2008 ML320 CDI - Oil Cooler Seals Replacement
Oofff. Coolant can leak from many areas after oil cooler seals replacement.
In my case, I did the repair a little while ago and I still have an oil leak.
The oil drips at the bottom of the bell housingdrainignfrom the left side .
The little drain hole on left is dry. I took a seringe a poured some water in the V valley and to my surprise water came down the bell housing and not the drain hole on the left. I am suspecting the gasket under the turbo piedestal or ... main seal.
I am drained of ideas or energy to mess with this.
By the way, do you have the torque specs for the 4 bolts conencting the turbo piedestal to engine block? I used 20Nm but I don't think is right.
I hope that by now you found your problem and had it fixed, easily.
All the best.
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.
They are telling me they can't get the turbo alignment tool needed to reinstall the turbo...
Anyone?






They told me even more after I had a loose oil cap.
New oil cap, cleaned up engine and a few months for the last pit of oil to work through, and now no more need for an oil cooler seal.
HMmmmmm?????
Wonder how many unneeded oil cooler seal replacements have been done?
The Best of Mercedes & AMG




If the seal is just weeping slightly, the sealant might work, but also is hard on filters and small passages.
My question after reading all these helpful DIYs is could their tech, in replacing the swirl motor, have disturbed or otherwise caused hoses into/from oil cooler to start leaking?
The other hits in this visit to dealer: transfer case needs to be replaced ($6,600), front air suspension leaking, needs bags replaced ($3,200), right front wheel bearing ($990), and rear brakes (no sure of cost b/c I didn't ask — I can do rotors and pads in an easy afternoon.)
Hoping our aftermarket extended warranty will cover transfer case, wheel bearing, air springs and oil cooler, but not holding my breath. We've been left holding the bill on aforementioned swirl motor and before that, AdBlue tank replacement because they were not covered.

TIA





TIA
What warranty do you have?
The policy was $4,500 when we bought the GL in 2012. If it doesn't come through this time, it was a tough lesson learned.
Every morning under the car there was oil leak, with size of a coin, after months "two coins"... and last... looses 1liter oil per day.
Common issue with oil cooler leak on om642. Cheap parts, but hard work.
My advice is to use service/garage with "know-how" about Mercedes engines/issues. Better more money, than bad engine assembly! I attached photo of the engine, after removing all parts, clear V-shape. You know how it looks like without cover.. you can't see V-shape.
It's cost of me $300($100 parts, $200 work) and 3 days without car.
Now i'm on test period, i hope no more oil leaks i next few years.




Every morning under the car there was oil leak, with size of a coin, after months "two coins"... and last... looses 1liter oil per day.
Common issue with oil cooler leak on om642. Cheap parts, but hard work.
My advice is to use service/garage with "know-how" about Mercedes engines/issues. Better more money, than bad engine assembly! I attached photo of the engine, after removing all parts, clear V-shape. You know how it looks like without cover.. you can't see V-shape.
It's cost of me $300($100 parts, $200 work) and 3 days without car.
Now i'm on test period, i hope no more oil leaks i next few years.
You did it yourself? If not, where did you get it done for $300?
. For those trying to diagnose, look for the weep hole just above the transmission lines at the rear left side of the block. Oil from this comes from the "V" and likely puts you into this club as well. Here's a picture of the weep hole. I ordered an OM642 oil cooler seal kit from IDparts that claims to have all the parts needed for the task, including the improved purple viton seals.
I'm currently starting to button up my '08 320 after replacing the seals, and the whole job is going to cost me about $C200.00 INCLUDING the service manual I found on eBay, a set of star drive sockets, a pair of click-lock pliers, and a #45 Torx socket (to remove turbo pedestal). I bought a seal kit from IDparts, and spent another few bucks at my local MB dealer for EGR and Y-tube gaskets, a new intake seal, and a replacement clip to attach the servo to the RH bank of mixer valves (it WILL break when you try to remove it).
Sadly, I found the new purple Viton seals were already installed, but the monkey who did the job (B4 I bought the car) didn't torque the thing down properly, allowing it to leak. He also crushed and tore the intake seal when putting the intake plenum back on, and broke the rear RH tab on the air box.
Bottom line, unless the job is outside my skill set or comfort zone, I never let "technicians" touch my stuff. This latest example just confirms that feeling. Do it yourself, and then you'll know it's been done properly.
The whole job takes a few days, and a lot of paper towels and vinyl gloves, but it is doable. I read these outlandish quotes and stories about how you need "special" tools etc to install the turbo (unless they're referring to $2.99 #45 torx socket needed to R&R the turbo pedestal) and I just shake my head. Get a service manual, set aside some screen time, and take lots of pictures. OTOH, if MB welches on the extended warranty, bring your car over to me on the Island and I'll do it for half that!

If there's interest, I'll post pics when done but they're already easy to find on some excellent earlier posts.
The culprit, deep in the belly of the beast.
Last edited by Harbro; Sep 8, 2016 at 01:24 AM.
Can anyone help with this??
looks like I might be joining the engine cooler repair club soon. Wife notice oil in garage, so I took a look. I cleaned all oil from underside of tranny/motor and checked after a short trip. Bottom oily again but no oil by the famous drain hole. Had MB dealer look at it as well. They say oil cooler and want 2500 + tax for it.
Is the drain hole the only place for the oil to escape the belly of the beast or can it run overtop and down on each side of bellhousing?
Greetings from Kelowna in Canada
looks like I might be joining the engine cooler repair club soon. Wife notice oil in garage, so I took a look. I cleaned all oil from underside of tranny/motor and checked after a short trip. Bottom oily again but no oil by the famous drain hole. Had MB dealer look at it as well. They say oil cooler and want 2500 + tax for it.
Is the drain hole the only place for the oil to escape the belly of the beast or can it run overtop and down on each side of bellhousing?
Greetings from Kelowna in Canada
No way oil can leak from cooler without exiting here (unless plugged)
Last edited by Harbro; Mar 9, 2017 at 11:02 PM.
No way oil can leak from cooler without exiting here (unless plugged)
I'll try to find out if hole is plugged up once I get back home in 13 days. Doing construction on a 14/7 rotation.



