Mechanics

KNOCK UNIT

1997 Pontiac Grand Am

Engine Mechanical problem
1997 Pontiac Grand Am 6 cyl Front Wheel Drive Automatic 73246 miles

What is the purpose of a knock unit and what does it do does it pertain to the oil
Avatar
Debby1964
August 7, 2009.



If you are talking about a knock sensor? It screws into a water jacket and like a microphone listens for any pinging or pre-ignition. If it detects is it will tell PCM to retard timing anywhere from 1-15 degrees, to prevent damage to engine.

Mmprince4000
Aug 9, 2009.