R107 M116 cam timing mark way off

[panzerloren]

Hi all,

Innocently enough, I wanted to check the "stretch" on the timing chain in our'85 380SL. However, the camshaft and crankshaft timing marks aren't even in the same ballpark. The picture included here is where the camshaft timing mark is when the crankshaft is at TDC. This is the passenger's side cylinder bank (USA).

I thought maybe the harmonic balancer slipped, so to check that, I pulled the spark plug from cylinder 1, stuck a chop stick in, and watched its travel as I rotated the engine--its travel matches the markings, so no dice there.

The weird thing is the car is running fine. So I'm wondering if the marker on the camshaft is wrong? The mark is on the compensating washer--is it possible for that to get out of alignment?

According to the service manual (https://www.startekinfo.com/StarTek/outside/11883/PROGRAM/Engine/107/M116_38/05-220.pdf) the intake valve is supposed to open 22 degrees ATDC, so I could verify the camshaft position that way.

Any idea what could have happened or what I can do? Thanks!