Thread: Pressure in motor - knocks when I shut it off

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Last time I shut it off, I stuck my ear on the side of the motor, since the engine
panel was off, and you can hear a knock, knock, knock sound. Like I said above, - - obviously nothing is moving, so I figured engine pressure, or pressure in engine from radiator? But the sound is coming from the engine, and not the
radiator. Could it be my aluminum heads cooling off quicker than the cast iron block?

I have had a motor so hot that it would make thunking sounds as the water boiled in the block. Is that sort of what it sounds like?

Not to be a smart-ass here, but are you sure the engine isn't still turning over with the key off? High comp engines will "diesel" for a while with no ignition sometimes, and make one hell of a knock.

Originally Posted by R Pope

Not to be a smart-ass here, but are you sure the engine isn't still turning over with the key off? High comp engines will "diesel" for a while with no ignition sometimes, and make one hell of a knock.

I'm the same way, R Pope. Mike, when you had your ear down by the block did you glance at the belts/pulleys and see that there was no rotation? Sounds like you're describing diesleling to me.