Duramax rough idle??? fuel treatment?

[oonighttrain]

lly injectors aren't covered for 7/200,000, it is the lb7 that's covered. Check the harness that goes over the altenator bracket for rub thru, repair as needed, then put a split piece of heater hose between harness & bracket. Also do icepick trick on # 2,& 7 injector clips, and replace fuel filter every 15 - 20,000 kms.

how many miles is 20,000 kms??

 

[B C]

If yours is an LLY, injector balance rates can show which injector may be bad; if that is the problem. Monitoring fuel return rates is GM's new way of detecting bad injectors on the LB7 motor.

 

[dangerfield]

how many miles is 20,000 kms??

Around 15,000 miles. Might not seem like many miles between changes, but it saves you alot of grief in the long run