6.6 Duramax Excessive White Smoke


Problem: Injector issue


The LB7 trucks have had many injector problems, to the point where GM increased their warranty to 7 year/200k miles. What starts as a wisp of white smoke on start-up can slowly progress into a larger issue. An injector issue can also manifest itself in the truck “making oil”, meaning the oil level raises over the life of the oil. This is from excess fuel dripping out of the injectors, past the piston rings, and into the crankcase.
Even though the redesign of the injectors in 2005 was an improvement, the injectors can still fail and will have the same symptoms. The service manual fix is to replace all 8 injectors. Before you take the truck to a mechanic, try Diesel Extreme. Treat one full tank (or two tanks, if necessary) to clean out your old injectors.

In a high-pressure, common-rail fuel system, the only thing lubricating the internal parts of the injector is the fuel flowing through it. One of the major factors in the failure of injectors is that there is not enough lubrication in the fuel. As a preventative measure, use our Every Day Diesel Treatment to lubricate your fuel system.

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