Questions and Answers

Pontiac Grand AM Speedometer Way Off Q. Hi I got a 1991 Pontiac Grand AM with the Quad4 engine and automatic transmission. I having trouble with the speedometer it is running about 45 mph fast at 55 miles an hour so when my Dads truck reads 55 mph mine reads 100 mph. I have put four new tires on, P195/70R14 it and have checked the gear in the transmission. It is the right color according to the GM parts guy. Any help would be great. Thank you, Jim

A. Is that the correct size tires for this car? Was the speedometer off before the tires were replaced? If so, you or the tire guy installed this problem somehow. If it was off before tires, it may be the Vehicle Speed Sensor (VSS) is skewed to the high side.