what is a knock sensor

[poyter]

hey all i was just woundering what is a knock sensors is and what does it do?

[timbra_88]

A knock sensor is essentilly that. Its a small sensor which is actually a microphone which listens out for detonation (pinging), the sensor sends information to the engines computer and it will adjust the timing until the detonation stops. Detonation happens when the air/fuel combust before they're supposed to, which causes pinging.

[evlsky]

it in a prick of a spot on the v6's, its on the drivers side between the exhaust mainfold and power steering pump, need a china man with small hands to get to it, if it fails the motor wont rev out and will start to pinning/knock, happened to me!!!! over a 2k drive to get home, i melted the rings on 4 pistons and blew a head gasket

[delcowizzid]

motor wont ping if the sensor dies the ecu will pull as much timing as it can out to keep it safe boost on a stock tune is your issue

[VK SL 3800]

Thats surprising cause if it fails it should go into limp home mode and have a default advance for the entire rev range, could be wrong though.

[evlsky]

i wasnt running a stock memcal, was running a copy memcal tunned for burnouts i think, the memcal was orginaly done for a v6 supercharged corolla burnout machine.. no rev limiter. ran rich on idle.. the wire to the knock sensor broke off, i left work nailed it and the car only reved to 4 and half grand wouldnt go any further, i went to round up a friends vy 5.7 ute, so manual shifted it back, pulled past him and nailed it motor started to ping its head off wouldnt go any faster then 150k (i was on the freeway) limped her home, had oil all over the top of the motor, smoke pouring out of the dipstick, oil filler hole and inlet manifold, major misfire on 2 cylnders, pulled the motor down, blew the right bank head gasket, melted 2 3 4 6 rings and melted half the inlet manifold gasket on the left bank... only thing i could put it down to was that knock sensor, car ran fine when it was hooked up but died when the wire broke