Do you have any history on the car, such as records, receipts, etc? If not, I would suggest adjusting the valves soon, or having them adjusted by your trusted tech. He can also check the timing chain stretch at that time. I would also change the motor oil and filter, and all other fluids (including brake fluid) and filters straight away, and start a new history. These engines are capable of very high mileage if well taken care of.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.