The oilcooler seals are among the least expensive parts you have to buy if you have ever need to replace them.
You need two of them A 642 188 04 80 is the part number and these are made with the new Viton material. They are sold for $ 3.60/ piece by Mercedes Genuine parts.
However, if you need to replace these, in order to get there, there is a multitude of other seals and gaskets that need to be replaced. ( for me it was $ 154 total).
Wish you best of luck if you ever have to do this by yourself. It's doable and probably nobody will do it better than you. A lot of cleaning involved if you want to do it right.

 

hi catalind, thanks for the info. ,ay i know the other gaskets that i would be needing for the replacement? and if you have the part number so i can place an order. Yes im planning to do this myself. right now my ML is just at 36k miles, no signs of leak yet. Im planning to do this when i see signs of oil leak. thanks for your reply. :smile

 

Well i have 135,000 miles on my 2008 and no leaks/ no oil cooler seals replaced, so maybe hold off and it wont happen at all or not for a long time....

 

ML320 CDI - Replaced the oil cooler seals at about 125,000. There was no dripping on the floor but there was visible leaking. Apparently there was not a fast enough leak that was not evaporated or blown off but there was evidence of leaking in the under-engine shroud. I was using at least a quart of oil between changes. Since the seal replacements there has been no decline of oil.

 

Hi catalind, i already shipped the ml to the Philippines. And the weather there is about 37 to 40 right now so its really boiling hot. Saw the list of the gasket and seals. Just one question? Is your engine a bluetec? Saw some parts that has bluetec. Mine is an 08.cdi non bluetec. Would it be the same if it was on mine? Thanks

 

its prob not your rear main. I have never seen a rear main leak on a diesel. the issue you have is oil has gotten b/t eng and trans and is still dripping down. I have had to pull trans to clean b/t eng and trans. Good luck.

There is some differences in some gaskets b/t bluetec and non bluetec if not mistaken. the parts to do the job from my dealer is around $200 plus fluids. you will need coolant and an oil and filter.

 

Thanks vortecpwr. Ill check on epc.

 

Catalind, is there a DIY link to replacing the oil cooler seals? Local dealer wants thousands to replace seals supposedly leaking into the valley of the wife's 2011 ML350 bluetec. From the one partial video I have seen, it looks like a lot of disconnecting/reconnecting to get to the oil cooler, otherwise not too complicated.

 

Just a question not meant to offend any member.

Is it time that we make a sticky for oil cooler seal failures on all diesel W164 MLs?
It appears that all of them have had this problem or will have this problem.

 

+1 hoping someone can give time for this. :smile

 

Good idea Noodles.

 

they will all have this issue at some point in time in their life. they may even have it 2 or 3 times.


I have seen new diesel vehicle with 5k miles have oil "seepage" between the eng and trans. I say its a diesel. they leak/seep oil.

 

Are you talking about the oil cooler seal failure occurring 2-3 times??

 

I think it is already done.
Please Google ¨A journey to the infamous OM 642 oil cooler leak ¨
I am planing to do it in short.
All the best
Argenjagd.Argentinien
Ml 320DCI 2007, 122.000Km
MB 190 2,2D 1984, 350.000 Km
MB 300 TD, 1980, 450.000Km
All running beatifull

 

A journey to the infamous OM 642 oil cooler leak

That is a very nice description of the job. However, please be aware that some torque values specified in that thread are not right. Turbo pedesthal bolts torques are one of them that I can remember now. Anyway, double check torques. I ended up taking the turbo off a second time thinking that I may have turbo leaking. Unfortunately it was not ....

Little leak still exists and I know is not the cooler. I suspect rear main seals but I 've seen few responses ( thank you ) where people are thinking that it may be some oil trapped left from the " big leak" . I wish and I hope they are right but I doubt it.
After replacing oil cooler seals and still have leak, I tried desperately to identify the source. I think that I poured a bucket of water in the engine valley ( little by little :eek) to see where the leak may come from.
If oil was trapped between engine and tranny, the trend of what I am suspected to be a rear seal will be decreasing and eventually will stop when the oil trapped oil will be gone, but is not.
My explanation of the rear seal mess up is: The previous owner noticed the leak ( oil cooler leak) and afraid that he lost oil, he replenished with too much.

ADVISE: After you change seals, and most likely you will clean your intakes very well, including the intake holes in the heads, some of the crud may get into the engine. If you have BLUETEC, that resulted soot will clog your DPF filter. If I knew what I know now, I would have start the engine (after seals replacement) without connecting the turbo to exhaust and let the car idle like that for few minutes to get all that stuff out and not in the DPF. ( probably it will be loud).
I think that I have to take my DPF out to have it cleaned. Even though it went thru few regeneration cycles I still get error codes related and check engine light on.

