Originally Posted by Maj. Dundee

Feri, you must open your own separate thread by explaining your friend's problem and tell us the year and model and whether it is gas or diesel.

Originally Posted by CourtneyW

Yes, those are necessary. I probably purchased more than I should but I'm also replacing the oil filter, fuel filter, air filters. I purchased some different seals, gaskets, bolts and other items that people recommend on posts that I came across. So far my husband and I have removed the turbo, or should I say he removed the turbo! And it was a pain! Next is the intake manifold. Once we get that out I can post a list of items that we replaced.

I also saved instructions from WIS (PDF's), $160 for a one week subscription was the best money I ever spent! If anyone would like a copy I would be more than happy to email them to you, just PM me.

Any advice on removing the carbon build up? EGR valve, intake nanifold.... what else will have carbon build up that you can remove yourself? And I apologize, this is the first time I have ever worked on any vehicle besides an oil change and replacing break pads. When the dealer quoted me $3,100 to replace the oil cooler, oil cooler seals and turbo inlet seal I laughed after I found out how much parts were. Honestly, the dealer will never touch my vehicle again. If I can understand directions from WIS, anyone can! This job is extremely time consuming and meticulous, but it's totally do-able.

Originally Posted by LoxSmith

Catalind - You guessed it right. I just finished this evening. I don't know how I did it but one of the o-rings was pinched out of the groove on that little crossover piece. I must have jostled it when I put it in the first time. After replacing the oil cooler seals, I had to take the whole thing apart again to replace that o-ring. I searched for the source of the leak for hours. It was on the bottom fuel filter side of the crossover and dripped on the floor the same place as the oil cooler leak.


Shame on me - I didn't have the torque specs so I used my little 6" rachet and popeye forearms. Spot torque is what we called it in the Navy. I saw spots after tightening each of them.


I have 160k on this 2008 ML 320 CDI. I'm just hoping to get another 40k out of it.


Thank you for the reply. I was really stumped.

Originally Posted by Brandon314159

Hey all,

Decided to replace my oil cooler seals on the OM642. I had a 'mystery leak' that was appearing on the driveway from the drivers side rear of the engine block. Eventually traced to the center of the valley of the V6 and the obvious culprit (after much probing with the boroscope) was that the oil cooler seals were failing.

Car has about 175K on the clock.

I also cleaned the intake manifolds, EGR plumbing, swirl motor flaps, and intake ports of the heads of the EGR+oil goo that was coating everything.

I took some photos and even have a time lapse video that I'm working on. The photos are already up so here's a link:

https://plus.google.com/photos/11000...23881113808401

If linking to third-party photo sites are not allowed, I can put a few up here if needed.

Hope these help someone and I'm happy to answer any questions if anyone is thinking of doing this job themselves. It took me about 9-10hrs with some help with the cleaning process. I also tore down the turbine housing to inspect the VNT/turbine (which took extra time) because I suspected some damage (which there was).

The swirl motor linkage was by far the most fragile part of the experience. I heard the horror stories so I was ultra careful disconnecting things. Spent about $50 in parts from Mercedes (gaskets) to the job.

Take care,