Opinion on Timing chain replacement
 

I just purchased a 90 560SEL with 361000 miles. I have records for the last 160000 miles or so. It had the timing chain and guides replaced at 190000 which means it is well overdue. Would it be OK to replace the upper guides and the chain and not do the 2 lower guides? I really don't want to pull the timing chain cover as that requires removing the heads to do it right. If I have to do that, I will just pull the engine. I can't find any record of the water pump being replaced. Do they last that long? Any other recommendations other than timing chain, guides, w/p, and all fluids and filters. Car runs great. Has been serviced every 3000 miles like clock work.
Thanks
Paul

I always remove the valve covers & inspect the camshaft timing to be sure,
More than 3 degrees of stretch on the drivers side is a good case for replacement.

i know of 1 car and saw a 2nd that got just the upper rails, etc. replaced at that mileage. they both came back with jumped chains and bent valves. at 300k, the lower guides are just too far gone. good luck, chuck.

Sorry but all of this is greek to me.

I have 197K & no records
The engine sounds fine
Enrique MB motors says there is not need to do chain & to wait for a rattle.

anyway I am scared as I know w these engines if the TC breaks it destroys the engine.

I also have been told that the tensioner plays a bigpart in this as if it doesn't hold well, then the chain gets loose & the plastic parts get hit & break which is not good either.

I have heard that there is a way to tell how off the chain is by doing a measurement at the distributor or rotor or something to est chain stretch.

I took a practice & took off a drivers side valve cover
4 bolts & I was in there.

This was a engine in a junkyard
the plastic was med brown but the chain seemed to be tight
just a little play if you moved it.

Now if I got brave enough what can I do to try to check the play in the chain & it would be nice to do without opening the valve cover.

Is there something a novice like me can do?

Thanks:confused:

Just an update.
I checked chain timing and it was about 2 deg on the passenger side, which is fine. However I found the right head was leaking oil so I pulled the engine, will remove heads, replace guides and seals, check and/or replace valves, replace oil pump and chain and anything else I find needing attention. Problem now is the heat. Over 100 Deg in the shop the last couple of weeks and looks like it will continue for a while. Trans is going to the shop for a reseal/clutch replacement. Interior work will begin when it cools off also. This car will require a lot of work before it is put on the road but that is the fun part. Any other suggestions?
Paul