How to Remove the Knock Sensor From the Engine Block of an Astro

The knock sensor mounted to the engine of a Chevrolet Astro is there to determine if the engine is knocking--a condition that happens when the timing of the engine is off. The sensor tells the computer to adjust the timing accordingly to stop the knocking condition. These sensors can go out over time, and if they do, then the engine can knock unchecked. If that happens, you can lose horsepower as well as potentially damage the engine itself.

Things You'll Need

• Open-end wrench set

Instructions

1. Remove the doghouse cover from the inside of the vehicle by pulling up the tabs at the base of the cover, then lifting it up and away to reveal the back side of the engine.

2. Locate the knock sensor on the engine, which is either on the back of the driver's-side cylinder head, on the side of the driver's-side cylinder head between the pipes on the exhaust manifold, or just behind the distributor. Unplug the electrical connection on the knock sensor using your hands.

3. Remove the sensor from the block using an open-end wrench.

References

• "Chilton's General Motors Astro/Safari 1985-96 Repair Manual"; Ben Greisler; 1997