A Prevous thread mentioned exhaust hanger as source. My noise sounds somewhat metallic (clanging?)to me as well. Thought may be cracked/loose flex plate but as only seems loudest at cold startup not sure. Always there but at much less volume as car warms to operating temp. Then it seems intermittent but i can still hear it but not constant.Thought maybe piston slap but too metalic in nature I believe and not constant enough. 77 300d milage unknown. Not pumping oil, great oil pressure hot, seems to have pretty good compression. I am not really lazy or familar enough yet with this particular series. Just hoping to save a little time and open to suggestions. Have not really looked at anything yet except exhaust hanger and it's solid. Noise does not seem to be getting particularily worst with time.