 

yes. IMO they are not fixing the issue. they have just changed the seals. If you ever see how it is mounted in the valley you will see how/why it leaks. the bolts only hold the perimeter down. hot/cold 1000x will cause the cooler to warp and cause a leak. if they had put 1 or 2 bolts in the middle of the cooler to help hold it down the cust would not have this issue and I would not get to charge customers 13-15 hours to repair their oil leak.

now this is just my opinion. its in a horrible place. lets put a cooler in the hottest part of the eng. what the heck were they thinking. oh that's right, they weren't. Why not install a cooler form the oil filter housing to the radiator or to a small cooler in the bumper? I understand this would make the power plant "bigger" (due to more hoses) and cost maybe an extra $32 per eng, but it makes better since.

 

Well I had not heard that the coolers were warping. I just thought it was the seal material failing. My local indy told me they never replace the coolers themselves. I agree with you about the insanity of the location of the cooler. Why not place it on the oil filter housing like on the 3.5 engine???

 

I haven't seen one warp either. its just my theory that this cooler when it get hot/cold multiple time it will distort and cause the seals to eventually leak.

there really is no way to reroute/rework this to install and external cooler.

like I have stated on here I have done a 13 ML cooler and it had the newer seals. another tech has done a 13 as well and it had the newer seals. I believe MB has no idea how to solve this. I will say on the sprinters we see them last a lot longer before they leak. not sure reason why. maybe is due to the are running a lot longer between trips? who knows.

 

When I replaced the oil cooler seals besides changing the bolts I used spring washers. When I removed the cooler I found some of the bolts very lose. I think I could have broken them out by hand. My opinion is that the old sealing material ( I hope that the new VITON doesn't do that) squeezes under bolting load and due to repetitive thermal cycles loses its elasticity. I hope that my spring washers will keep some elastic "push" on cooler, then seals. No idea if it works because I just did this around 1200 miles ago.

 

havent crossed the path of replacing the seals. i seldom used my ml. now its at 37k miles, but im ready as soon as i see early signs.

 

2010 ML 350 Blutec with 140,000 miles in the shop for a third oil cooler leak. The first at 50k, the second at 90k and now the third at 140k. We purchased the extended warranty so the first two were on Mercedes. Incidentally this time they replaced the rear main first but that didn't fix the problem. I understand that Mercedes is aware of this problem with oil cooler leaks on this vehicle but are unwilling or able to find a permanent solution. I have heard talk of a class action.

 

Mercedes should address this problem once and for all.

 

i agree

even though my 2008 ml320 has not had the oil cooler seal leak yet, this has been a huge problem for these motors and seems like it should have had a recall

did a lot of research before i bought my truck and budgeted for this repair before i purchased one

 

Cost them at least one customer (me) I was really taken with the idea of getting a lightly used and very well taken care of 2010- 2011 ML350 BLUTECH ... but the 3 I found that met my specs (low mileage, mint condition) all had OIL COOLER leaks as discovered in Pre-purchase inspections.

I finally said screw it and bought an AUDI Q5 3.0 TT ... still under factory warranty, and the wife loves it. Kinda sad... this is the first non-Mercedes vehicle I have purchased in 12 years !

But hey - pretty clear to me that if these BLUTECH's aren't leaking, they will be, and $2800 local repair still does not guarantee against future failures... you are right, MBZ should have bellied-up from an engineering standpoint and come up with at least a better long term "fix" by now.

Can't be that hard ... it's a frickin oil cooler for Christ sake !

 

it should have an action like the balance shaft failures on the petrol. its really unfair and inconvenient for all 0m642 owners. class action suit should be the path for this.

 

I have heard that when Mercedes went from the straight 6 in the 05 and 06 CDI To the v configuration they had a major problem with oil leaks around the oil cooler. Anyone else know more?

 

yes, its a known problem

 

For those who have replaced their oil cooler seals,

About how many hours of actual work would you say it took to do the job?

Just trying to decide if I want to do it on my own.

Have heard various numbers, all the way from 5 hours (from someone who did it on a Sprinter and has done 8 of these, so he's an expert) all the way to 23 hours that an MB dealer quoted someone.

Most common seems to be about 10 hours. Does that sound right?

Truck is mostly highway driven, and not idled much at all. So I'm not planning to clean out manifolds of carbon or anything. Will just clean up (may pressure wash) the oily parts once they are off the truck before I reassemble. So don't include more than about 1/2 hour of cleaning time in your total estimate.

Would 10 hours of actual work be a good estimate or am I too high or too low?

As far as background, I do most of my work on the truck, have done similar jobs at this complexity level in the past, and have all of the necessary tools and parts already.

 

There's a video on youtube that shows 4 or so hours for an experienced person. I took one look at the high-speed video of the job and said to myself "I'm out!" and spent the $2k for the replacement. The parts are less than $50 so I told the guy to replace then entire oil cooler ($200) since I'm already spending this money on labor to get down there. Note if you're in the Mercedes club of America you can get 10% off.

 

first one took me about 10 hours, but I took way more off than was needed.

I have them down to about 5-6 now. have a co-worker can do them in about 4.5 hours.

we are both MB techs and have done several. We dont clean the intakes out, just the valley where the cooler is.