The S-10 Blazer arrived in Chevrolet's lineup in 1983, as the mid-sized complement to the existing full-sized Blazer. The 1999 Blazer -- Chevy dropped the "S-10" moniker in 1995 -- came standard with a 4.3-liter V-6 that produced 190 horsepower. This engine had a piezoelectric component that detected abnormal engine vibrations, such as spark knocks, and sent that information to the knock sensor module in the powertrain control module. The PCM then retarded the Blazer's ignition timing until the knock stopped. When this sensor fails, you must replace it, as the computer cannot detect and compensate for potential damage-causing engine knock.
Instructions
- 1
Find the Blazer's knock sensor on the driver's side rear of the engine, just behind the valve cover. Press the locking tab on the knock sensor wiring harness and pull upward on the wiring harness to unplug it.
2Remove the knock sensor, using a ratchet and socket.
3Coat the threads on the new knock sensor with water-based caulk. Hand-tighten the knock sensor into the engine and apply 14 foot-pounds of torque, using a torque wrench and socket.
4Press the wiring onto the top of the knock sensor and press it down until it clicks into place.
