Overheating Problem

sleepless

Member
We have a 2008 GMC Sierra, 2500HD, duramax diesel, extended cab, 2wd. Towing a new 3400RE which should be within the weight limits. I'm having problems with the truck overheating on the passes. I'm worried that it could be the Edge Evolution product that I had installed to improve performance. Or it could be that I'm not using the "towing capabilities" correctly. I usually just leave it in "Drive" rather than putting the transmission in "Manual" and changing gears that way. Any suggestions?
Thanks in advance. Going over more passes tomorrow.
 

Barry & Alana

Active Member
Try the tow-haul mode. We have the same truck - (4x4) this truck should not be overheating. You might have to take it in to a dealer for a a checkup.
 

ct0218

Well-known member
With a load that heavy use the Tow/Haul mode. That changes your shift timing and helps with braking (Allison downshifting). Any chip or programmer increases performance by dumping more fuel into the engine, and that certainly will mean more heat. Use a lower performance setting, get an exhaust temperature gauge and pyrometer (and keep an eye on it), and take the pass a little slower.

Guess my mind was ahead of my fingers--meant "or" there, the "and" was meant for after pyrometer, and it looks like I got it screwed up when I added the parenthesis.
 
Last edited:

beardedone

Beardedone
Don't buy both gauges as they are the same thing. Ask for an EGT ( exhaust gas temperature) gauge. They are technically a pyro gauge but now more commonly known as an EGT. A little money plus installation but worth it when you have an engine overheating issue.
 

Forrest Fetherolf

Senior Member
We have a 2008 GMC Sierra, 2500HD, duramax diesel, extended cab, 2wd. Towing a new 3400RE which should be within the weight limits. I'm having problems with the truck overheating on the passes. I'm worried that it could be the Edge Evolution product that I had installed to improve performance. Or it could be that I'm not using the "towing capabilities" correctly. I usually just leave it in "Drive" rather than putting the transmission in "Manual" and changing gears that way. Any suggestions?
Thanks in advance. Going over more passes tomorrow.

Get rid of the Edge before you hurt something....you don't need any more performance, anytime you hook up..........only run in tow/haul mode. I pull a 3600RL with stock 06 Duramax 6 spd Allison, it has plenty of power and no overheating problems. Traveling from CA to WA, TX, IL, and PA, 24K miles, I haven't found any grade that I can't maintain 55-60 mph and no other 5ers this size have passed me.

Forrest
 

sleepless

Member
Thanks for all of the useful suggestions. I probably wasn't clear about one thing. I always run in tow/haul mode but I usually don't put the transmission into manual unless I'm going down a steep hill as then I can use the transmission to help slow me down. Is this good driving technique?
 

Delaine and Lindy

Well-known member
The first thing I would do is remove the Gadget. I have never had a heating problem and have pull the Rockies with Gross weight of 25,600 and I also owned a 2005 GM Truck that some people had a over heating problem. Also when in the hill and mountains I would leave it in tow haul mode it will take care of the downgrades. If you overheat that Duramax something will break, and then I hope you have deep pockets, $12,000 plus to replace that Duramax. And GM knows now you have installed that Gadget. The Duramax has all the HP and Torq need to pull most of the 5th wheels out there. I also would never put a Gadget on my Truck it just isn't needed. It's your Truck so the choice is yours. GBY...
 

creeper

Well-known member
The 3400RE would put you nearly all your weight ratings. I was looking at a GMC 3500 but my 3400rl exceeded nearly all the weight ratings.

Take off the edge before it does damage and you get a big repair bill.
 

Ray LeTourneau

Senior Member - Past Moderator
The 3400RE would put you nearly all your weight ratings. I was looking at a GMC 3500 but my 3400rl exceeded nearly all the weight ratings.

Take off the edge before it does damage and you get a big repair bill.
Creeper, You mentioned the 3400RL exceeding the rating capasities of the GMC3500. Were you referring to a single rear or duallie? We have a 3400RL that scales at 14,400 and a Chev 3500 duallie and are not over weight at all. Can you clarify please? Thanks.
 

mountainlovers76

Mississippi Chapter Leaders
I have the 2008 GMC Sierra with the 6.6 Duramax also, only in a 4X4, and I have done a lot of mountian towing with it already this year. I pull a 3600RE and have not had any problems with overheating and I have been on some pretty long and steep grades this summer. In fact, the engine and trans have stayed surprisingly cool compared to what I was expecting. I also use the tow/haul mode in auto as you do most of the time. Only a couple of times have I used the manual mode to ease down a mountain. I would not add anything to improve performance on the later model Duramax engines. They really do not need it, and in fact can hurt it.
 

jmgratz

Original Owners Club Member
I know the Ford is not the same but, I had overheating problems just once so far and when I took it to the dealer they found that the radiator was clogged with bugs. Not the inside but the outside. The radiator was cleaned and no more overheating. I have now put a window screen in front of the radiator and when it gets clogged and I cannot wash it off I replace the screen. It is cheaper than the $800 it cost to get the radiator cleaned. If you drive in the south in the fall or spring the love bugs will clog up the radiator. Just a thought
 

Larryheadhunter

X-Rookies Still Luving it
I own a Ford f 250 and also a 2009 3400RE and according to Ford I can haul 15,700 lbs. The 3400RE weighs in max at 14,800 lbs. I was told by both Ford and many others on this forum that using additional help like the edge is bad for the truck and at least for me would void my warranty. Some disagree with the warranty issue, but thats what both corporate Ford and my local dealer told me.
 

newbie

Northern Virginia
We have a 2008 GMC Sierra, 2500HD, duramax diesel, extended cab, 2wd. Towing a new 3400RE which should be within the weight limits. I'm having problems with the truck overheating on the passes. I'm worried that it could be the Edge Evolution product that I had installed to improve performance. Or it could be that I'm not using the "towing capabilities" correctly. I usually just leave it in "Drive" rather than putting the transmission in "Manual" and changing gears that way. Any suggestions?
Thanks in advance. Going over more passes tomorrow.

I have the same truck but a crew cab 4x4.

I agree with the consensus here that the cause of the over heating is the Edge Evolution product. In fact, the owner’s manual warns that after-market performance products can cause overheating and engine damage.

Our Landmark is heavier than the 3400RE and stays at normal operating temperature.

Edit- I should add that the GMC has no probelm pulling the Landmark.

Good luck,
John
 

Uncle Rog

Well-known member
I have been toying with the idea of using a tuner for a while now. I opted to first improve the intake / exhaust syatems and am delighted to report that the improved mileage, 1-2+ miles better, and the noticable power increase has cured me, at least for now, of considering the computer mod. The engine is also running cooler on the long, steep grades. Today I am having the Allison, transfer case, and differentials serviced. My shop has finally convinced me to go synthetic with all the fluids, better wear and cooler running temps, next time I will do the engine oil...............
 
Top