What Is A Knock Sensor

There are 3 Answers for "What Is A Knock Sensor"

1. skintknucles says:

   it is a sensor with a piezo electric generator that senses detonation {ping,spark knock } &retards ignition timing.
2. ErasmusBDragen says:

   it’s a piezoelectric sensor that is screwed into the engine block and detects if combustion is taking place before the pistons reach top dead center, which creates a knock. if knocking exists, the computer then retards ignition timing
3. SLamBob says:

   It is actually something like a microphone. The computer that controlls the engine listens for knocking and adjusts the ignition timing and other settings to avoid it.
   “knock” is also known as “ping”, “preignition”, “dieseling”, or “detonation”, and is generally the result of using gasoline with a lower octane rating than the car needs for best performance.
   If left unchecked, knock has the potential to damage an engine. Having the knock sensor allows the computer to adjust things and get rid of the knock, so instead of damage you just lose a little bit of power and get slightly worse fuel economy.
   Moving back to better gas will get the performance back.
   Now, if the sensor is worn out or damaged, the computer still wants to avoid knock so it will adjust to the safest settings it can, where it may not exactly run at its best.
   So, knock bad, sensor good.
   Check the owners manual for the recommended fuel grade.