Preventative measures - oil separators | valve cover seeal

Aug 13, 2025 | 10:17 PM

Triatica2

Thread Starter

Newbie

Joined: Jun 2025

Posts: 6

Likes: 1

From: Sammamish, wa

2020 S560

Preventative measures - oil separators | valve cover seeal

Folks, at the risk of duplicating material in multiple threads, I am:

Aware that I need to watch out for oil puddling around the spark plugs, as a result of….
Leaking through the valve cover seal, as a result of…
Clogged oil separators building excessive crankcase pressure which pushes through the elastomeric valve cover seal.

My questions are:

My 2020 S560 4Matic I understand has the M176 engine which is prone to this problem - can anyone confirm the engine model series to the body / year combination and if this problem happens to this engine model/spec?
What can be done as preventative measures to prevent the oil separators from getting clogged up in the first place..is it just oil changes every 5k miles, or is there more?

Hopefully the answers distill the actions for an owner to the essence of prevention.

Thanks in advance…

Aug 13, 2025 | 10:45 PM

antica

Junior Member

Joined: May 2025

Posts: 35

Likes: 10

Quote:

Originally Posted by Triatica2

Folks, at the risk of duplicating material in multiple threads, I am:

Aware that I need to watch out for oil puddling around the spark plugs, as a result of….
Leaking through the valve cover seal, as a result of…
Clogged oil separators building excessive crankcase pressure which pushes through the elastomeric valve cover seal.

My questions are:

My 2020 S560 4Matic I understand has the M176 engine which is prone to this problem - can anyone confirm the engine model series to the body / year combination and if this problem happens to this engine model/spec?
What can be done as preventative measures to prevent the oil separators from getting clogged up in the first place..is it just oil changes every 5k miles, or is there more?

Hopefully the answers distill the actions for an owner to the essence of prevention.

Thanks in advance…

Experiencing this now, but I am at almost 180k miles. Car has had 0 issue since then, but then again I do all service before it is due. I make sure to get oil changes as soon or before it hits 5k. Maybe using some engine cleaner every few oil changes can help prevent this. I have only used it once when I did my first tune up.

Last edited by antica; Aug 13, 2025 at 10:47 PM.

Aug 14, 2025 | 11:13 AM

SW20S

MBWorld Fanatic!

Joined: Jun 2015

Posts: 9,051

Likes: 4,557

From: Maryland

2024 S580

The best preventative according to all the people I have talked to and all the research I have done is to do oil changes at 5k miles instead of 10k miles.

Aug 14, 2025 | 01:57 PM

carlosinseattle

MBWorld Fanatic!

Joined: Aug 2007

Posts: 1,823

Likes: 792

From: Pacific Northwest

2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan

Quote:

Originally Posted by Triatica2

Folks, at the risk of duplicating material...............
My questions are:

My 2020 S560 4Matic I understand has the M176 engine which is prone to this problem - can anyone confirm the engine model series to the body / year combination and if this problem happens to this engine model/spec?
What can be done as preventative measures to prevent the oil separators from getting clogged up in the first place..is it just oil changes every 5k miles, or is there more?

Hopefully the answers distill the actions for an owner to the essence of prevention.

Thanks in advance…

1. The OVS issues cover 2016-2021 M17X motors. M176, M177, M178, all variants of the 4.0TT. The M177 looks to be the one most affected of the 3, then the M176. But hard to say because very few M178s out there in comparison.
2. Aggressive oil change schedule, only use Top Tier gas (there are a bunch of threads about this very subject and why on the forum), and run the car at optimal temps as much as possible, meaning avoid short duration trips where the car doesn't get warmed up. Also, good long trips are great. Ironic that 2 guys who have 2019 S63's had their RMS go bad immedeately after their cars sat for 3-6 months while waiting for collision repairs, one of them lives not too far from you.

Aug 21, 2025 | 02:14 AM

Donnymac

Super Member

Joined: Aug 2013

Posts: 779

Likes: 205

From: Texas

63 Falcon vert

Especially as to operating temp, Carlos is right. The motor/fluids are designed not to run cold but hot. Making a cold motor work hard is a recipe for damage.

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