cx876

I'm looking to replace my oil separator cover(2720100631) this weekend, but I'm not sure if I should also replace the actual oil separator itself(2730100162),

when I check for instruction online 90% of the people only replace the cover, can't find much resource about replacing the actual separator,

I heard someone mention the bolt holding down the oil separator is reverse thread, so I'm kinda hesitate to work on it since if I stripped it would be a nightmare to fix.

any recommendation would be highly appreciated, the car is 2011 E350 base.

konigstiger

See attachment.

cetialpha5

There's several videos online about doing it. Basically you should inspect the oil separator to see if there are grooves in it or not. If there are grooves, replace it. You could get this kit if you just want to replace all the parts although the individual parts are cheaper from a Mercedes dealer that sells online.

https://www.fcpeuro.com/products/mer...kit-oem-515810

cx876

many thanks both of you! I already have the parts and give it a try today,
but the tools that I have couldn't reach the lowest bolt at all.

guess I'll have my indy do it next month when they replace the engine mount.

cetialpha5

If you watch the youtube video on how to do it, they basically use a bit and a vice grip clamped to it to turn the lower bolts as there isn't enough room for a regular tool.

cx876

the fasteners on my cover is external torx bolt so the bit won't work, try it with a wrench couldn't really get it into position

pb39374

yeah, it’s a pain in the a$$ to get back in there to change this if you don’t have the right tool. I gave up the first time after I scratched up my hands pretty good getting back there. I couldn’t wear gloves because I didn’t have a good feel for where things were back there. I waited about 6 months and gave it another try after buying some different tools. It was a pain, but finally got it. It’s hard to get a good feel on tightening it down to the correct torque spec when you are buttoning up the job.

TimC300

Old thread I know. But I recently replaced mine after alot of researching and planning and turned out really simple and easy. My cover has E10 bolt heads, which as you know a socket wont fit in there. I used an 8mm closed end wrench for 3 of the bolts then bought a 5/16 offset wrench specifically for the bottom outer bolt, worked perfectly. For the drip pan I used a 1/4 E8 socket with a 1/4 swivel joint adapter as an extension with my small 1/4 ratchet and it was the perfect length to reach in there while being able to fit the ratchet against the firewall. The shaft, or whatever its called, of the drip pan looked fine actually no grooves but replaced it since I already bought it. Probably didnt need to. I dont know if it was ever replaced before since I bought the car used and from the looks and carfax it was regularly service at Mercedes. Toughest part was getting that bottom outer bolt of the cover back in, had it squeezed between my fingers a certain way while moving my hand over to get it in the hole. I did drop that bolt once but luckily I happen to have the plastic undertray off below that area so it feel right to the ground and I was able to easily locate it. I had my telescoping magnet handy just in case.

nkx1

I just replaced the crank case breather and oil separator as well, since i saw a tad bit of oil on the lower threads of my spark plugs when replacing them. I also saw a bit of oil on the lower portion of the throttle body. Nothing too awful, but figured I may as well change it even though my 2010 only has like 19K miles on it.

I too had some trouble with the lower bolts on the crank case breather. But once I figured out that a 5/16 box end wrench worked, it was increadibly easy. I wish I would have known that going in!

I was hoping one of these parts was the reason for the oil on the spark plug threads, but no such luck; the crank case breather and oil separator were both in perfect condition. Oh well, I just replaced them anyway since I already bought the parts. I'm hoping the minor amount of oil on the spark plugs isn't indicative of some other a significant issue.

retna7

I found a tool that makes installing and removing the M272/M273 centrifuge cover a breeze.

Centrifuge wear at 105k miles.

TimC300

Heres the wrench I bought which worked out very well. Had to keep repositioning it on the bottom outer bolt due to limited room to swing it.




I was going to replace the drivers side cover until i realized theres nothing in it that wears, no reason to change it. Unless the gasket is leaking oil. I removed mine, cleaned it and re-installed it.

nkx1

It honestly looks like you could have cleanred off the metal portion and called it a day. Doesn't look word at all.

retna7

Agreed.

At worst: Ounce of prevention.

At best: Looking for the cause of this:





That much oil on a plug ain't pretty.

No codes, but rough idle at times.

Still drives like normal.

nkx1

Yeah, that's a lot of oil.

I mentioned this in a different thread, but my 550 (M273 engine) spark plugs seemed to have more oil on them than they should for 17K miles. Very odd. I'm pretty sure my CLK550 with 65K miles had no oil at all on the spark plugs, despite it being the same exact engine.

retna7

Right.

Not sure what the cause might be.

Valve rings are the only other thing that comes out of my research so far but that's not something I'm willing to mess around with on my own.

I thought of adding a Mann Hummel ProVent 200 catch can to see if it makes a difference but there's no room for easy access.

nkx1

Yeah, valve seals are above my pay grade for sure!

Another potential source is leaking valve cover gaskets. Not sure about whatever engine you have, but on the M273, sealant is used for the valve covers (no actual gasket) and leaking is not all that common to my knowledge. I'll just have to ask my mechanic what he thinks next time around.