A common issue with the GM 6.6L Duramax engine is white smoke at idle. Worn and damaged injectors are often the cause however there are other causes and considerations that should be looked at prior to injector replacement.
INJECTORS STUCK OPEN OR WITH EXCESSIVELY LEAKING NOZZLES DIANOSIS
1. Remove IGN 1 relay.
2. Remove the glow plug from the suspect cylinder(s).
3. Crank the engine and check for fuel spray coming out of the glow plug hole. Caution: Make sure you are not in front of