Rear main seal leak impacting all M177 motors?
Out Of Control!!
Joined: Sep 2018
Posts: 14,678
Likes: 4,578
From: unbegrenzt
2017 GLE350 4MATIC
Had the thermostat go bad and throw EL. Under CPO. Shop replaced it and the oil separators under warranty.
they never mentioned the RMS. Should I bring it back and have them check it.
since I got it back the car warms much faster but I’ve noticed strange shifting (like stuck in neutral between gears when giving lots of gas) and gotten warnings about headlight low beams not working (left and right side).
any thoughts?
they never mentioned the RMS. Should I bring it back and have them check it.
since I got it back the car warms much faster but I’ve noticed strange shifting (like stuck in neutral between gears when giving lots of gas) and gotten warnings about headlight low beams not working (left and right side).
any thoughts?
Shifting behavior unrelated to OVS/RMS.
Super Member
Joined: Jun 2014
Posts: 517
Likes: 71
From: Los Angeles, CA
2019 S63 AMG (Current), 2015 E63S, 2008 E63, 2005 E55
well, it just happened to me. Thank god for the CPO extended warranty.
I brought the car in because the heat wasn’t working, and the service dept. convinced me to do spark plugs at 45k miles.
When they did the plugs, they found oil leaking from the head gasket, oil separators failed, and rear main seal failed.
All replaced, without removing the engine (looks like they took the transmission out from the bottom to get at the RMS).
anyway I’m in a W222, but it’s the S560. So I think these oil separators are just a bad design it seems. Both of mine were failed.
Guess I need to budget $10k in 5 years time to do this again out of warranty.
I brought the car in because the heat wasn’t working, and the service dept. convinced me to do spark plugs at 45k miles.
When they did the plugs, they found oil leaking from the head gasket, oil separators failed, and rear main seal failed.
All replaced, without removing the engine (looks like they took the transmission out from the bottom to get at the RMS).
anyway I’m in a W222, but it’s the S560. So I think these oil separators are just a bad design it seems. Both of mine were failed.
Guess I need to budget $10k in 5 years time to do this again out of warranty.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
https://mbworld.org/forums/w213-amg/...fixes-diy.html
Add to the database:
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Member
Joined: Jan 2019
Posts: 222
Likes: 39
GLC43 SUV
Wtf man if I was Mercedes, I would do all I could to keep a loyal client like you happy. We're talking about a real long term customer here and they offer you less than a grand discount on an issue that's widely known on one of their high tier products failing you?? Ten percent discount?? I can't get over that..... that is plain rude. Seriously.... God that just sh*ts me
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,229
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Junior Member
Joined: Apr 2025
Posts: 35
Likes: 3
AMG GT 63s
Hi everyone,
I own a 2019 Mercedes AMG GT 63 S with about 72,000 miles on the clock. Recently, I noticed some engine oil leakage in the area between the engine and transmission (gearbox).
After doing research, I came across many discussions about rear main seal (RMS) failures due to crankcase overpressure from clogged oil vapor separators (OVS) in M177- powered models, especially in E63 and G63.
Could anyone with a similar car or mileage share their experience?
Any advice or shared links would be greatly appreciated. Thanks in advance!
I own a 2019 Mercedes AMG GT 63 S with about 72,000 miles on the clock. Recently, I noticed some engine oil leakage in the area between the engine and transmission (gearbox).
After doing research, I came across many discussions about rear main seal (RMS) failures due to crankcase overpressure from clogged oil vapor separators (OVS) in M177- powered models, especially in E63 and G63.
Could anyone with a similar car or mileage share their experience?
- Is it necessary to remove the engine completely to replace the oil separators, or can it be done with just removing the transmission?
- Do you know of any videos or guides that demonstrate how to replace the OVS on this engine?
Any advice or shared links would be greatly appreciated. Thanks in advance!
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Senior Member
Joined: Dec 2025
Posts: 425
Likes: 37
From: Keep it simple - keep it OEM
AMG C63s Coupe
The oil seperator from M177 LS1 has a updated part number too … i check this by VIN (my car) & MB Parts catalogue. I have from factory the latest version .
In my mind all this oil leaks are -maybe-caused by faulty function (clogged by time) oil seperator. Overpressure in the engine causes leaks from all sorts of seals.
In my mind all this oil leaks are -maybe-caused by faulty function (clogged by time) oil seperator. Overpressure in the engine causes leaks from all sorts of seals.
Last edited by C63s_Jack; Jan 14, 2026 at 06:29 PM.
Out Of Control!!
Joined: Sep 2018
Posts: 14,678
Likes: 4,578
From: unbegrenzt
2017 GLE350 4MATIC
The oil seperator from M177 LS1 has a updated part number … i check this by VIN (my car) & MB Parts catalogue. I have from factory the latest version .
In my mind all this oil leaks are -maybe-caused by faulty function (clogged by time) oil seperator. Overpressure in the engine causes leaks from all sorts of seals.
