VIB. RUMBLE AND/OR SQUEALING AT OR JUST ABOVE IDLE

Model and Year: 1987-89 A CAR WITH 2.5L (VIN CODE R) ENGINE

TO: ALL CHEVROLET DEALERS

Some customers may experience a sound or "rumble" similar to that of a grounded-out exhaust pipe and/or squealing sound at, or just above idle.

The condition is generally limited to cars equipped with air conditioning and may be corrected by installing an improved tensioner assembly and the appropriate belt listed below. The repair procedure is detailed below:

Procedure:

1) Drain the coolant.

2) Remove the belt.

3) Remove the power steering pump assembly mount bolts and set aside.

4) Remove the existing tensioner assembly.

5) Clean the sealing surface on the cylinder block prior to installing the new tensioner.

6) Install a new tensioner assembly as follows:

1987 models without air conditioning - P/N 10066698 1988-89 models without air conditioning - P/N 10101362 1987-89 models with air conditioning - P/N 10101898

Torque bolts to 37 ft/lb (50 N.m.).

7) Install the power steering pump assembly. Torque bolts to 20 ft/lb (27 N.m.).

8) Install a new belt as follows:

Without air conditioning - P/N 10041195 With air conditioning - P/N 10101899

Parts are currently available from GMSPO.

IMPORTANT: Refer to Section 6B of the Service Manual for proper belt routing.

9) Refill coolant system.

10) Start the engine and check for proper operation and leaks.

Labor Operation Number: J0680 Labor Time: 0.6 Hrs.

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.