1991 GMC Sonoma Problems

RepairPal has identified the most common problems with the 1991 GMC Sonoma as reported by actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.

Refine by vehicle
×
Choose your vehicle
18
Known Problems

The spark plug wire rubber boots may get soaked with oil, causing a misfire or rough idle.

The Anti-lock brake system (ABS) control unit may fail internally causing the ABS warning light to illuminate.

An engine oil leak may develop from the distributor shaft o-ring seal.

The distributor may develop internal faults. This can cause a rough running engine or stalling condition and the Check Engine Light may or may not illuminate. The distributor should be overhauled or replaced to correct this concern.

The fuel pump may fail causing the engine to stall and not restart. Our technicians recommend replacing the fuel filter every 30,000 miles to help prevent undue strain on the fuel pump.

The electrical contacts in the ignition switch may fail and result in erratic instrument panel gauge operation or illumination of the Check Engine Light. A failed ignition switch will require replacement.

The heater core under the right side of the dashboard may leak engine coolant which can puddle on the passenger front floor. The loss of coolant may cause an engine overheating condition. Our technicians tell us that removal of the dash board is necessary to replace the heater on these vehicles.

The oxygen sensor can fail causing Check Engine Light illumination and the engine to run rich (burn more fuel than normal).

A door window may move slowly or stop in mid travel due to a failing power window motor. The affected window may start working again after the motor cools off. Replacing the faulty window motor will commonly correct this concern.

The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.

Our technicians highly recommend that the transmission is serviced every 30,000 miles to avoid problems and maintain optimal operating order.

A coolant leak may develop from the water pump. This can result in an engine overheating condition. A leaking water pump will require replacement.

The alternator may fail, causing a "no charge" condition. An internal bearing may also fail and cause an abnormal noise. If the vehicle is driven too long with a failed bearing, the alternator may stop turning, which can cause the serpentine belt to break or the engine to stall and not turn over.

This engine may leak oil from the valve cover gasket.

Brake fluid can become dirty and may cause problems in the brake system; it should be flushed every 60,000 miles.