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Centrifuge Oil leak? Repost

130K views 49 replies 18 participants last post by  westlabsauto  
#1 ·
My 2006 C230 has a slow oil drip from what my maintenance manual refers to as a centrifuge (at the rear of the right cylinder head). The oil drips on to the right exhaust at slow driving speeds and you can smell it inside the car. At highway speeds, there is no problem with smell. I am very mechanically inclined and I am wondering exactly what this centrifuge does in this case. It looks like it should be fairly easy to remove, but what parts are inside this piece? The manual does show to remove the air hose prior to centrifuge removal. There are no other problems with this car at 45k miles and we absolutely love it. Any assistance/suggestions are greatly appreciated. Thanks in advance.

Are there actually any moving parts or is this some type of fixed vane piece of equipment?
 
#2 ·
Could you post a photograph of this "centrifuge" as I'm confused what exactly you're talking about.
 
#3 ·
I don't have a picture, but it appears to be a black plastic cover on the rear of the right cylinder head. There is a black air hose that is attached to it and goes across the rear of the engine, I'm not sure where it attaches on the other end. I have a Chiltons Repair/Maintenance Manual and it says to remove the air hose prior to centrifuge removal. It looks like it would be easy to remove, but I don't want to remove it unless I know more about what is inside. I have done lots of repairs on various types of engines, but I have never come across anything like this. It's not any rush, but I eventually want to remove it to either replace the gasket or use a gasket sealer in order to stop the oil leak. Thanks for any help you can give.
 
#4 ·
Dealer reply

MB of Austin tells me that this is an oil separator and that there is a Technical Bulletin to address leaks from this area. They add that I might also need expansion plugs. Anyone else know anything about this? They are going to get back with me, so I will forward anything I find out.
 
#5 ·
Yes, it's the oil separator... It tends to fill up over time, and will start leaking. I suggest cleaning it out thoroughly.
 
#6 ·
It has no moving parts, and basically just sends the crank blow off through a circular design that acts as a centrifuge.
 
#7 ·
So if it has no moving parts, are there any removable parts, or does it come off as one piece? Also, is there a gasket that needs to be replaced, or can gasket sealer be used?
I'm also curious about the expansion plugs, is that like a freeze plug? If this is something that just needs to be cleaned out, I don't think it is necessary to take it to a MB mechanic. Any other thoughts are welcomed, I am mechanically inclined, so I am thinking about doing this myself. Thanks.
 
#8 ·
It's all one solid piece, or at least on the M111 engine in my 02' Sportcoupe it was. Where exactly is it leaking from? Again, if you can get some photographs that would really help...
 
#9 ·
It is leaking from the bottom, looks like it's coming from between the mating surfaces, but it's kind of hard to tell. I've looked at it from the bottom, and it's really slow, but at slow speeds, you can smell it when it drips onto the exhaust pipe. Any pointers, or is that the only place it can leak from?
 
#10 · (Edited)
Found something for you... I would assume the centrifuge cap has a gasket that can be replaced.
 

Attachments

#12 ·
Yes, it should work just fine... I would check with the dealership for a replacement gasket first though.
 
#14 ·
The following is the message I received from the Dealership:

1st e-mail
I am going to try to help as much as I can, but without a technician looking at your car we don't know for sure how to exactly answer your questions.

Attached are documents showing the parts breakdown and part numbers for this oil separator, which you called a centrifuge. The part number has change 3 times, there is no separate gasket, and depending on engine number it may require different covers and screws. The function of this separator is to condense the oil back out of the crankcase vapors, so it is always swimming in oil internally. Also there is a document discussing oil leaks from the plugs next to this oil separator.

Your car needs to be looked at to give any kind of precise estimate. The parts department could quote parts prices, but they’d need a VIN number to do this. I know getting service questions answered over email isn't really helpful. I hope this helps...good luck!


2nd e-mail


I talked to parts and with the information you gave us and the repairs we think you need it may consist of this:
If the hose need to be replaced (Also called the part Load vintilation hose)= 37.80
The cover on the back of the centifuge= 77.00
Cam seals on back of centrifuge to cove ports to camshafts= $6 a piece (there are 3)
Again, you might need only one of these parts or all of them. We don't know because we haven't actually looked at your C230. Scheduling an appoint with the service department is very easy and they will be able to work around your schedule to make it convenient for you. This is our number, 888-347-9568, just ask for the service department. We look forward to hearing from you.


So that's what they say so far, what do you think?
 
#15 ·
I'm wondering if the cap itself has a built in gasket... I would take the centrifuge cap off to examine it. You can always order a new cap, and if it doesn't have a gasket just return it. I'm more leaning towards making your own gaskets now. While your in there replace the cam seals to be on the safe side. Being that they are a cheap part. However, have you located the exact place it's leaking from? I know you said it "appears" to be leaking where the centrifuge joins the engine block.
 
#16 ·
As much as I hate to do it, since I don't know how the cam seals are installed, I am planning on taking it to the Dealer in Austin for them to look at it. I am going to ask for the parts that are replaced so that I can have a better idea in the future. This way, I'll know how the cover is sealed, etc. Thanks for your input.
 
#19 ·
Did you have the same problem that I'm describing? I was sure that I could replace it myself, but the dealer in Austin started bringing up all of these other possibilities that the leak could be coming from. I'm positive that it is coming from the separator cover.

Also, where is the Dealer in San Antonio? We go there pretty often, and I would just as soon go there and get the part and do it myself than go to Austin and get taken for everything they can get. Especially since they gave me a list of what it "might" be. Thanks for your help!
 
#20 ·
As they told you the inside of the centrifuge is always saturated in oil... So it's safe to assume it is leaking because the gasket on the cap gave out. If you don't want to replace the cam seals, not knowing what exactly to do, I would also assume they are still in good condition as they are constantly in oil. Really no chance to dry up, and harden...
 
#21 ·
I am going to locate a centrifuge cover and do it myself. If I can find the MB in San Antonio that bmwdad used, that's where I am going to go, because Austin MB gives me the impression that they don't really want me to try and do this myself. I have tried to talk with them before and I always seem to get an arrogant answer. bmwdad, can you give me more specific directions to your stealership, as I am coming from La Grange (east). Thanks to everyone.
 
#23 ·
Doesn't look like much room to work with. Think you'll be able to get at those star bolts?
 
#26 ·
Well, I picked up the centrifuge cover from Mercedes of San Antonio for a little over $80, but while I was there, I also got a Mann oil filter for $15. I'm planning on doing this Monday morning, so I'll let you know how it goes. I plan on keeping the old cover and reuse it with Hi-temp RTV if needed.