LLY Turbo Issues??

[MPH]

Was driving down the road today, when it felt like my truck just fell on its face. It would accelerate fine up to about 3/4 throttle, then nothing. Sixty was as fast as it would go giving it more throttle would kick the transmission down and bring the rpm's up but it would not accelerate. Anyway, took it straight to the dealer, they checked the codes, and are telling me that it has something to do with the turbo, i saw the screen, and it said something about engine underboost. They said the computer gave them nine pages of stuff to diagnose, and they still haven't figured it out.
Has anyone had any exeperience with this or have any ideas what it could be? The truck only has 900 miles on it and i am wondering if i got a lemon. Sorry this got so long, any help would be appreciated. Thanks.

[Madd Max]

I had a similar incident happen to me at about 12k. It would bog down when I mashed the accelerator and a lot of smoke. This happened while towing my trailer. When I let off the pedal a little it would pick right up, push hard on the pedal it would bog back down. Max speed on a flat was about 65. Took it in they diagnosed it in about 8hrs. It was the variable turbo vane positioning sensor, they had to send for a new sensor took 2 days, I got it back has run great ever since. I might just be me but it seemed louder after the fix. This is the only problem I have had. 16k on her now. Hope this helps.
Truck was stock when this happened.

Dennis




this

[HELENA TRANSMISSION]

my brother has a 05 900miles.same problem turbo vane sensor.had to rob one of another truck to get his going.also had a transmission cooler line leak.

[MPH]

Got the truck back today. They told me that everything was fine, the only thing they could come up with was to tell me that it was an intake or exhaust restriction that caused the truck to throw the code. Anyways, they cleared the code, and the truck runs fine for now. I am a little skeptical though.

[sycamore]

I had a similar problem a few months ago, the turbo vane selinoid and sensor were replaced,It took 3 weeks to get the parts. Then a few weeks later ago a SES light. Took to the dealer no codes, but the tech called GM Engineering and they said to replace the turbo, they ordered the turbo and of couse the turbo was on national backorder. Well the turbo came in a week later, and they forgot to order the gaskets, after I was assured thay had everything they need. Well guess what, the gaskets are on backorder now. I should add that the part # for the LLY turbo has been changed, so case in point there seems to be some turbo issues. Also parts all have to come the source GM does not stock much of anything for these engines. Parts availability seems to be an issue. While this whole fiasco is going on I still are getting SES lights, When it appear you can tell, the truck has a lot of turbo lag. Everytime I get a light I scan it but no codes, then the light dissapears and the truck will run fine.
Well finally I went to dealer today to price a 2005 and said there is a material constraints on the Duramax engine,parts issues again. After 5 years you would think GM could get it right. Very discouraging to say the least. :rolleyes: :rolleyes:

[sycamore]

Well the dealer replaced the turbo today, actually it took 1.5 days, the tech said it was real bear to change,seems seems to run well, the large amount of turbo lag is now gone, the decision to replace the turbo came directly from GM engineeing, I was getting a low\high boost trouble code, I will keep you posted. Also I should mention the turbo vane selinoid and turbo vane sensor were replaced when the truck was about 1 month old. :eek: :eek: