I have an LLY Duramax, 04.5 model year, and a Friend of mine has one also. We both tow large 5th wheels (13,500 lb, gross) and neither one will overheat, even when the temp is 95 plus.
I am sure that if we tried to maintain 70 mph on a 6-7 percent upgrade we could MAKE them overheat, but why try?
I have efforted to leave personal agenda out of this thread, notice, no signature, no ambition except to help people not get taken, and to expose this problem more for what it is, rather than for what it has been hyped as (lies). But it leaks out obviously.
LLY is not an overheat issue. It is an all-inclusive performance issue, only one symptom of which, is the potential for load induced overheat. Those that have owned the earlier LB7 and the later LBZ, realize that the sandwiched LLY got shorted in several respects: Economy, Power, and Thermal Buildup. The one that got the most attention is the thermal heatsoak...
It has gotten the attention of many engineers, GM corporate, the Hot Weather Test facility (nearby), and especially one supplier: Garrett, who has been in the loop all along. The LLY has gone through significantly more turbocharger warranty claims than any other model, mainly from those who pull hard in mountainous elevations.
Up to 2 mpg, 10% of the total fuel burn is combusted in trying to compensate for this issue, hence the lousy economy "performance" and mpg complaints.
If people see what happens with the "whole performance" of the vehicle when this issue is addressed, they get an education, instead of a band-aid. A fellow Canadian verified much of this in a MaxxTorque article last month. That would be a good place to start.
Anyway, my feathers are intact, I am sad that video is still making the circuit, because it represents, at best, a spook film IMO, exactly typical of how you scare the whole world, then invite everyone to eat from your plate.
a sales tool...for the neurologically challenged and criminally arrogant. Ask me what i really think. At least everyone now knows how not to tow a U-haul with a light duty truck.
But remember, I mentioned no names.
* This post was
edited 08/17/08 09:26pm by killerbee *
I would also check out dieselplace.com and look around there...Its about the D-max...
Also some will say the lly is an overheater, but I know I heard before its one out of 600 trucks, so????
Anyways, my opinion is I would get an
2006 LBZ duramax...
2007 GMC DURAMAX,LBZ,4 by Crew, Allison
Magnaflow Turbo Back Exhaust
Predator Tuner
18by9 Helo's on BFG's
5year old boy
3 year old baby girl
Sea ray boat
Wilderness 5th wheel
SandRail
HD WideGlide
FORD Expediton
honda Eu3000
Contrary to the thought that you must heavily load the vehicle or drive it through death valley to get it to overheat:
"I have a 2005 duramax duelly. I have had it overheat pulling a 3000lb trailer when it was 75 degrees outside. I have it overheat unloaded and no trailer at 95 degree temp. The cooling fan starts to roar and the temp gauge keeps climbing untill the dic starts to flash coolant hot. Took to dealer on several occasions they changed the cooling fan assembly 2 times and then changed out the air cleaner assembly from a 2006 lmn but my truck will still overheat and sound like a SCHOOL BUS. I also have a problem with the steering issues. Namely the hard stiff steering at slow parking lot speeds and or when the truck is stopped and try to turn the steering wheel. It turns ok for about half of the wheel travel then it gets so stiff and looses power assist. I have had a new power steering pump installed, new steering gear assembly and was also told on one occasion that one of my tires was a few lbs to low on air that was causing me troubles. Imagine that on a $51000 truck that starting haveing these issues at 1613 miles.. The truck now has 21000 miles on it and I am afraid to use it anymore because I dont want to jeopardize my familys lives driving something that could leave us stranded on the side of the road somewhere. Gm states it can not duplicate some of the problems but the mechanics pull me to the side and say there are a (lot of complaints) about the same problems Iam having.
The truck is a 3500 hd DRW 4x4 with all the heavy duty towing packages and coolers.
I am hoping someone on here would have some suggestions as the truck now just sits in my garage unused.
ib516 wrote: Contrary to the thought that you must heavily load the vehicle or drive it through death valley to get it to overheat:
"I have a 2005 duramax duelly. I have had it overheat pulling a 3000lb trailer when it was 75 degrees outside. I have it overheat unloaded and no trailer at 95 degree temp. The cooling fan starts to roar and the temp gauge keeps climbing untill the dic starts to flash coolant hot. Took to dealer on several occasions they changed the cooling fan assembly 2 times and then changed out the air cleaner assembly from a 2006 lmn but my truck will still overheat and sound like a SCHOOL BUS..........
Now you claim to have no agenda with posting the silly video link, so then what is the purpose of this post? His truck CLEARLY has problems that have nothing to do with the claimed typical LLY overheating.
I should also point out in my web wanderings the trailer in that video caused such wind resistance/drag that the truck could ONLY run ~75 mph (give or take, its been a while) on the flats to begin with. So what I see in the video is a light duty diesel with an automatic transmission being run indefinitely at 100%.......on the flats.......I thought it performed pretty well.
Thanks everyone for your input. I had no idea that the "overheat" issue is such a hot button.
BTW, I am still not too comfortable with the #2 item of my earlier list:
Quote: (2) During the test drive, I gently increased the foot pressure on the gas pedal when going up a small hill but did not feel much response. (I had never driven a diesel before this and was expecting a big powerful surge when I stepped on the gas). The dealer told me that this truck has a diesel turbo engine and I have to press hard on the pedal (flooring it) using a steady and even pressure. He later demonstrated this to me and the truck indeed shot up the small hill very fast. Is this normal with the turbo diesel or should I be concerned that there might be some kind of problem with the engine?
