OM617 oil pump chain replacement? - PeachParts Mercedes-Benz Forum

83w126 · #1 10-04-2013, 12:20 AM

My car has over 400k miles on it, and I doubt the oil pump chain has ever been replaced. I need to replace the lower oil pan anyway (the drain plug threads have been damaged since I got it, and it leaks a bit both from there and the gasket), so I was wondering how much more it would take to change the oil pump chain at the same time. I haven't been able to find much information about how to do it, just a few posts mentioning that its a good idea to do on high mileage engines, and showing the parts you need to do it.

t walgamuth · #2 10-04-2013, 05:53 AM

I agree its a good idea and also wonder how hard it is.

1960mog · #3 10-04-2013, 10:33 AM

To replace the oil pump chain you have to remove the upper oil pan and all the pulleys and dampers on the front of the crank shaft.
Also remove the aluminum flange that holds the front crank seal from the engine block.
Remove the 8mm bolt from the oil pump sprocket and remove the sprocket together with the chain.
The oil pump sprocket is mounted on a taper, it can be hard to remove.
New oil pump chains are usually delivered endless, they have no master link.

charmalu · #4 10-04-2013, 10:54 AM

Don`t forget this little goodie, the chain tensioner. I had one cracked on two sides, if it had gone another 1/4" on either crack, it would have fallen off.

1984 Mercedes-Benz 300D Sedan - Oil Circulation - Page 2

Charlie

t walgamuth · #5 10-04-2013, 02:11 PM

So there is no way to roll one in? Is the tensioiner rail changible from the small pan opening?

whunter · #6 10-04-2013, 04:05 PM

Quote:

Originally Posted by t walgamuth

So there is no way to roll one in? Is the tensioiner rail changible from the small pan opening?

NO.

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83w126 · #7 10-04-2013, 04:56 PM

Does the engine need to come out to do this in a way that makes sense? I know there are a lot of jobs that are technically possible to with the engine in the car, but taking it out would decrease the time enough to be well worth it.

Or is it even worth doing a job like this on an engine with mileage that high? It does still run fine, but it seems like most of them dont last this long. The other choice is to just drive it until either the oil pump chain or timing chain break, and swap in another junkyard engine (if I found one while this engine still runs I could replace the oil pump chain and timing chain before putting it in the car too).

Diesel911 · #8 10-04-2013, 08:08 PM

All of the Oil Pump Chain Failures I have read of on the various Mercedes Forums had a no-chain parts failure that caused the failure.

Wear wise I think the Gear Teeth on the drive gear are more likely to get chewed up than the Chain Break.

engatwork · #9 10-04-2013, 09:25 PM

I've seen some oil pump chain tensioners pretty used up after about 300k miles.

whunter · #10 10-05-2013, 02:36 AM

Quote:

Originally Posted by 83w126

Does the engine need to come out to do this in a way that makes sense? I know there are a lot of jobs that are technically possible to with the engine in the car, but taking it out would decrease the time enough to be well worth it.

Or is it even worth doing a job like this on an engine with mileage that high? It does still run fine, but it seems like most of them dont last this long. The other choice is to just drive it until either the oil pump chain or timing chain break, and swap in another junkyard engine (if I found one while this engine still runs I could replace the oil pump chain and timing chain before putting it in the car too).

You have an e-mail waiting..

.

83w126 · #11 10-06-2013, 04:46 AM

Thanks for the information, it makes more sense now that I see what the parts look like. Is there room to remove the upper oil pan with the engine still in the car? It looks like there might be, but its hard to tell. If I replace the oil pump chain and timing chain, are there any other likely mechanical failures that would cause major damage but can be prevented somewhat easily?

The oil cooler lines and vacuum pump on my car both appear to be fine, it still has good oil pressure and the blowby doesn't seem excessive compared to others I have seen, and I am almost done swapping the turbo that didn't turn anymore with another used one in reasonably good condition. I'm just wondering if there is anything else that I should worry about, I know that theres no way of knowing what might break on a car with 400k miles on it, but I would like to try to at least fix anything that is an obvious problem.

whunter · #12 10-07-2013, 01:47 PM

Quote:

Originally Posted by 83w126

Thanks for the information, it makes more sense now that I see what the parts look like. Is there room to remove the upper oil pan with the engine still in the car? It looks like there might be, but its hard to tell. If I replace the oil pump chain and timing chain, are there any other likely mechanical failures that would cause major damage but can be prevented somewhat easily?

The oil cooler lines and vacuum pump on my car both appear to be fine, it still has good oil pressure and the blowby doesn't seem excessive compared to others I have seen, and I am almost done swapping the turbo that didn't turn anymore with another used one in reasonably good condition. I'm just wondering if there is anything else that I should worry about, I know that theres no way of knowing what might break on a car with 400k miles on it, but I would like to try to at least fix anything that is an obvious problem.

It is theoretically possible with the engine in the car....
But it is difficult, IMO dangerous, and takes considerably longer.

.

pawoSD · #13 10-07-2013, 02:58 PM

I think if the engine has 400k+ its coming up on full rebuild time soon anyways. I'd either plan for that, or leave the pump chain alone....

83w126 · #14 10-08-2013, 02:09 AM

Quote:

Originally Posted by pawoSD

I think if the engine has 400k+ its coming up on full rebuild time soon anyways. I'd either plan for that, or leave the pump chain alone....

It seems to still run fine otherwise, so I was hoping it might last a bit longer than that. It seems to be leaking quite a bit from the upper oil pan gasket anyway (not really enough to cause a noticeable drop in oil level, but enough to make a mess wherever I park it), so changing the pan gasket wouldn't be so bad anyway.

t walgamuth · #15 10-08-2013, 06:42 AM

Quote:

Originally Posted by 83w126

It seems to still run fine otherwise, so I was hoping it might last a bit longer than that. It seems to be leaking quite a bit from the upper oil pan gasket anyway (not really enough to cause a noticeable drop in oil level, but enough to make a mess wherever I park it), so changing the pan gasket wouldn't be so bad anyway.

I'd try to isolate the leak. The upper pan gasket is not known for leaking.