GM Service Manual Online
For 1990-2009 cars only

DIESEL:POSSIBLE LOSS OF ENGINE OIL DUE TO PRESSURIZED CRANK

VEHICLES AFFECTED: 1982-85 G, P-2 With 6.2L Diesel Engines ----------------------------------------

A new crankcase depression regulator (CDR) valve is now available which aids in condensate drainback to the engine crankcase. The new CDR valve is designed so that the vent hose forms an angle towards the front of the engine.

This new valve, P/N 25095184, used in conjunction with the 1985 'G' and 'P' model's oil fill cap, P/N 25060118, prevents oil loss due to crankcase pressurization. The former valve and the vent hose could collect condensate and freeze at low ambient temperatures. This could cause the crankcase to pressurize, and a subsequent loss of engine oil.

The new CDR valve is available from GM Parts. This valve is interchangeable with the former one and is installed in the same location.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.