Anyone ever had a problem with W124 oil pump chain? - PeachParts Mercedes-Benz Forum

jbach36 · #1 07-10-2016, 01:31 PM

Since my car is now over 200k, I eventually need to get the timing chain replaced, even though the car sounds fine to me at this point.

I called one shop and they said they also pull the engine out of the car to replace the oil pump chain. He said "if we do the timing chain and 3 months later your oil pump chain breaks, you're going to be really mad at us".

So I'm just wondering if that should be done too. Has anyone ever had a problem with their oil pump chain? I called another shop and he said they never change that.

jeff 1991 300d, 205k

bsmuwk · #2 07-10-2016, 05:57 PM

Let's be honest here, if he went so far as to tell you they're that thorough with chain replacements, then I'd consider that a decent shop. The fact they even knew the motor has a chain for the oil pump is good news lol

With that out of the way, I've only ever had to replace one oil pump chain - that was because the pump grenaded and took the pump drive gear with it. There's also a little spring loaded tensioner for the OP chain to replace as well. I've replaced multiple chains/guides with the oil pump set up never being touched and they've been fine. Though, it's not much more expensive to just do the OP chain and be done with it. Just ask for the old parts when they remove them is all.

Let's put it this way - that oil pan will be getting resealed and the whole front half of the motor will be resealed as well. You won't have to worry about any of that for quite a bit of the cars life.

engatwork · #3 07-10-2016, 08:35 PM

You should easily be able to run past 250k miles. Everytime I have ever torn into one with 250k + miles the oil pump chain tensioner is the one showing the most wear.

Jeremy5848 · #4 07-11-2016, 12:01 AM

Rolling in a new timing chain is relatively easy and not expensive even if a shop does it. Pulling the engine is another matter—many more hours of work. Although the shop's point is well made, you are the one paying for it. They can be as conservative as they want so long as it isn't their money being spent.

At 200K your engine is not excessively worn so long as it hasn't been abused and the oil has been kept clean. The first thing you should do is to check the timing chain stretch. If it is minimal, it doesn't need to be changed and the oil pump chain is likely also OK. At 275,000 miles the timing chain of the OM606 engine in my '96 E300D (similar engine, different chassis) had a stretch of only 1 degree. The car is now at 305,000 miles and running well (knock on wood).

Jeremy

ah-kay · #5 07-11-2016, 12:35 AM

Oil pump chain does snap. It happened on my 300SDL, OM603 engine and engine seized. Yours is a OM602 which is similar but not the same. Engine does NOT need to come out to replace the oil pump chain. If the shop thinks it needs to come out then find a different shop.

jbach36 · #6 07-12-2016, 01:49 AM

Quote:

Originally Posted by ah-kay

Oil pump chain does snap. It happened on my 300SDL, OM603 engine and engine seized. Yours is a OM602 which is similar but not the same. Engine does NOT need to come out to replace the oil pump chain. If the shop thinks it needs to come out then find a different shop.

I called a few other shops, they too said the engine would have to come out to get to the oil pump chain. Maybe there's a way to get around that, but not a great way to get around that. I don't know, just what I'm hearing.

And maybe I'm even giving the wrong part, maybe it's a different chain but I think he said oil pump chain.

ah-kay · #7 07-12-2016, 01:57 AM

Quote:

Originally Posted by jbach36

I called a few other shops, they too said the engine would have to come out to get to the oil pump chain. Maybe there's a way to get around that, but not a great way to get around that. I don't know, just what I'm hearing.

And maybe I'm even giving the wrong part, maybe it's a different chain but I think he said oil pump chain.

They are wrong. Drop the oil pan, a pain as you have to lift the engine about 4" to clear the cross member. Cut the chain and put in the new one. The new one comes with a master link and crimp it in place, it is not a continuous loop.

Clemson88 · #8 07-12-2016, 09:50 PM

I've never heard of an oil pump chain causing trouble on one of these engines until this thread. The timing chain is a piece of cake to change. You just have to remove the accelerator linkage, breather assembly, chain tensioner and valve cover. It takes a crimper to get the new chain linked but the old one is removed by grinding the crimped buttons off one of the links. Two, three hours start to finish maybe less if one has done it a few times and has competent help.

Mxfrank · #9 07-12-2016, 10:01 PM

You do hear about problems with 60x oil pump chains, just not often. Mine has 390K miles, I probably should change it.

I can only speak to my 602...as mentioned, everything can be accessed by dropping the pan. Not that dropping the pan is without complications, but it's a lot easier than pulling the motor. On the 602, Mercedes recommends installing a new pump gear when you change the chain, don't know why.

Clemson88 · #10 07-12-2016, 10:05 PM

Quote:

Originally Posted by Mxfrank

You do hear about problems with 60x oil pump chains, just not often. Mine has 390K miles, I probably should change it.

I can only speak to my 602...as mentioned, everything can be accessed by dropping the pan. Not that dropping the pan is without complications, but it's a lot easier than pulling the motor. On the 602, Mercedes recommends installing a new pump gear when you change the chain, don't know why.

I guess the engines changed more than I knew. Either that or everbody replace their oil chains without check with me.