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Hi,
I own an ML320 CDI with over 200K miles on the clock (2008). VIN 164122A341045
I have a bad oil leak to the rear of the engine. I removed the under belly tray which was saturated in oil and cleaned down all the oil, most of it to the rear of the engine. I then took the vehicle for a short drive and literally what I had cleaned was covered in oil again with it dripping onto the ground. The leak appears to be up high at the back of the engine behind the turbo area and drips down on the passenger side of the bell housing (right hand drive vehicle). See photo (after 4 miles of driving). I have recently replaced the turbo seals at the inlets but hasn't made a difference. Any thoughts on source? If it was an oil cooler seal leaking would the oil be appearing so high up at the back of the engine?
Last edited by mercmatic; 12-29-2020 at 03:16 PM.
Reason: VIN inc.
Please post your VIN. Someone can look up the parts and procedures relative to what might be leaking on your vehicle.
You have the OM642 engine, correct? Could it be the oil cooler seals are leaking? This is a well known occurrence for the OM642. The search function on this site will bring up many discussions.
Item 39 in the diagram. It can be done DIY and is a challenging and time consuming repair. If this is your situation.
OK. Can you do more diagnosis to confirm the leak is from the oil cooler? This is extensively addressed on this site, try the search feature to help in diagnosis. There may be WIS instructions also attached to the posts.
OK. Can you do more diagnosis to confirm the leak is from the oil cooler? This is extensively addressed on this site, try the search feature to help in diagnosis. There may be WIS instructions also attached to the posts.
First i would wash the engine and take it for a short drive and then inspect where the leak is coming from. If it is the oil cooler which appears on the driver driver side(not refering to right hand driver vehicles) where the engine meets the transmission, then as per your photos this is the side where it is leaking. If after the engine wash and drive the leak is coming from the same spot as shown in the picture most probably you have an oil cooler seal leak.
To provide an update I cleaned down all the oil and took it for a short drive.
Firstly there is no oil coming through the weep hole, the oil is coming from higher up. It flows down the bell housing and appears to be coming from an area to the rear of the turbo. I must get a probe to see up at this level or else remove the turbo to see what is happening. It doesn't appear to be from the oil cooler seals.
To provide an update I cleaned down all the oil and took it for a short drive.
Firstly there is no oil coming through the weep hole, the oil is coming from higher up. It flows down the bell housing and appears to be coming from an area to the rear of the turbo. I must get a probe to see up at this level or else remove the turbo to see what is happening. It doesn't appear to be from the oil cooler seals.
To provide an update I cleaned down all the oil and took it for a short drive.
Firstly there is no oil coming through the weep hole, the oil is coming from higher up. It flows down the bell housing and appears to be coming from an area to the rear of the turbo. I must get a probe to see up at this level or else remove the turbo to see what is happening. It doesn't appear to be from the oil cooler seals.
If it is coming from up and the right cylinder bank then check the PCV valve and the cap under the pcv valve because oil can run down due to a bad o-ring.
I had the exact same symptoms, oil leak to rear adn front of engine . I also had Oil in coolant !!! . after major stripping found that the oil cooler was in terrible bad shape and clogged, Also cleaned out the exhaust manifold which was badly fouled up, Decided to bit th ebullet and replace the entire Oil cooler as this is a BIG job to access the oil cooler NB rememebr to order and replace gaskets for all parts stripped perished ...... Good Luck
Thanks to all for the help on this so far.
I have determined that the leak is most likely from the oil cooler as I now have oil coming through the lower weep hole, i have read all the relevant posts on this site which are excellent.
I am planning to strip it down in the coming weeks and have a few questions;
My turbo has done in excess of 200K miles should i get this reconditioned at this stage when it is out?
Should I replace the swirl flap linkages and is this a difficult task as these appear very delicate?
With over 200k miles, are you open to the idea of repairing the oil leak, then selling the vehicle? The OM642 is troublesome and will cost you lots more money as time goes on. Even the non-DEF/DPF/SCR engines as you have are troublesome at high milage, as you are experiencing.
