So I love these 90s Benz’s. recently picked one up. this is the m119 engine.

Im trying to figure out what needs to be done as preventative maintenance, and timing chain issues seem to be one of the main things discussed. I will list what I know along with some questions. it seems terribly difficult to find info on these.

I opened the oil cap when i purchased it, and there seemed to be a bit of plastic under it, doing more research, i figured out this was the timing chain top guide. I dug further in, and found a good post on how to pin a m119 cam and check timing chain stretch. As it sits, the timing chain pinned at just over 6 degrees at the passenger side cam. All the guides seem good from what i can tell, except the passenger side top guide, which i replaced. the passenger side valve cover had some scoring like the chain was hitting it a bit.

Could this scoring be caused by the tensioner not working? the tensioner is on that side too, it seems like the slack is just on that side, as its the only part where it ate through a guide. Im wondering how much slack a failing tensioner would create. or could it be that top failed guide? it seems weird that that is the only side where the chain has signs of slack, the other guides seem to be in good shape.

the car is a 140,000 miles. I plan on doing a timing chain/ guide replacement a bit later down the line, but there seems to be no guides online for this, and the only info I have found is, its real hard. Some people online seem to think the chain should be replaced with over 4 degrees of stretch, some think just the guide replacement or tensioner will pick up some of the slack.

-Would changing the tensioner help/ any notes on what to be careful about doing one?

-anyone have experience doing a chain on one? I feel like I might be able to do it, if i had any sort of guide, or heard that anyone could pull it off. or maybe i should bring it to someone trusted.

-can i drive it the way it is for a few months until i can get to someone who knows these cars and can do the chain? I’m in north dakota and can’t find anyone who will touch the chain, and the dealer quoted me $4000 and i don’t think they know what they are doing. I also just got the car, and want to drive it some before dumping a bunch of money into a timing chain, only to figure out it has other major issues.

I keep looking on these forums for answers without actually asking questions, so figured I would interact for a change instead of just observing.

6 degrees is the limit for the chain spec, from what i've seen. the rh valve cover damage is because of that and/or a weak tensioner along with worn guides. i would not start it until it's fixed.

read this thread-

http://www.peachparts.com/shopforum/tech-help/398672-99-s500-m119-timing-chain-job.html

good luck, chuck.