Timing gears may wear causing a mild to severe knocking noise from the front of the engine. Replacement of the timing gears is necessary.
Average mileage: 146,000 (132,000–160,000)
Engines affected: 2.5L 4 Cylinder, 4.3L V6
8 people reported this problem
Pulled the S10 into the garage on a Friday.... everything was fin with the engine. Replaced the heater core and all four shocks. Started it up on Sunday to pull it out and engine was knocking severly at idle. Went for a ride around the block and noticed the knock fades at higher RPM. Ordered new timing gears