Can someone tell me how the knock sensor works?? Espically in the coolant?? Thanks in Advance

Brad

 

It is basically a little microphone. It has nothing to do with coolant as such. Spark knock sounds like hitting the block with a hammer; the knock sensor is "tuned" to pick up the particular range of frequencies that are produced which varies with bore size. It would work the same no matter where on the block it is installed, the coolant drain hole was just a convenient place for the factory to stick it without having to change the casting or anything expensive like that.