What priority is 60x Timing chain maintenance - PeachParts Mercedes-Benz Forum

DieselJim · #1 03-06-2012, 04:15 PM

My '92 300D 2.5 Turbo has almost 304K miles almost certainly all on the original timing chain. Mobil 1 TDT has been its exclusive oil for almost 130K of these miles. Am I living on borrowed time? If I want to drive the car until the rest of the engine is worn out should I change the chain? I've read threads where it seems to suggest that the timing chain is low risk even at high miles for the 60x series. I have read threads that suggest I am on borrow time. Obviously it could break on my way home from work today or it could last another 300K miles.

engatwork · #2 03-06-2012, 04:36 PM

I assume you have never had to replace the head gasket?

Replacing the guides, chains and tensioner slides is easy with the head off. It is doable with the head on but a little more cumbersome. I'd be more concerned with the plastic bits under the timing cover than the chain if I were you. Based on what I have seen the timing chain tensioner slide will be the one showing the most wear on your application.

DieselJim · #3 03-06-2012, 04:44 PM

With the plastic bits coming from the deterioration of the tensioner slide?

Brian Carlton · #4 03-06-2012, 04:46 PM

Quote:

Originally Posted by DieselJim

Obviously it could break on my way home from work today or it could last another 300K miles.

The chain doesn't break without a precipitating event.

One of the guides comes apart and jams the chain and then it fails. Changing the chain, exclusively, provides a false sense of security to those who listen to the "change it" crowd.

Only if the chain has elongated beyond limits and the IP timing is off specification should it be changed without addressing any of the guides or tensioning rail.

If you aren't going to do the entire job, including reconditioning the head, I would leave it alone.

DieselJim · #5 03-06-2012, 04:50 PM

Good advice. I think my answer then is drive it until it dies or I don't want to any more. The head job is a good idea but I really don't see putting that kind of money into this car. Especially with what the market is for its peers. If I want to drive a 124 for a long time I'll look at a 95 with a 606!

Brian Carlton · #6 03-06-2012, 04:53 PM

Quote:

Originally Posted by DieselJim

Good advice. I think my answer then is drive it until it dies or I don't want to any more. The head job is a good idea but I really don't see putting that kind of money into this car. Especially with what the market is for its peers. If I want to drive a 124 for a long time I'll look at a 95 with a 606!

Exactly.

You open it up and will dump $2K in parts and labor (machine shop) by the time you're done. The remainder of the vehicle would need to be pristine to justify it.

And, it will be out of service for a couple of months.

engatwork · #7 03-06-2012, 04:55 PM

If the a/c works then you have a car that is probably worth keeping going. With that said if you ever want to get rid of it let me know.

DieselJim · #8 03-06-2012, 07:24 PM

Well the previous owner did do the evaporator job and the A/C is cold and I did the transmission a little over two years ago. I definitely hope to get close to 400K from it.

My 95 e320 that has a blown cylinder is for sale though. I have to move it. Or I'm going to take the wheels and a couple of other things and send it to salvage.

shertex · #9 03-06-2012, 10:05 PM

I've got exact car with 233,000 miles on it (and another with 101,000 miles). Recently I thought about getting the chain stretch measured....my indie would charge about an hour's labor to remove the valve cover, etc... But I'm probably just going to let it ride. Your 304,000 miles emboldens me!