Hello,

Yesterday I measured the valve timing in my 190D (OM601.911). I followed the 2mm valve lift procedure described in the FSM. Specifications indicate that the crankshaft angle with 2mm valve lift should be 11 degrees with a new chain and 12 degrees after 20.000km. I got 15.5 degrees. I repeated the whole procedure 3 times to make sure the gauge was perpendicular to the tappet surface.
This means that I am 4.5 degrees out of nominal. I guess I would need a 2 degree offset woodruff key to compensate for the stretch. Do you agree with this? Also, while these offset keys are available for OM617 engines, are they also suitable for OM60X engines?
I realise I would be better off replacing the chain, but I donīt feel comfortable with the riveting process. It got my attention that both the chain and the camshaft sprocket looked in very good condition, this is , the chain had very little play and the sprocket teeth were not hooked at all.

Thanks for reading
gonzalo

AFAIK, there are no Woodruff keys for the 601 engine. The chain must be replaced if the timing is not to spec.

You ought to confirm that IP timing is also late before you spend the money.............just to be sure that your procedure is good.

Thanks for your quick reply, Brian.

I measured the IP timing some time ago with the locking bolt and it was spot on, 15 degrees. I guess somebody adjusted the IP at some point before I got the car.

The procedure I followed to measure the valve timing is just as described in the FSM. By repeting the procedure 3 times I tried to minimise the risk of doing it wrong (i.e. gauge bad positon).

The marks on the camshaft and the head were slightly misaligned at crankshaft OT, reinforcing the idea that the chain is streched.

I will now consider replacing the chain.

Regards
gonzalo