This bulletin cancels and supersedes bulletin 88-6-91A issued 3189 and 88-6-85 issued 12188. Please discard these two bulletins.
CONDITION: Some owners of the above vehicles may comment on a puff of blue or bluish white tailpipe smoke on startup.
CAUSE: Oil leaking past valve stem seals and being deposited on exhaust valve (s) .
CORRECTION: A new valve stem seal kit (P/N 12511890) has been released to address this concern. The kit incorporates a new umbrella seal with a "viton" insert for the exhaust valve stem.
Parts are currently available from GMSPO. Use applicable Labor Operations and Times.
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.