I was having issues with my regular cab for a long time. I took it into a diesel specialty shop and they found nothing. I only use for livestock and hay hauling. 75,700 miles. It would start heating 5 years ago on hot days with a full load. I would stop it. Past week it started drinking antifreeze. Verdict head gaskets and head work. $6500. I babied this truck and could never understand why this happened. I never let gauge get hot enough to bottom out or light to come on. My worry is how to prevent this? I never wanted to modify for horsepower because it is more then enough. I was looking at Thoroughbred Diesel website and called. They suggested aftermarket intercooler...Mishomoto radiator..and LBZ intake? I did the intake a year ago and it never made a difference. I almost traded it for a gas last summer and regret it now. I own it and don't want to buy a new pickup. What would you suggest with minimal investment to keep this from happening again. I always kept radiator clean. That is what I do with all my farm equipment? I am new to this forum and hope you guys can help me out with out too much crap.
2005 LLY overheated
- Thread starter Tull
- Start date
Shouldn't have to worry about the gasket, assuming you got a quality updated gasket set, and the mechanic's work is quality. The problem could have been fixed and addressed if Hg failure were the cause of your issue. In your case you possibly had a bad gasket, with no rhyme or reason just like with anything.
Head gaskets, studs, even a trans cooler wouldnr be a bad idea. I guess the factory gaskets for the lly werent very good from gm. So with an updated kit and good quality studs you should be fine. And as for the lbz mouthpiece (not the intake) it is nice make the turbo wake up and cuts lag. Thats what i felt it did for my lly. But if your happy with it then dont do it just re stud it and hg then be done with it.
Did the shop check the heads? I ALWAYS mill the heads and crack test them when doing HG.
You MUST do the WHOLE intake, not just the mouthpiece. The mouthpiece helps with the bottleneck at the turbo, but does nothing for the hot air getting sucked into the engine. So if you didn't do the whole intake and get the GM retune, you didn't do anything to help with your overheating. As to the intercooler and radiator, I wouldn't waste your money there. Too many have been having problems with mishimoto for me to roll the dice on them. You NEED to do a cold air intake like the LBZ or another one that sucks in cold air, not just from where the stock box did. When doing the LBZ intake, you need to follow the TSB and do all the baffles to keep hot air out. I do even more to open up the airbox to get more airflow through the fender, and I add in some more openings behind the headlight to get outside air in instead of air across the radiator. Replace your fan clutch with a KENNEDY unit. I had a brand new in the box HAYDEN fail on me with less than 1K miles after my 5 year old 60K mile one had failed just before. The factory clutches are good quality, but GM set the temps to high in them because of customers complaining about fan noise. I also like to block the EGR and do a basic tune to optimize timing instead of GM's emissions friendly tuning. Do some searches and you will find LLY overheating is not that all uncommon, but most have been able to be fixxed.
The new head gaskets should fix your gasket issue. Mine went over 10 years, 600 rwhp and 96k miles before they let loose. Those gaskets owed me nothing. As others mentioned the LLY mouth piece is a restriction, swap to the LBZ or a AFE mouth piece. The LBZ will require some adjustment to your intake system as it doesn't line up perfectly. The AFE is a direct swap. You can also add a supplemental radiator to the existing radiator. An oil cooler will help as well.
I can tell you with my truck, it has never overheated. It's pulled in 100*+ temps 12K pounds in the mountains of Idaho. The twin turbo's are what make the difference for me, lots of air to cool the engine down. I even ran twins with a stock trans and mild tune, I couldn't get the egts over 1200* ever.
I can tell you with my truck, it has never overheated. It's pulled in 100*+ temps 12K pounds in the mountains of Idaho. The twin turbo's are what make the difference for me, lots of air to cool the engine down. I even ran twins with a stock trans and mild tune, I couldn't get the egts over 1200* ever.
You said you hauled a lot of hay, have you checked/cleaned the cooling stack (radiator/intercooler/a/c condenser/trans cooler. You would be amazed at how much hay chaff and dust can get packed into the stack over the years.
