Hi again guys,
Turns out that the clanking noise I described in the previous thread on chain slap was coming from inside the right catalytic converter of my 380sl. It's particularly noticeable when I start the car on cold mornings, and dissipates shortly afterwards, as it warms up, for reasons I don't fully understand.
I had a custom mufffler shop put the cat -- - a Walker universal, I think -- on for me about 5 years ago, because the straight pipe system they had made for me was too loud. So, replacing the cat at this point should be fairly easy.
I suspect that something inside the cat, like a baffle, broke off, but why it stops shortly after the car starts running is a mystery. Has anybody seen this before, and does anyone happen to know who makes the best universal cat. At this point, I'm considering Goerlich. Magnaflow, Eastern, and D.E.C.
Thanks very much for any advice anyone can give me on cats, and for the previous responses.