Just bought a 2002 Duramax with 97k on it. Had it about a week and noticed a rough idle and low oil pressure. Pulled it back in the drive way and crawled up under it. Soaked from front of the motor on the passanger side all the way to the tail pipe. Leak looks to have come from the blow by tube. Pulled dipstick and it smells like raw diesel. From everything I have read on here this is a sure fire sign that an injector has gone south. Planning on replacing all 8 while I am at it. Just wanted to make sure this is the only thing that would cause this before I put a big dent in the wallet.

 

you can always check the injector balance rates to make sure that its the injectors, sounds like it to me though

 

Any white smoke at idle or when driving? Go to the gm dealer and have them run the vin for service history... They had a longer warranty on the injectors and they might have been replaced once already (friend is on his 3rd set)

 

Thanks fellas, gonna try and get my hands on a Tech2 tomorrow so I can check the balance rates. Next question. Pretty sure I have lost most of my oil and mainly running on diesel fuel in the crankcase, do I need to drain it and refill with oil before I crank and run balance test? Also how much damage do you think has been done to the motor with fuel in the crankcase?

 

sounds like injectors and head gaskets

 

its just injectors, if you had the warranty still and drove it to the dealer with the crank case full of diesel fuel its an automatic injector swap.

 

It's injector issue mine did the same before replacing them.

 

oh yea, just did all 8 in mine and that is exactly what I experienced. Make sure to change that oil asap.

 

When you do a balance rate test what would be considered within spec?

 

+-4 in park, +- 6 gear at idle

All LB7 injector warranties are out of time now, GM wont replace any more injectors on LB7s for free