i have heard the word, and kinda know how to spot it by looking at the plugs. but what exactly is it anyway? and how can you tell your if you engine is dentonating by driving it? and is it the same a knocking or pinging? and if it is knocking or pining will you literaly hear a knock or a ping?

i know its a lot of questions but i am a bit confused and would like to finally clerify it...thanks for you help to those who respond.

 

To simply sum it up, detonation/preignition is the uncontrolled ignition of the air/fuel mixture during the compression stroke.

Pre-ignition is when a hot-spot within the combustion chamber ignites the air-fuel mixture before the spark plug fires.

Detonation is when a hot-spot within the combustion chamber ignites the air-fuel mixture after the spark plug fires.

Both rattle the piston and make a characteristic ping noise. It is in the 5-10 kilo-Hertz range or like a drum cymbal, but the ping noise happens very quickly. You should be able to hear it.

 

It's actually the pressure wave of the combustion beating on the piston BEFORE THE PISTON GETS CLOSE ENOUGH TO TOP DEAD CENTER, ie, it's trying to push the piston back down backwards, not good... That's why it is BAD news and can easily burn holes in pistons and/or blow head gaskets from the extreme pressures. and or crack heads.