2018 E63s RMS leak prevention
Thread Starter
Junior Member
Joined: Nov 2021
Posts: 24
Likes: 20
From: New Jersey
2018 E63s Edition 1
2018 E63s RMS leak prevention
Hey all. I’m sure we are all aware of the faulty real main seal’s and the nightmare that it is. I have an 18 e63s with about 32k miles. I wasn’t able to find out if previous owner had the seal replaced as well as the oil separators, however I’m trying to see if there’s a way to prevent it from leaking oil and wanted to see if anyone had any good insight. Changing oil separators ? Frequent oil changes ? I also saw a company who makes oil catch cans that swear it prevents from causing a faulty rear main seal. As always, much appreciated!
Super Member
Joined: Mar 2009
Posts: 657
Likes: 119
From: Boston
2020 E63s Wagon, 2012 C63 AMG Coupe, 1989 560SL, 2023 911 Carrera T
Some have installed the catch cans, so with time we'll learn if that helps at all. In theory it should. I put a catch can on my C63 M156 back in the day so I would also probably do it to the E but just have not gotten around to ordering the parts, these days my tendency is to leave things stock if I can help it.
I have seen some do the preemptive oil separator replacement, I would consider that as well but I don't think we've determined yet that it will fully fix the issue.
Keeping up with oil service probably can't hurt.
At this point, the main steps I have been taking with my own car is just to make sure my drives are long enough to warm the car up, and do some hard driving in sport+ every now and then, Italian tune up style. Have had my car a year now and added 12k miles now in the 40s, no issues yet so keeping my fingers crossed.
I have seen some do the preemptive oil separator replacement, I would consider that as well but I don't think we've determined yet that it will fully fix the issue.
Keeping up with oil service probably can't hurt.
At this point, the main steps I have been taking with my own car is just to make sure my drives are long enough to warm the car up, and do some hard driving in sport+ every now and then, Italian tune up style. Have had my car a year now and added 12k miles now in the 40s, no issues yet so keeping my fingers crossed.
Thread Starter
Junior Member
Joined: Nov 2021
Posts: 24
Likes: 20
From: New Jersey
2018 E63s Edition 1
Some have installed the catch cans, so with time we'll learn if that helps at all. In theory it should. I put a catch can on my C63 M156 back in the day so I would also probably do it to the E but just have not gotten around to ordering the parts, these days my tendency is to leave things stock if I can help it.
I have seen some do the preemptive oil separator replacement, I would consider that as well but I don't think we've determined yet that it will fully fix the issue.
Keeping up with oil service probably can't hurt.
At this point, the main steps I have been taking with my own car is just to make sure my drives are long enough to warm the car up, and do some hard driving in sport+ every now and then, Italian tune up style. Have had my car a year now and added 12k miles now in the 40s, no issues yet so keeping my fingers crossed.
I have seen some do the preemptive oil separator replacement, I would consider that as well but I don't think we've determined yet that it will fully fix the issue.
Keeping up with oil service probably can't hurt.
At this point, the main steps I have been taking with my own car is just to make sure my drives are long enough to warm the car up, and do some hard driving in sport+ every now and then, Italian tune up style. Have had my car a year now and added 12k miles now in the 40s, no issues yet so keeping my fingers crossed.
Junior Member
Joined: Sep 2025
Posts: 32
Likes: 21
From: Peachtree City GA
2019 E63S Wagon
Based on all the research I've done, as well as my personal experience and solution on my wagon - on the older cars (pre-2020?), the solution is to replace the OVSs with the newer design before they clog up and cause the RMS to blow out.
The issue is that if you plan to use an extended warranty or service plan to cover the cost, you will need to demonstrate some kind of damage or show evidence of an active oil leak. If you are ok paying out of pocket to prevent future issues...then just go for it!
The issue is that if you plan to use an extended warranty or service plan to cover the cost, you will need to demonstrate some kind of damage or show evidence of an active oil leak. If you are ok paying out of pocket to prevent future issues...then just go for it!
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Joined: Jul 2013
Posts: 2,594
Likes: 811
From: Toronto, Ont, Canda
go fast grocery getter wagon
For my 18, i changed oils at 7500-8000km intervals and have RMS leak at around 100,000km still. Thus, no conclusive evidence suggests RMS leak will not happen with frequent oil changes
Thread Starter
Junior Member
Joined: Nov 2021
Posts: 24
Likes: 20
From: New Jersey
2018 E63s Edition 1
Based on all the research I've done, as well as my personal experience and solution on my wagon - on the older cars (pre-2020?), the solution is to replace the OVSs with the newer design before they clog up and cause the RMS to blow out.
The issue is that if you plan to use an extended warranty or service plan to cover the cost, you will need to demonstrate some kind of damage or show evidence of an active oil leak. If you are ok paying out of pocket to prevent future issues...then just go for it!
The issue is that if you plan to use an extended warranty or service plan to cover the cost, you will need to demonstrate some kind of damage or show evidence of an active oil leak. If you are ok paying out of pocket to prevent future issues...then just go for it!
Junior Member
Joined: Sep 2025
Posts: 32
Likes: 21
From: Peachtree City GA
2019 E63S Wagon
I only replaced the left and right PCV/Oil-Vapor Separators. I'm not sure if they needed any additional clamps, etc to install them.
The shop that did mine didn't have to drop the engine or pull the entire front-end off the car.
The technician's notes from the invoice are:
Confirmed leak present from rear main seal. Xentry tip LI01.40-P-079518 requires replacement of air/oil separators & degreasing when repairing leak from seal. Requires LOF and drain/refill cooling system as well.
- Oil Separator - Mercedes-Benz - 177-010-87-12
- Oil Separator - Mercedes-Benz - 177-010-88-12
if you are feeling froggy - check this thread out - drrckh11 did the job himself...he has some great photos of what's involved to give you a feel for the scope of the job.
https://mbworld.org/forums/w213-amg/...m_content=post
Last edited by sir_tbizzle; Apr 11, 2026 at 10:47 AM.
