The 1998 Cavalier came in four trim levels. In ascending trail, they are: example, RS, LS and Z24. The three lowest trim levels came sample with a 115-horsepower 2.2-liter engine and the Z24 came criterion with a 150-horsepower, 2.4-liter engine. The 2.4-liter engine was an option for the LS trim level as well. Both engines came fitted with a knock sensor, which detects vibrations in the engine caused by spark knock. As the level of vibration increases, so does the voltage it sends to the computer. According to this voltage signal, the powertrain control module retards the ignition timing to eliminate the knock. Chevy didn't hide the knock sensor on the 1998 Cavalier, but it is tough to find if you do not know where to look.
Instructions
Locating the Knock Sensor
1. Raise the front of the Cavalier with a floor jack and slide jack stands under its subframe.
2. Crawl beneath the vehicle until you have a clear view of the rearmost part of the engine block.
3. Press and hold the unlocking button on the knock sensor's wiring harness, and pull the harness from the knock sensor.5. Unscrew the knock sensor from the engine block with a ratchet and deep-well socket.6.
Look to the left of the oil filter on the 2.2-liter engine and find the knock sensor, the circular electrical component connected to the engine block. On the 2.4-liter engine, the knock sensor is on the rear of the engine block and looks the same as the 2.2-liter's sensor, but it is found where the transmission and engine meet.
Removing and Installing the Knock Sensor
4.Apply a thin coat of a thread-sealing chemical to the knock sensor if the new knock sensor does not already have thread sealer on it. Allow the sealer to cure for the time specified by its instructions, which typically is less than five minutes.
7. Thread the new knock sensor into the engine block by hand, then tighten it to between 12 and 16 foot-pounds on the 2.2-liter engine with a torque wrench and deep-well socket. Tighten the 2.4-liter's knock sensor to 170 inch-pounds with an inch-pound torque wrench and deep-well socket.
8. Plug the wiring harness into the new knock sensor.
9. Raise the Cavalier off the jack stands with a floor jack and remove the jack stands. Lower the vehicle to the ground.