Putting money into the turbos seems to me like an unattractive investment of time, energy and money. Buy a W166 gasoline V6 that meets your price range. Or a Toyota 4Runner. These will serve you better than an old OM642.
To provide an update on my leak. I bit the bullet and stripped down to the oil cooler. Yes the oil cooler seals were goosed. I had some doubts as to whether the oil cooler seals were the problem as most of the oil leak was leaking to the rear of the turbo and dripping down the bell housing as opposed to coming through the lower weep hole. It became apparent when I got cleaning around the oil cooler as the weep hole were nearly fully blocked with grit from the years of motoring. I cleaned all the intake manifolds. These had gunk built up on them and this cleaning is what took most of the time. The short EGR pipe at the front of the engine was the worst affected as it was practically fully clogged with carbon. Thanks to all the help and posts on this forum, without this I couldn't have completed the task.
So I have it all back together and it is dry. I have one fault code which I must resolve and looking for some guidance.
The code is 2513 "Check component M55 (Inlet Port Shutoff Motor) Positioner signals fault. This refers to the swirl flap motor which was replaced already a number of years ago. I am in limp mode. The check engine light is not on. I replaced the linkages with aluminium ones when doing the oil cooler seals as the old ones were worn and not working. The linkages are all moving freely and in unison. I checked fuses within the engine compartment and all are fine. What could this be aside from the swirl flap motor itself?
Things you could try:
Clear the code and see if it comes back. Not all scanners will be able to clear the code.
Or, resistor mod (4.7 mF) across the 2 center pins in the swirl port motor harness/plug - code should clear itself then.
If it doesn't itself clear after a few drive cycles there's a problem in the harness or ECU.
But it's not impossible that you have a 2nd cooked swirl port motor...
Things you could try:
Clear the code and see if it comes back. Not all scanners will be able to clear the code.
Or, resistor mod (4.7 mF) across the 2 center pins in the swirl port motor harness/plug - code should clear itself then.
If it doesn't itself clear after a few drive cycles there's a problem in the harness or ECU.
But it's not impossible that you have a 2nd cooked swirl port motor...
Thanks for your reply. I have cleared the code a few times but it appears again immediately.
Well done on the oil leak repair. How many hours did it take?
I estimate that it took me c.10hrs to strip it down, I would have spent c.4 hours cleaning intake manifolds and port holes and about 5 hours to reassemble. This was done over a few days. I did have a fuel leak after reassembly which was an o-ring on top of one of the injectors which did take some additional time to source.
I would advise anyone who wants to complete this task to take photos on their camera phone of each area before they strip it down, it will be worth it on reassembly as there are a lot of fuel lines, hoses etc which may become confusing to those of us not looking into these engines on a daily basis.
For what its worth replace all gaskets and o rings that you remove, the cost of these are minimal compared to have to source a leak again. I was lucky with my leak on reassembly as it was on top of the engine but I was sickened to initially see a drip from underneath the vehicle as I thought initially it may have been coolant, the thought of having to strip it down again is not worth bearing!
I have identified the problem with the swirl flap actuator. The actuator is working and is getting power. The reason I am getting the fault code is the because it is over traveling and I need to stop it doing this as it gets stuck when its fully extended. Does anyone know of a fix for this?
Since you upgraded the swirl linkage rods and flaps seemed to operate well, the only thing that comes to mind is the retaining clips on the levers.
Assuming you replaced them as well (seems like you've been very thorough), perhaps one or two broke or came off?
Oh yes, did the rod kit come with new bushings for the arms? They can wear out unevenly.
I say because I've come to appreciate Just How Fiddly this powertrain is, having just replaced 2 injectors 2 weekends ago.
The fuel return lines on the injectors are Really Good at not sealing the o rings.
I've replaced all 6 o rings twice between doing the job and coming back after, to run down the leaks. And still have fuel leakage and odor coming off the motor. I didn't have time this weekend to address it yet...
