Timing gears can cause knocking sound on Chevrolet S10

Problem Description and Possible Solution
Timing gears may wear causing a mild to severe knocking noise from the front of the engine. Replacement of the timing gears is necessary.
Problem Data
RepairPal Verified
Average mileage: 146,000 (132,000–160,000)
Engines affected: 2.5L 4 Cylinder, 4.3L V6
4 model years affected: 1990, 1991, 1992, 1993
8 people reported this problem
Viewing 1 - 3 of 3 comments
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
I have a loud knock sound from the front of the motor. I have a 2.2 lit 4 cylinder. The sound changes pitch when I read the motor up and down