whats more common? wrist pin,rod,or bearing noise?

[Chambers]

My 7M-GE has a very similar sound, and my father took a listen and said its probably wrist pin knock. I'm not sure though, because I have put over 22K miles on and taken it to the track a few times and it hasn't blew up yet. Just this past October it blew the head gasket, I had the head re-furbished so I know its not the head making any noise because the tap that it did have has been resolved by a shim job.

On a couple occasions when I start it up, and while holding the clutch pedal down I hear a very audible scraping sound. I let the pedal up and the sound subsides, I push it back in and the sound returns. After one or two pumps the sound pretty much goes away for good. The clutch master cylinder is fine, fluid is topped off. I'm starting to think my pilot bearing is bad and has been like that for some time, and that has caused some ill effects on the clutch assembly and that's whats knocking. The only problem with that is that the sound appears as if its inside the block, about three cylinders back.

The first time my father listened, he used a makeshift stethoscope and heard the sound from the head. I have yet to stop by to have him give a listen since the head gasket repair though.

The 7M engines in general have a tendency to blow head gaskets and develop rod knock, but there is a distinct difference between the sound of rod knock and this mysterious knock in the 7M. I know this because my friends 7M-GTE just got a serious case of rod knock, it makes my knock seem like it supposed to be that way.

At any rate, keep us updated and I will as well. Good luck.