[RSRXION]

Detonation is most likely a direct result of too much advanced timing. Also known as spark knock or pinging it can also be caused by extreme heat during heavy towing operations , low grade fuel or summer driving conditions.

Detonation is sometimes accompanied by a couple of other undesirable behaviors like difficulty starting the engine when it's warm and engine run on after the key is shut off. These behaviors are not always present in an advanced timing situation but they are good indicators of the cause.

Fix the problem as soon as you can. Detonation is murder to the valvetrain of any engine and will surely do harm. The valve seats will be the most likely victim but valve stem/head failure or piston damage will follow closely behind. I don't need to tell you what will happen if you drop a valve head or burn a piston. It's nearly always a bad sign when small parts of metal start bouncing around inside your engine.

Good luck, Dean