TrplBlk01

I heard little about it but what is it and what does it do?

C4 4Me

It listens for pinging and detonation and if any is detected the sensor reduces timing to combat it. I am not sure how bad the detonation has to be for a code to be tripped.

Also if you start your car with the temperature above 220 I believe the computer throws in a bunch of advanced timing to check the operation of the knock sensor. In other words it forces detonation to check it.

TrplBlk01

I do have a slight knock now... :mad

GlockLT4

You've confirmed this with a scan tool to see the timing change.. or you think you do because of a noise? Lots of noises come from these engines that can be mistaken for knock... like a lifter.. injector... exhaust leak.. all kinds of things.

When does it knock..? All the time, just under load, under acceleration.


[Modified by Glock'94, 2:51 PM 10/29/2001]

TrplBlk01

slightly at all times... :confused:

GlockLT4

hmm.. same kind of thing I'm getting... coule be a lifter.. or just the noisey injectors..

tempest

just another side note about knock sensors... the sensor does not directly sense knock, but it responds to vibrations in (usually) the cylinder block. this is why sometimes if you have a noisy injector or noisy valves, the knock sensor may pick up those noises thinking that it's knock. sometimes, even transmission noise can be picked up by the knock sensor.