Can someone tell me what detonation sounds like. Does it sound like valves rattling or somewhat like a knock noise?

 

Depending on the severity of the detonation, it can sound like anything from a loud ticking sound, to a backfire but coming from the engine bay. I detonated alot on one of my old set ups due to a shitty fuel pump, and every time the cylenders would detonate, it would sound like a series of mild backfires, and the car would lose power..

Mike...

 

Metal Corns. Popping like popcorn.

 

shake some BB's in a soup can. otherwise.. tick tick tick tick tick tick tick tick