I had a new return line but didn't put it on, because the current one looked good to the eye and locked/unlocked smoothly.
I guess somehow one or more of the circle clips isn't pulling its tiny o ring back up against the lips to seal.
Be very suspicious of any black plastic bits. I'm thinking I need to replace the line, just to make the o rings happy.
It's madness / O-ring hell.
Stuttgart is oblivious, and never heard of the Challenger accident.
(Actually, they're not - they'll sell you parts all day! Everything mentioned is considered a wear item / replace, I'm sure - that's why dealership will only replace the entire manifold assemblies)
Resistor mod still would 'fix' it quicker than anything else
Good luck!
Since you upgraded the swirl linkage rods and flaps seemed to operate well, the only thing that comes to mind is the retaining clips on the levers.
Assuming you replaced them as well (seems like you've been very thorough), perhaps one or two broke or came off?
Oh yes, did the rod kit come with new bushings for the arms? They can wear out unevenly.
I say because I've come to appreciate Just How Fiddly this powertrain is, having just replaced 2 injectors 2 weekends ago.
The fuel return lines on the injectors are Really Good at not sealing the o rings.
I've replaced all 6 o rings twice between doing the job and coming back after, to run down the leaks. And still have fuel leakage and odor coming off the motor. I didn't have time this weekend to address it yet...
I had a new return line but didn't put it on, because the current one looked good to the eye and locked/unlocked smoothly.
I guess somehow one or more of the circle clips isn't pulling its tiny o ring back up against the lips to seal.
Be very suspicious of any black plastic bits. I'm thinking I need to replace the line, just to make the o rings happy.
It's madness / O-ring hell.
Stuttgart is oblivious, and never heard of the Challenger accident.
(Actually, they're not - they'll sell you parts all day! Everything mentioned is considered a wear item / replace, I'm sure - that's why dealership will only replace the entire manifold assemblies)
Resistor mod still would 'fix' it quicker than anything else
Good luck!
Yes the easy option would be to just stick in the resistor, I replaced the link rods, bushing and clips on the actuator and invested time in trying to get it right so I wanted to get to work before the resistor method. The only thing I didn't interfere with was the adjustment on one of the link arms attaching to the actuator.
Resistor mod still would 'fix' it quicker than anything else
Good luck!
Put in resistor and no fault code working perfectly. The one downfall is the high rate of fuel consumption it appears to be at least 20% higher than before, would this be correct assuming the fuel economy indicator is accurate?
> The reason I am getting the fault code is the because it is over traveling and I need to stop it doing this as it gets stuck when its fully extended. Does anyone know of a fix for this?
Wow, 20% is a big number.
Does fully extended mean 2nd inlet port each cylinder is closed (when the linkage sticks)?
I would think with ports stuck shut the mileage would be okay around town if driven moderately but suffer badly on freeway.
If ports were held open all the time I would think only effect would be idle and throttle-off transitions (and therefore emissions).
I wonder if the ports are different from one bank to the other, you were pretty meticulous!
> The reason I am getting the fault code is the because it is over traveling and I need to stop it doing this as it gets stuck when its fully extended. Does anyone know of a fix for this?
Wow, 20% is a big number.
Does fully extended mean 2nd inlet port each cylinder is closed (when the linkage sticks)?
I would think with ports stuck shut the mileage would be okay around town if driven moderately but suffer badly on freeway.
If ports were held open all the time I would think only effect would be idle and throttle-off transitions (and therefore emissions).
I wonder if the ports are different from one bank to the other, you were pretty meticulous!
The ports are fully open 100%. The driving I am doing since I have it up and running are short drives. I see a big difference in acceleration and the noise from the turbo etc, all way smoother and running much better. The only drawback is the fuel consumption. I am only going on what my fuel economy indicator is telling me but I tested this before Xmas with a full tank of fuel and it was pretty accurate. I was getting around 28 mpg and this is now at around 23 mpg.
12-29-2020, 02:27 PM
