THE REAL STORY:

I have watched the whole video, and read all of TxChristophers posts on "The Diesel Spot" forums. He has a 2004 LLY Duramax that had the famous (to those who know) overheating problem common to 2004.5 and 2005 "LLY" Duramax trucks.

He sued GM over the issue, and it dragged on for a while. The video was made to be presented in court as evidence of the problem. GM had already installed a brand new engine in his truck, and installed their cure for overheating - the airbox assembly out of a 2006 LBZ truck. Neither helped. He was working with the new engine in the video.

He parked the UHaul on the trailer backwards, and chose a hot Texas day on purpose. He also chose the route on purpose. The truck was bone stock - in fact, the GM engineer that checked it after the install of the new engine and before TxChristopher got delivery of it, put security tape on the connectors to prevent "fiddling". While the dealer had his truck, the engineer also tampered with the hot engine alarm thresholds by raising them according to TxChristopher - which he warned them NOT to do.

He eventually was sucessful with his lawsuit with GM during the maditory pre-trial mediation/arbitration, and he was awarded ~$30,500 in loss of use and other damages, and allowed to keep the truck.

I don't agree 100% with his methods during taping, but I applaud him for taking a stand, hiring a lawyer, and going after what he deserved - compensation for an ill engineered product. He had a "partner" in the lawsuit with him - another LLY overheater owner, but that guy settled out of court for $6000 because he had a baby on the way and needed the money.

Someone already mentioned it, but I too was impressed with the ECM trying to save the Dmax from destroying itself. Killing the A/C, then cutting back fuel (which set the low fuel rail pressure code but did not illuminate the "Check Engine" light. He had the laptop connected to monitor the engine parameters for the video.

I am also a member over on the GM Duramax forum the DIESELPLACE. I lurk there every once in a while, and there are dozens and dozens of threads on LLY overheating. The consensus over there is that all LLYs will overheat (stock) given the right conditions which include heavy loads and hot weather. On a recent poll, 25% of LLY owners say their trucks have overheated. Notable though, is that some who say their trucks have not overheated say that they do not tow heavy loads with them, or say they pull over when the engine temp starts to climb to let the engine cool.

Perhaps the most interesting aspect of the story (to me anyway) was that TxChristopher is considering buying another GM Duramax truck! I gotta say, I'd be switching brands!

 

Yea there are no gaurantees no matter what brand you buy. My whole "agenda" against GM is their promise to make good an their errors of the past. First years are injector eaters and the follow-ons are overheaters.

 

does anyone else have any better ideas about why LLY's overheat? LB7' dont (but they have injector problems, so your darned if you have an LLY and your darned if you dont) overheat, so why?? Ive towed 10-12k on plenty of long hills, on that long uphill PA turnpike or whatever that long grade is. It was 95 degrees or so, hot OAT's. Mine didnt overheat with the stock turbo and it doesnt overheat with the new turbo. I really dont mean to start crap and Im sorry to anyone Ive offended, but is this stuff rocket scienece? Why is it proving to be THIS hard to find the definitive ROOT cause of LLY overheating. People say the cooling system is inadequate. I dont beleive thats completely true. Save for the turbo, EGR, injectors, FICM, and ECM, its the same engine as the LB7, which had no [overheating] issues.

People say that all LLY's can overheat, but I dont beleive thats true. GM is stupid about a lot of things and we can all argue theyve release some real pieces of junk over the years but honestly, do you think they would release something like the LLY if they experienced issues in testing identical to TxChristophers???

people argue about this till their faces turn blue, yet after all of this bickering we still cant say "x" IS the cause of LLY overheating. Im always amazed by the knowledge on all of these diesel forums combined, its mind boggling....youd think with all this combined brain power it would be simple to find out why..?

ben

 

I've read on the Diesel Place that part of the cause may be that the head castings were not proper and the restrict the flow of coolant and contribute to the OH problem. Whether it is true or not - I don't know. You'd think it would have to be something like that though for GM to continually deny the problem exists (so they don't have to fix it). If a simple procedure would fix it, you'd think they'd do it rather than have all the bad publicity.

 

Thanks Ben, I agree with you 100%

If everybody put their effort toward looking for answers instead of bashing each other, we would already know the answer.

Good stuff comes out of these threads when you guys discuss the issues, and THAT is what makes these forums interesting

Thanks guys for getting the thread back on track

 

The LLY's do have an overheating problem, however no truck is perfect. We have owned 2 dodges, an '03 2500 cummins and an '04 3500 cummins. Both have been a pain and expense. The Cummins has been good though. For us Dodge would be a 100% failure rate. Others have not had any major problems with theirs. I know I'll take some heat for this but check out this link of a newer Dodge that can't even make it up a snowy hill.

http://videos.streetfire.net/search/...9d38e57861.htm

 

Well for a moment I thought we were making some head way

 

THIS IS A RESPONSE FROM A GM OWNER ON THE DIESELPLACE.COM IN REFERENCE TO MY POST OF THIS VIDEO::::::"The video doesn't reflect an objective test comparison."

