AboutCAJUNSC/RAMBLER390 Expertise 1998 and NEWER questions ONLY!! I WILL REJECT QUESTIONS FROM 1998 BACK. Electrical diagnosis. Brake Diagnosis. Driveability, Service Engine Soon Lights. Some Engine mechanical. Tires and wheels. ABS. HVAC. Air Bag (SIR). Interior, seats, etc... 6.6L Duramax Diesel diagnosis. 6.5L diesel diagnosis. I WILL not answer Alignment questions OR carburetor questions. No heavy internal transmission
I need YEAR, MAKE and MODEL of vehicle, and ENGINE SIZE and TRANSMISSION type, IF applicable to the question.
I work at a Large, Busy GM Dealership
Last thing, my answers are JUST SUGGESTIONS and ADVICE and you should ALWAYS CHECK with your mechanic for proper diagnosis and repair.
Experience 18 Years GM Dealership experience as an "A" line tech. ASE MasterTechnician. 100% GM paper certified and working towards MTC Certification.
Education/Credentials High School graduate. No College or higher learning.
Expert: CAJUNSC/RAMBLER390 Date: 1/19/2008 Subject: Duramax Smoking again
Question I have an 03 GMC Sierra with 6.6 Duramax. Injecters were replaced under warranty at 80k miles as engine would smoke espesially wlile ideling. Engine now has 125k miles and is smoking same as before. Dealer said injectors are fine and now the glow plugs and control module are bad. $840. later, the engine still smokes as before. Blue nasty stinking smoke. Truck runs fine and burns no oil.
Answer Hi
LB7 engine code I would HIGHLY suspect 1 of the injectors.
I have recently run into repalcing injectors and getting 1 or 2 bad replacement injectors.
Also if the copper seal was not installed, or it the hold down was not torqued.
They should be able to watch the balancing rates and pinpoint exact one. (-4 to +4mm3) is specs.
Anyone out of range should be HIGHLY suspected.
Have them check CAC (Cold Air Charger)blue tubes for proper
installation (maybe one fell off or backed off?)
For you I would check air filter. Replace if needed.
If you have an Oil charged air filter (K&N, etc...) they can cause similar problems.
I Hope this helps
Pawl
