The 1998 Cavalier came in four trim levels. In ascending order, they are: base, RS, LS and Z24. The three lowest trim levels came standard with a 115-horsepower 2.2-liter engine and the Z24 came standard 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 didnt 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.
2Crawl beneath the vehicle until you have a clear view of the rearmost part of the engine block.
3Look 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-liters sensor, but it is found where the transmission and engine meet.
Removing and Installing the Knock Sensor
- 4
Press and hold the unlocking button on the knock sensors wiring harness, and pull the harness from the knock sensor.
5Unscrew the knock sensor from the engine block with a ratchet and deep-well socket.
6Apply 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.
7Thread 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-liters knock sensor to 170 inch-pounds with an inch-pound torque wrench and deep-well socket.
8Plug the wiring harness into the new knock sensor.
9Raise the Cavalier off the jack stands with a floor jack and remove the jack stands. Lower the vehicle to the ground.