Occasionally, when I turn my car off, there's a knocking sound, fast at first and then 'winds down' until it goes away (probably 2-3 seconds). It sounds, and feels, like the engine is off.

I looked at this thread: https://www.crossfireforum.org/forum...ine-knock.html but didn't really find anything concrete.

Seems like it's only been doing it the past couple months, which I've replaced the ABS/ESP control modules, throttle body, and added a CAI. None of these seem like they would be the cause of the problem. I've changed the oil, using 0w-40 (8 quarts) and the correct WIX filter, but aside from that I have no idea what could be going on as I've not heard this in any of my other cars.

I'll try to get a sound file to post today or tomorrow, but until then, any ideas?