Some 1986-87 models with 3.8L SFI, Roller Lifter Engines, built between start of production and mid-January, 1987, may exhibit an audible valve train rattle/lifter type noise on initial cold engine start up. The noise is audible only for a short time and diminishes with engine run time.
A midyear change was made to a .057" longer push rod. The longer push rod is identified with a red paint marking. Early production push rods had a blue paint marking.
While this condition may be an annoyance to the customer, engine durability is not affected.
When diagnosing this condition, make sure the original oil filter (black painted) has been replaced with a PF47 service oil filter, Part Number 25010792. If this condition is not corrected after using currently published diagnostic and service information, install twelve (12) longer push rods, Part Number 25532162.
Use applicable Labor Operation Number and times for push rod replacement.
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.