In my mind all this oil leaks are -maybe-caused by faulty function (clogged by time) oil seperator. Overpressure in the engine causes leaks from all sorts of seals.
Newbie
Joined: May 2015
Posts: 9
Likes: 5
2019 E63s AMG
I filed with and spoke to NHTSA. They recommended everyone who has had the issue to file with them and reference the following in the complaint
NHTSA ID Number: 11020807
Manufacturer Communication Number: LI01.40-P-079518
The service bulletin was issued July 16, 2025.
I bought my car in January 2025 w 28K no issues and it was inspected at MB. B service at 42K and RMS leaks. Been back and forth with the dealership and theyve reduced the labor, but its still $6500.
If we all orgonize and file w NHTSA.gov, we got a shot at eventually getting reimbursed.
NHTSA ID Number: 11020807
Manufacturer Communication Number: LI01.40-P-079518
The service bulletin was issued July 16, 2025.
I bought my car in January 2025 w 28K no issues and it was inspected at MB. B service at 42K and RMS leaks. Been back and forth with the dealership and theyve reduced the labor, but its still $6500.
If we all orgonize and file w NHTSA.gov, we got a shot at eventually getting reimbursed.
MBWorld Fanatic!
Joined: Aug 2007
Posts: 1,830
Likes: 793
From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
Hi everyone,
I own a 2019 Mercedes AMG GT 63 S with about 72,000 miles on the clock. Recently, I noticed some engine oil leakage in the area between the engine and transmission (gearbox).
After doing research, I came across many discussions about rear main seal (RMS) failures due to crankcase overpressure from clogged oil vapor separators (OVS) in M177- powered models, especially in E63 and G63.
Could anyone with a similar car or mileage share their experience?
Any advice or shared links would be greatly appreciated. Thanks in advance!
I own a 2019 Mercedes AMG GT 63 S with about 72,000 miles on the clock. Recently, I noticed some engine oil leakage in the area between the engine and transmission (gearbox).
After doing research, I came across many discussions about rear main seal (RMS) failures due to crankcase overpressure from clogged oil vapor separators (OVS) in M177- powered models, especially in E63 and G63.
Could anyone with a similar car or mileage share their experience?
- Is it necessary to remove the engine completely to replace the oil separators, or can it be done with just removing the transmission?
- Do you know of any videos or guides that demonstrate how to replace the OVS on this engine?
Any advice or shared links would be greatly appreciated. Thanks in advance!
RMS FAIL DATABASE
Senior Member
Joined: Dec 2025
Posts: 425
Likes: 37
From: Keep it simple - keep it OEM
AMG C63s Coupe
Nice link - Database.
Lots of angry guys but non is checking the (parts) situation of fail. Thats always the first i do - check oem parts for updated parts. (replaced part number).
Clear and check cause to the ground.
But what can we see ?
Mostly LS2 fails !!!
It looks like in my fast over view MB is accommodating to MB owners with this problem ? !
There are updated MB OEM parts … the sealing (engine/transmission) and the oil seperator too ( i know that because mb parts guy show me that by VIN) …there you can see also what partnumber insert by factory build from your car too)
I think the most LS1 (C63) guys can calm down.
easy peasy
Lots of angry guys but non is checking the (parts) situation of fail. Thats always the first i do - check oem parts for updated parts. (replaced part number).
Clear and check cause to the ground.
But what can we see ?
Mostly LS2 fails !!!
It looks like in my fast over view MB is accommodating to MB owners with this problem ? !
There are updated MB OEM parts … the sealing (engine/transmission) and the oil seperator too ( i know that because mb parts guy show me that by VIN) …there you can see also what partnumber insert by factory build from your car too)
I think the most LS1 (C63) guys can calm down.
easy peasy
Last edited by C63s_Jack; Mar 14, 2026 at 06:37 AM.
MBWorld Fanatic!
Joined: Aug 2007
Posts: 1,830
Likes: 793
From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
I filed with and spoke to NHTSA. They recommended everyone who has had the issue to file with them and reference the following in the complaint
NHTSA ID Number: 11020807
Manufacturer Communication Number: LI01.40-P-079518
The service bulletin was issued July 16, 2025.
I bought my car in January 2025 w 28K no issues and it was inspected at MB. B service at 42K and RMS leaks. Been back and forth with the dealership and theyve reduced the labor, but its still $6500.
If we all orgonize and file w NHTSA.gov, we got a shot at eventually getting reimbursed.
NHTSA ID Number: 11020807
Manufacturer Communication Number: LI01.40-P-079518
The service bulletin was issued July 16, 2025.
I bought my car in January 2025 w 28K no issues and it was inspected at MB. B service at 42K and RMS leaks. Been back and forth with the dealership and theyve reduced the labor, but its still $6500.
If we all orgonize and file w NHTSA.gov, we got a shot at eventually getting reimbursed.
Maybe you can get the cost reimbursed.
