For 1990-2009 cars

# GRINDING OR POPPING NOISE IN FRONT SUSPENSION

#### SUBJECT: GRINDING OR POPPING NOISE IN THE FRONT SUSPENSION/REPLACE COIL SPRING

#### VEHICLES AFFECTED: 1990-1991 C AND H MODELS

VEHICLES INVOLVED AND START OF PRODUCTION 1990 Pontiac Bonneville VIN L1253263 and higher 1990 Olds Delta 88 VIN L1830943 and higher 1991 Buick Park Avenue/Ultra Start of Production M1610700 1991 Pontiac - Start of Production M1200100 1991 Olds - Start of Production M1800100

#### CONDITION:

---------- Some owners of 1991 C and H models may comment about a grinding or popping sound from the front suspension when going over bumps. This contacting the upper spring seat.

To verify this condition:

1. Apply tracing powder to the second coil of the front springs on the wheel/tire side of the spring. The second coil can be identified as the first full coil that is approximately 25mm - 32mm (1 - 1-1/2") from the upper spring seat.

2. Run the suspension through its travel by pressing on the front bumper like you would to check for a bad shock absorber.

3. Inspect the tracing powder. Any contact should leave a witness mark on the coil.

4. To correct the condition, replace the coil spring affected. No attempt should be made to grind or bend the upper spring seat.

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.