OM603 Timing Chain Tensioner Screw Up - PeachParts Mercedes-Benz Forum

JHZR2 · #1 04-29-2023, 01:59 PM

I’m trying to pull my injection pump. I need to remove the timing chain tensioner. I think I screwed up.

Issue 1: I removed the cap not the big hex. I thought the big hex was intended to keep the body of the tensioner in the engine. I think I screwed that up. It came out in parts. I don’t think I lost any.

But I did mix up which end of the big spring is what. There are two different ends, one with a black top and four small holes, the other with one hole and an o-ring. The o-ring looks squashed so this may be a blessing in disguise. Dare I pick it out and try to replace?

Doesn’t it seem like the one I just showed above would be part number 232????

Issue #2: should I remove the larger hex from the engine? Hindsight yes, but if I’m going to get it all back together (and filled with oil) then maybe I don’t need to?

Issue #3: I’m working from the FSM. The chain tensioner section indicates that it needs to be removed with the engine at 0. The IP removal section implies that you set the engine at 14deg then pull the tensioner. Which is right or does it matter?

Issue #4: I didn’t look if the first cylinder was in the intake or combustion stroke. I know the timing pin shows through the window. FSM doesn’t seem to indicate that it matters, but I’ve read that elsewhere. Do I need to turn the engine if the wrong lobe on the cam is up? If so, I assume I need to get the tensioner back in. So then I’m stuck/screwed for a while. Thoughts?

Thanks for any guidance you can give!

JHZR2 · #2 04-30-2023, 12:04 AM

Well I was able to press the tensioner back together and screw the small cap into the bigger body. Was a “barely feasible” thing.

I didn’t prime it with oil. Hopefully turning the engine some number of times will suffice.

I put it all back so I could feel safe turning the engine by hand to find the locking pin for the IP. I think since I have the timing basket I’ll not remove it again, even with the bigger housing with a larger socket.