Hey fellas- my buddy has a 2004 Chevy 3500 with the allison auto and the Duramax engine. The truck is completely stock, but has been reflashed at the dealer once.

The problem is this. 20-25 times, while driving down the freeway, the truck starts to loose power, starts knocking/pinging (he says the motor feels like its going to come apart), and then starts emitting massive amounts of smoke. The smoke starts out black, then turns white. When this happens, he has no power, and he has been stranded on the road in the past. These issues also seem to correct themselves after 2-3 miles, which makes it hard to diagnose.

He has taken the truck in under warranty. The dealer is unable to find/duplicate the problem.I told him you guys would have probably heard of a similar situation, and might be able to help him out. Thanks in advance, Ryan

Start with a fresh fuel/air filter, and work from there.

Where are you located?

soot, first, Welcome.

I agree with Max, start with the basics first, but it sounds as if you have an injector hanging open. That will cause all of the symptoms your describing.

Where are you located?

L.A. County, in the valley.

Thanks for the help. He checked his fuel/air filters, thats not it. Im going to do a search on for injector issues, thanks. Ryan

Sounds like an injector.

socaldieseltech- I did a search and found the same problem listed in more than one thread.

Stanadyne has been been used since the first time the problem happened. This did not stop the problem.

The truck has 16000 miles on it.

Its been in the shop numerous times.

The dealer has a monitor installed on the truck, but what good will this do if no engine codes are thrown? No codes have been thrown thus far.

Can you tell me what your shop is doing when dealing with this issue?


Thanks, Ryan



*****on edit: the motor is an LLY, sorry for posting in the wrong forum*****