GM Service Manual Online
For 1990-2009 cars

INFO ON TIRE FLAT-SPOTTING BALANCING WILL NOT CORRECT

SUBJECT: Information on Tire Flat-Spotting

MODELS AFFECTED: All Saturns

CONDITION:

Some customers may comment on vehicle vibrations at highway speeds of 72-85 Km/h (45-55 mph). This vibration is apparent after the vehicle has been parked and disappears while driving.

CAUSE:

The vehicle's vibration may be caused by "Tire Flat-Spotting." Tire flat-spotting is a temporary condition caused by the rubber in the tire, and other internal components, flattening out during extended parking (usually 24 hours or greater). Flat-spotting can occur on one or more of the vehicle's tires.

Most standard automotive tires will flat-spot under the above conditions. The degree of the Rat-spotting and subsequent vehicle vibration varies depending on tire design, road surface, temperature, etc.

Driving the vehicle eliminates the flat-spot. However, the number of miles required to eliminate the flat-spot is dependent on the length of time the vehicle was parked under the above conditions and the ambient temperature during driving.

NOTE: Balancing tires will not eliminate the vibration caused by tire flat-spotting.

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.