560 sel

My mechanic says the timing chain last 150k to 200k miles, what have been your experiences? Thanks in advance.

There are offset woodruf keys to adjust timing. I think they go to 10 degrees. After that, replace the chain.

THere is no official life of a timing chain but the guides are plastic and, especially if overheated, can break and jam between the chain and sprocket. This will cause the chain to jump and when the motor is out of time, pistons and valves will try to share the same space. The motor will then need a complete rebuild that will run in the $6000 range.

Some mechanics on this site recommend 120,000 intervals for the chain, rails and tensioner. I did mine at 100,000 because I fear that the old owner didn't maintain it. It was a precaution.

My $0.02

Steve

If you have proper maintenance records and know for sure that oil was changed frequently (and hot!), I wouldn't worry too much.

A particular MB mechanic comes to mind when he told me that he never ran across a late model (1990-91) 560SEL that had a broken chain.

I'd do it for peace of mind before 200K miles... Mine has 103K and will see this work done sometime in the next year. Again, peace of mind, so I'm good for another 100K!

Please note that the chain usually doesn't break. It can stretch so much that the motor cannot be set for proper timing but the catastrophic result is usually from a broken guide, not the chain itself. I understand that if the motor overheats, this is more likely.

Steve