My 1985 380SE seems to have this noise as well. It has the lifter "tick" or "chatter" when the engine is warm, especially on the passenger side, but also when driving, under acceleration- between 1500-1800 RPMS, there is a different noise- more like a knock that I can hear if the radio is off. I am assuming that my camshaft is worn as well, especially since the car has 268K.

I am wondering- will it damage the engine, continously driving it like this? I have owned mine for over a year and it has been doing this since I have bought it and it has not seemed to have become any worse.