tow needs to consider upgrading to a high flow exhaust. An absolute minimum is a pyro gauge which I see you have on order. :) You can't manage EGT's if you don't know what they are. :eek: Backing off the accelerator will immediately lower EGT's, just avoid high rpms/boost for extended periods. Plenty of intel here on the DP. :rolleyes: You didn't mention how heavy you would be towing? Best to plan on an exhaust from Santa. ;) JJ :)

From my experience over the last couple months pulling my fifth wheel and ATV's around with the Juice/Attitude. I dont really see any advantages over pulling stock or pulling with the Edge, with the Edge the egt's run hotter and get hotter faster.(same thing happened with my Hypertech) I am probably going to start towing in stock, i am just not convinced that these high performance chips etc. are made for towing, But they are awesome when your empty. Just my .2

ROBO

What you suspect can be explained with a little physical science. HPs spin the wheels at high RPM's, so the lighter the vehicle with lots of HPs.....i.e. Italian sports cars, the deeper you sink in the seat. Torque is twisting force through the driver train to where the rubber meets the road. The heavier the load, the more torque required to set this load into motion. Diesel TQ is developed at low RPMs, based on the fuel's efficiency (roughly 90% of it is turned into energy when burned). When more TQ is required, such as take-offs, acceleration, or hill climbing, more fuel is consumed, and more heat is generated. As the weight to put into motion is increased, the more fuel is required/consumed and more heat is generated. This heat must be dissipated or expelled at the same rate that it is being generated or a melt-down will occur (Re: British Thermal Units).

When your Diesel truck is used as a "toy", increasing HP and TQ to do burn-outs, hole-shots, and skunking Ds & Fs can be fun. But when you Diesel truck is a "tool" for making business profit, then reliability and efficiency becomes much more important. I tow heavy, tow often, and tow for profit, so in my opinion, my "tool" stays "cool" by staying the way the maker made it (think clean thoughts here).

RF

:exactly: I agree, i was trying to explain that the use of programmers, chips etc. dont have a huge effect when towing except to get your egt's hotter than they should be. I haven't noticed any serious performance gains while towing. I will probably be removing the Edge and going back to stock, with the exception of the exhaust and AFE.

Right On RF !

Idahofox

Glad I found this thread! My Dmax is bone stock and I will be heading west this fall (Yellowstone/Tetons) I will be hauling my 5er that weighs in about 9500lbs. In your opinions, do I need an EGT or larger exhaust?
I usually keep my speeds around 60-65 when towing and probably will be a bit slower on the hills.

Rookiew, IMHO if you are going to tow you need an EGT gauge at a minimum. Even stock you can/will hit some pretty high EGT's when towing in moutains and long grades. A high flow exhaust will help reduce EGT's, but without removing the CAT the benefits are pretty negligible IMHO. ;)

RF3, the only caveat I would make with the programmers is there are times when programmers can actually help to keep EGT's down. Yes they generally do add more fuel in order to produce more hp/tq, but that additional hp/tq does allow the Ally to stay in a higher gear range while towing inclines or hills. :)

I have the E/J w/attitude, so I have the ability to change power settings while towing. Reducing the power level to zero I get much more engine clatter and more downshifting on light grades/climbs. On flat surfaces EGT's are a bit lower stock, but pretty negligible (20*-30* max) when compared to the additional hp/tq the programmer provides. Also, my EGT's are much higher when I downshift and increase boost and rpm's. I don't downshift near as often with the programmer. ;) IIRC this is a fairly consistent concensus amongst those towing with programmers. :confused:

So I agree with the premise of your post, but like most everything there are variables that could be brought into play. Ironically I never had any intentions of modding my truck when I bought it. While GM has built a pretty decent platform there are areas for improvement. :rolleyes:

To each his own on the mods. For now I'll keep using the E/J, not only for more hp/tq but for engine and tranny protection as well. :ro) Good discussion. JJ :)

Some additional intel that might be useful. TxChristoper posted: When a tuner/box is placed on the truck, it substantially raises the power curve of the engine through its entire operating range. The tuners/boxes do raise boost, but just because they do does not mean you will need 100% of it to get the job done. You can get the same work done with part throttle than a stock truck can at full throttle. They bring in the power especially down low, not through boost only but through boost and fuel pulse timing and duration.

The superior power allows your truck to get a handle on the load sooner and with less throttle at the bottom of the hill in the same spot that the stock truck is losing speed and is demanding full or close to full throttle to maintain the same rate. Boost is power in our vehicles, that is for sure. Before my tuner, the truck was flat and lazy until 2500rpm and maybe even 2700rpm but now the power is there early and comes in real strong at 1800rpm.

I can readily walk away from a stock truck and not be near full throttle on mine.

Might help explain what I was trying to say. JJ :)

I tow with h-tech on L3 all the time. TT 25' about 8,000 loaded and I rarely hit 1250. I can hit it if I leave my foot in it up a grade and want to do 75-80 but if you keep the speeds around 55-60 I don't normally have an issue.

If the egt's start to get hot, put it in t/h. That will bring the temps down about 200 degrees in most cases. I would also recommend removing the cat. That has a large impact, at least in my case.

Since I Got The Kitty Degutted I Can Keep It In Hypertech Level 3 Going Up Steep Grades Is No Problem. Now When Im Towing I Keep My Eyes On The Et Guage When Im Going Up Steep Grades I Can Go Up At 45 To 55 Mph On Steep Curvey Single Lane Roads .

does anyone use a banks six gun bundle? I have one and with a 36 foot fifth wheel my egt's reach 1350 on hills (small inclines). Even in setting one (factory settings) my egt's hit 1200. I never had high coolant or tranny temps though. My truck is a 05 DRW extended cab. I had no idea there was a problem with that. Is there any one who is not seeing that problem?