Reference #: TRUCK 2002 11
Document Title: DIESEL FUEL ENTERING ENGINE CRANKCASE OIL (After Market Power Booster Kit) - TRUCK NOVEMBER 2002 - HIDL
Correction: Look for an after market power booster kit - 2001-02 Trucks with a 6.6L LB7 diesel engine
There are some cases where diesel fuel is getting in to the engine oil due to the addition of an after market power booster kit.
These power boosters raise the power by commanding additional fuel from the injection system. This additional fuel can not be consumed in the combustion process and the extra fuel is forced by the piston rings into the crankcase. This type of failure is not covered by warranty.
Make it a habit to look for after market equipment as a part of your regular diagnostic routine.
These devices, can be disconnected, very easily by the owner prior to bringing the truck in for service.
If an after market booster kit is installed to increase the engine power, what effect will that have on the transmission?
The transmission controls have been highly integrated with the LB7 Duramax diesel and the L18 gas engine in GM pickups. Part of this integration is that the TCM has a "map" of each engine's torque output throughout its operating RPM. The TCM uses "Shift Energy Management" (SEM). During most range shifts, there is more power available than necessary to perform the shift. The unused engine power traditionally goes into slipping clutches, and results in additional heat, gear and bearing loads without adding to vehicle performance. Through engine/transmission communication, SEM is the electronic control process that reduces torque during range upshifts to a level resulting in consistent transmission output torque before and after the shift. The net result is optimized shift quality as well as reduced clutch energy.