Knock sensor ? What is it ?

[D1CKY]

This may sound silly, but what is a knock sensor for ? :S

As i found my knock sensor whilst on the look out for my oil pressure sensor and oil level sensor http://www.cliosport.net/forum/showthread.php?t=322832

 

[col182]

senses knocks

 

[D1CKY]

Meaning ?

 

[Gumby]

... Who's there?

 

[D1CKY]

... Who's there?

Lol

 

[bmh.01]

It detects the specific vibrations given off by preignition ie detonation, pinking, knock etc.

Basically the fuel self combusting before its wanted to, the ecu monitors the sensor and adjusts various things (not sure 100% what) to stop it.

 

[mattjk]

Its like a little microphone I thought.

This is an interesting read

http://en.wikipedia.org/wiki/Engine_knocking

 

[ditz]

yeah basically a microphone, its a bit of a crude way of sensing pre ignition ie fuel igniting before the spark happens
caused by too much ignition advance, poor quality (or wrong octane rating fuel) too high a compression ratio/over boost etc etc,

it operates an ignition advance modifier in the map basically retards timing if it senses pinking to avoid engine melting scenarios

 

[D1CKY]

Ok cheers lads