knock sensor

[Rivic]

can someone enlightin me on wot the knock sensor in ur car does? my engine light comes on and hooked a comp upto it andd the code its bringin up is knock sensor, mechanic said its no ergency not going to do anyhitng if the light comes on, its 230 bux to replace so can't just go buy one right now and there's no after market ones..

[jamchen]

i think it is something to detect petrol grade or something?
like if the car is designed run on 95 and you pure 92,, or something... correct me if i am wrong

[HondaTechy]

The Knock Sensor detects engine knock and sends a voltage signal to the ECM. The ECM uses the Knock Sensor signal to control timing. Engine knock occurs within a specific frequency range.
The knock sensor senses when fuel is burning unevenly and causing “knocking” or irregular vibrations in the engine. It consists of an electric coil that is wound around two ceramic rods with a magnet in the center. The vibration of the engine causes the rods to vibrate. This disturbs the coil’s magnetic field and alters the current passing through the coil. This disturbance returns to the computer as a signal pattern that the computer analyzes. The computer then determines whether the vibrations are characteristic of engine knocking.

[CRXer]

These sensors can be overly sensitive at times,so it could be a matter of no urgency,but if u dont know how to listen for knock(which can be virtually impossible at high rpms) then i suggest u just get it replaced as soon as money allows.

Also make sure your fuel system is clean,ie air filter, fuel filter & injectors,check your spark plugs & reset your ecu(i assume the mechanic already done this).If the code does not come back,then dont worry about it.

If it does come back,the knock sensor could be pulling loads of timing out of your engine for no reason & your car will be running shit,so that would be one good reason to get it fixed wouldnt it?

[Rivic]

thanx for the hlpe guys, car is fine atm only thingh i notice is when u come to a stop if the lights on it drops in rpm a heap then comes back up to normall. but will get replaced asap. is it jsut a sensor u take out and replace? where's it located?

[CRXer]

Its located under the intake manifold,just unclip the plug,unbolt it & replace, easy,just a bit of a bitch to get access to.