you might want to make your own thread if u want helpful replies. (also this thread is old as  and not relevant to your problem.I have a 2000 Focus ZX3 and when i start it the motor rattles almost like its knocking, kinda like rocks in a coffee can. It goes away after a few sec. or if i rev to about 1600 rpm it stops the rattle faster. Also when i give it gas out of gear it does it agin right before idle falls back down to 600-1000 rpm. Anybody have any clues on whats going on? I hope its not the lower bearing. I listened under the hood with a screwdriver to my ear and didnt really sound like it was from the internal parts of the motor. Do hear it more on the headers but everything is tight to my eye.