This bulletin cancels and supersedes Dealer Technical Bulletin 88-T-119, which should be discarded.
Some customer comments may be received regarding excessive engine oil consumption. 'Excessive' oil consumption may be defined as approximately 1000 miles per quart or less. Light blue-colored exhaust smoke may or may not be evident in these cases due to the catalytic converter's exhaust gas processing. This oil consumption condition may be caused by one or more damaged intake valve stem seals.
An inspection of an intake valve stem seal from any cylinder will reveal if the seals are in fact damaged. The damaged seal(s) can be identified by a cutout section on the top portion of the seal, see the Illustration below. Valve spring removal is required to properly inspect the seal. If the seal is identified as damaged, all intake valve stem seals must be replaced with P/N 10042875 (currently available from GMSPO). Refer to Section 6A1 of the service manual for details on seal servicing.
If the intake valve stem seal inspection does not reveal any damaged seals, then the cause of the excessive oil consumption is in some other area of the engine.
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.