ot1

2006 CDI, 648, part number 6460101462. Oil is pooling at the bottom of the oil filler opening in the tray. On YouTube there is a guy who had the same problem changed out the large O ring and the smaller O ring but in the comments he states it didn’t fix the problem.
Does anyone know the OEM manufacture of the oil separator? Has Anyone changed out the rubber diaphragm that is available on eBay? I can’t find any instructions on how to do it and if that will cure the problem.

mtrevelino

I changed mine last March. I was getting an oil vapor smell in the cabin. It was wet with oil around it. I purchased a new one from RM European auto parts. It was $85. It took a couple of weeks for the smell to go away and for the oil to stop leaking. My indie said that it probably took some time for all the oil to drain out of the tubes around the oil separator.
Mike T.

rocky472

Buy the MB part. I had the same problem with my OM648. You will need to remove the tray under the air filter and clean. Also take a look at the catalyst. There is a drain hole in the tray that is directly above the catalyst. I tried an aftermarket which had bad plastic welds and leaked from the top of the chambers. Thankfully Pelican gave me a credit which I used for other parts. There are many MB dealers that discount parts so shop around for the best price. I have used Suburban MB in Ann Arbor MI and Keys MB in Van Nuys CA. The cost difference was negligible and I have been leak free for the past year.

ot1

so you replaced the oil separator as a whole unit with an MB part, do you recall the mfg of the crappy aftermarket part?

ot1

Does anyone have experience replacing just the rubber diaphragm in the circular section of the Oil separator housing? I am not referring to the O-rings others have replaced but failed to stop the leak.

so far I have only replaced the oil fill cap.