"That whiner should go and buy a Dodge. He didn't take any comparitive factors into consideration. True that a specific production run of Duramax LLY's did have heating issues, but they are limited to those runs, and effective remedies are available for cheap or free. Only a small % of that run had the problem, but we don't know why. None of the other models have this issue.

Comparitive factors:
He had no idea what he was competing with. A 90's Cummins can't compete with any Duramax, heat or no. The Dodge driver was probably wondering why he couldn't shake that Chevy after spending 8 grand on upgrades. Doubt he had his A/C on, but we'll never know.
The load he had was considerably heavier than what the Dodge was hauling.
The coach/jeep is much more aerodynamic than a backward-trailered U-haul truck. Huge factor at those speeds. Keystone Cougar trailers are lightweights.
His A/C was on from the start.

P0193??? Probably his fault (should have changed the fuel filter). This will very likely lose his case. Still, limp mode is better than dead in traffic.

He may have a valid claim for his issues, but he needs to compare apples to apples if he wants to use it as a factor of argument.

If your first choice is Cummins, stay with it. Not likely you'll be happy with anything else. If you want a GM product, don't get an LLY and you'll sleep better. You won't shake that video, and will be looking for flaws.

You brought your question to a GM Diesel enthusiest website. Expect some bias. You'll get the same at the other sites, but probably worse than you'll find here. Brand loyalty here usually doesn't cross into ignorance."

 

$8,000 on upgrades for a 24 valve to shake a stock LLY Duramax.

No ignorance there!!!

Anyways, other then that statement, he is perfectly correct...

 

Um, that's just barking the turbo, most trucks will do it if you let off the throttle real fast, that's all I can see.

 

I agree 100% that the D-Max in the video should not have been overheating if stock, and nothing mechanically wrong with it. However it was probably pulling around 4000 lbs. more than the Dodge, and with a whole lot more wind load because of how the U-Haul truck was loaded. That trailer looks like the one Big-Tex rents, and it is very heavy (5500 lbs.) empty, I have rented one just like it from them before. I would guess the U-Haul weighs 8500 lbs. for a total of 14,000 lbs. and again don't forget the wind load of that truck being loaded backwards. I'm sure that was done to make things look even worse for the D-Max. Isn't 14K or less the maximum towing capacity for that truck anyway? I also think it's kinda convenient a Dodge pulling a trailer, and a jeep ( probably 10K total and much more aerodynamic ) just happens to appear for comparison. I know if I were in Dodge I would have got tired of that clown plugging the hammer lane and left him way behind long before that video ended. They don't make a zoom lens strong enough that would have allowed him to keep taping. Did anyone else notice the 19 mile range left showing on the dash at the end of the video. The low rail pressure at the end might have been because it was about out of fuel. The whole thing reminds me of one of those supposedly caught on tape funniest videos. Maybe he forgot to take the cardboard out from the front of the radiator when winter was over. LOL

 

exactly!!

I definetly could not have said htat better myself

ben

 

Fine, take the Dodge out of the video and strike all of the Dodge comments the guy made in the video from the record.

What are you left with?

The facts are there whether you believe this particular video or not. No one is denying that there are a batch of overheaters out there. This guy had another engine installed and it still did it. Do you think GM would install another bad engine on purpose? Wouldn't it possibly have been from a different batch? If the heads had casting issues than why doesn't every single LLY overheat?

My guess is yes, something is wrong either in the design or a bad component that puts the truck on the threshold of overheating. Some do because they do things that take it past the threshold. I feel bad for anyone that gets one of those trucks and actually uses it in extreme conditions.

Maybe it's all of GM cushy gadgets and attention to comfort that diverted their attention from the real reason for a diesel.

 

Three reasons I can think of:

1. EGR system returning hot exhaust gasses right back into the intake without cooling it down first
2. Stock air box takes hot air from the engine compartment instead of from an ambient source
3. Poorly designed stack/grill, and radiator not big enough

The LLY was probably originally designed to take intake air from the fender - there's a hole right there next to the air box. But for some reason Chevy closed it up, and made the air box suck it through the hot engine compartment.

I know this will probably cause some controversy from those here who run the BHAF.

 

No, you're right: generally speaking, engine compartment ambient temperatures are high enough to cause/aggravate issues like this, but the Rams (3rd gen especially) have an advantage due to the large amount of free space underhood and the ability to direct fresh air in around the radiator, CAC, AC condenser, PS cooler, etc.

My Super BHAF draws air from just under the hood (unless the cowl induction hat is installed), and the differential stays well under 25*F unless I'm on the dyno.

Of course, the Cummins is the King of Cooling...