Here's another piece of information that had puzzled me. After we got back to the dealership, I asked the dealer to let me drive a new 08 diesel Silverado 2500 for comparison. When I pressed the pedal in the same way on the same section of the road, I felt a strong surge of power without "flooring" the gas pedal. The sales person explained to me that because "the 08 truck is only a diesel, not a turbo diesel, it thus responded quicker". Huh? Any additional comments on this are truly appreciated.
ib516 wrote: Contrary to the thought that you must heavily load the vehicle or drive it through death valley to get it to overheat:
"I have a 2005 duramax duelly. I have had it overheat pulling a 3000lb trailer when it was 75 degrees outside. I have it overheat unloaded and no trailer at 95 degree temp. The cooling fan starts to roar and the temp gauge keeps climbing untill the dic starts to flash coolant hot. Took to dealer on several occasions they changed the cooling fan assembly 2 times and then changed out the air cleaner assembly from a 2006 lmn but my truck will still overheat and sound like a SCHOOL BUS..........
Now you claim to have no agenda with posting the silly video link, so then what is the purpose of this post? His truck CLEARLY has problems that have nothing to do with the claimed typical LLY overheating.
I should also point out in my web wanderings the trailer in that video caused such wind resistance/drag that the truck could ONLY run ~75 mph (give or take, its been a while) on the flats to begin with. So what I see in the video is a light duty diesel with an automatic transmission being run indefinitely at 100%.......on the flats.......I thought it performed pretty well.
I certainly have no agenda, and I don't see anything "silly" about a video link that was used in a lawsuit concerning exactly what is being discussed. I'm sorry you don't like the content. Whether or not that particluar posters truck "has problems" is up to the person that reads what he posted to decide. I certainly am not "vouching for him", don't even know the guy.
Not intended to be, nor should what I posted be taken as anything personal, it's just a hunk of metal after all.
I just call 'em as I see 'em.
In fact, a close friend of mine at work used his fathers combo of a 2005 2500HD Chev and fifth wheel last summer. He weighed in (CAT Scale) at exactly 20,000# GCW. He towed through the Canadian Rockies with a lot of cooling fan (almost on as much as off acoording to him), but no overheating or "engine coolant hot" messages. To be honest, I was surprised. But, it is the truth. Seems there is varying degrees of issues that cover the whole spectrum. Some overheat easily, some have never overheated.
Anyway, the whole point was for the OP to be aware of the possibility of a problem. That is what this forum is for isn't it?
If someone comes here seeking information, then that is what I'll give, if I have it, or know where to find it.
I posted the second link as I thought it added to the information, nothing more, nothing less.
I certainly have no agenda, and I don't see anything "silly" about a video link that was used in a lawsuit concerning exactly what is being discussed. I'm sorry you don't like the content. Whether or not that particluar posters truck "has problems" is up to the person that reads what he posted to decide. I certainly am not "vouching for him", don't even know the guy.
Not intended to be, nor should what I posted be taken as anything personal, it's just a hunk of metal after all.
I just call 'em as I see 'em.
In fact, a close friend of mine at work used his fathers combo of a 2005 2500HD Chev and fifth wheel last summer. He weighed in (CAT Scale) at exactly 20,000# GCW. He towed through the Canadian Rockies with a lot of cooling fan (almost on as much as off acoording to him), but no overheating or "engine coolant hot" messages. To be honest, I was surprised. But, it is the truth. Seems there is varying degrees of issues that cover the whole spectrum. Some overheat easily, some have never overheated.
Anyway, the whole point was for the OP to be aware of the possibility of a problem. That is what this forum is for isn't it?
If someone comes here seeking information, then that is what I'll give, if I have it, or know where to find it.
I posted the second link as I thought it added to the information, nothing more, nothing less.
Fair enough. I took nothing personal, and my take on the silly video was simply for perspective for someone (not you) unfamiliar with trucks in general.
Yes the point is an exchange of info. On that point I would probably pass on the 05, an 06 could be found for similar money and IIRC has the manual shift mode on the Allison.
I have not been too particularly fond of the Allison (I always swore I would never own another auto tranny to tow with), I have an 04. I cant imagine owning an earlier model that was unable to lock out 5th range. This grade braking thing is rarely in the gear I would select, usually waiting too long to shift down, then shifting down 2 gears. I end up selecting my own gears anyway, or fighting the brake and fuel pedal to get in the right one. It has been suggested my truck needs to "relearn", I dont know. Probably not worth my time. I am no doubt in the minority here, so I generally dont 'exchange' this info with prospective Dmax/Ally shoppers. Although most who want an auto dont know/care how to shift their own anyway.
"The truck is a 3500 hd DRW 4x4 with all the heavy duty towing packages and coolers.
I am hoping someone on here would have some suggestions as the truck now just sits in my garage unused.
thanks for any help,
David"
I know what you can do, sell it to me for a good price. That would be better than just leaving it sit there.
2006 GMC Sierra SLT 2500HD crew cab 8.1 with 6 speed allison
2007 Keystone Laredo 32rs
Myself, Darling wife Lisa
Laura 16,Sara 13
2 Jack Russell's
Jack & Rusty
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At least everyone now knows how not to tow a U-haul with a light duty truck.
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