Likely/hopefully just lifters. My '88 300TE (153k mi.) just went in for service, and lifters were diagnosed. Cam's fine, and typically is.
Allow me a rant; I'm not getting off so cheap, 'cuz my head gasket's begun to go! So, it's head gasket/guides/seals/water pump/hoses time; funny enough, it was also in to replace the radiator preventatively (it'd never been done, and it's of the old unreinforced plastic neck variety), and just that day it'd begun to leak!
Oh, well, I guess I had $2k burning a hole in my pocket (also re-did the wiring harness to the rear hatch...with 3 kids, we use it as much as the passenger door, if not more)...the price of keeping a car as-new.
But I'll never sell it! It goes to my seven year old
All the best, Michael