Timing chain tensioner 1976 230/4 123 series

[cumined]

Dear Friends

I recently replaced the head gasket on this car. It runs perfectly but I now have a metallic clanking from the front general vicinity where the timing chain is located.

Could a non or mal-functioning chain tensioner give this kind of symptom? My tensioner has a hex cap that seems to give access --but once removed all that one sees is a small round hole and no sign of anything that can be adjusted . Tomorrow I am planning to remove the whole device, hoping that if it's replaced or (adjusted??) this clanking noise will go.

Any views , tips or diagnostic suggestions will be very much appreciated.

Thankyou

Ed