GM Service Manual Online
For 1990-2009 cars only

SERVICE GUILD: MILKY DEPOSITS IN CRANKCASE

MODELS AFFECTED: 1988-1989 SKYLARKS WITH 2.3L (VIN CODE D)

In cold weather, repeated short trips with limited engine warm-up may allow moisture to accumulate in the engine oil. This can cause milky deposits to form on internal engine surfaces, and may be visible on the oil dipstick. Driving the vehicle for at least 20 minutes dissolves the deposits, evaporates the moisture, allowing their removal through the engine vent system. If these conditions persist, the engine oil should be changed at 3000 miles or as indicated by the Engine Oil Change Indicator. This condition is not uncommon in other internal combustion engines.

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.