My euro model 500SL makes a slight knocking sound on start up, some times. It goes away very quickly and does not come back. This seems to happen only some of the time, and it does not matter how long the car sits. I just changed the oil after about 800-1000 miles, and I used 10W-40 max life with new MB filter. No change. what could this be?

__________________
Andrew Villasenor
805-720-5057
1984 300D turbo 5-speed manual(daily driver)
ALL MY DIESELS RUNNING WVO
Everything is for sale for the right amount
Ebay Store