Well with my problem...sounds just like a heat shield rattle for a couple seconds during a cold start up, it is not the clutch. I know this because it did it before I had my motor rebuilt and brand new clutch installed. It still does it after the new clutch and motor...starter problem sounds like a possible cause.

 

This does not cover all of you guys, but a cat shield will give a noise similar to what you are describing and is a common problem.

 

I think ssanto is right.
Mine makes the same noise on start up and I am positive its the starter cause my last car did that and that was the problem. The bendix is not fully retracting.

 

I've spent some time on this one, and I find that if I release the ignition a fraction earlier than normal, just when the engine catches, I don't get the rattle. This leads me to conclude that it is indeed the bendix sticking out longer than it should. I'll live with it until the starter packs it in.