Youre prolly the highest mileage here

 

Rear Main Seal Failure Report – Mercedes-AMG GT 63 S

• Year: 2019
  
• Model: Mercedes-AMG GT 63 S 4-Door Coupe
  
• Engine Code: M177 (LS2)
  
• Mileage at Time of Failure: 72,000 miles
  
• Style/Frequency of Driving: Unknown – I am the second owner
  
• Original Owner: No – I am the second owner
  
• Did the Failure Occur Before or After Warranty Expired? After warranty expired
  
• Has it Re-leaked After Repair? Not yet repaired
  
• Cost to Repair: Not yet repaired – planning to fix it at an official Mercedes dealership
  
• Who Repaired It: Planning to repair at an authorized dealership
  
• Additional Notes:
  
  • I do not know how the previous owner drove the vehicle
    
  • The car was parked and not driven for 7 months
    

 

My car was parked for 6 months getting repaired (2019 s63 sedan) Shortly after I saw a leak on the garage floor. Took it to dealership and they changed rms and oil separators. Luckily had warranty. Cost was around 10 grand unfortunately. Do you see any leaks on floor?

 

Yes, I do see oil leaking — but only after removing the underbody shield. The engine oil collects on the cover beneath the transmission, so it’s not immediately visible on the floor. I cleaned the area several times and drove the car, but the oil kept coming back. I'm in Ukraine and still trying to resolve the issue. The dealer confirmed it's likely the RMS, but they’ll only be sure after removing the transmission.

 

You dont need to remove the transmission to see the leak, just the part where the engine and transmission meet, you'll see the seal leaking. If they do confirm it's the rear main seal, you will also need to replace the OVS else the issue will come back. Good luck, most of us here have gone through the trouble.

 

The cost to repair mine was close to $20,000, but it was covered by the warranty. About $7,500 of that was replacement of the alternat or-starter and control unit for it, as both were drenched/soaked in motor or oil. That also includes replacing the failed motor and transmission mounts. While they had the engine out, I also had them replace the thermostat, and that cost me $1,500.

 

Had my engine/trans mount replaced soon afterwards. Originally replaced the rms and ovs. Wonder if I should've mentioned the thermostat/alternator? Any signs those are failing? I recently saw some oil on the underpan of my car after the rms repair. Wonder if it's that or the transfer case leaking. Not sure. Car runs fine, no leaks on the floor.

 

Is it safe to assume the OVS is the overhead valve seal?

 

oil vapor separators

 

"Where exactly is the OVS (Oil Vapor Separator) located, and does it require removing the engine to replace it

 

In the engine compartment and I believe you do not need to remove engine. Rear Main Seal does need a transmission removal.

 

Are there any additional recommendations or steps I should take during the repair?How can I properly test the car after the job is done to make sure the leak won’t return?I’m very concerned about this issue and want to ensure it’s fully resolved.

 

When the OVS units get clogged it actually creates excess vacuum that sucks the seals in, then they leak. You can attempt to change the OVS units but it is a big job because a lot of the front of the motor needs to be removed to gain access to the units. This includes the fan, radiator, charge air coolers and several AC lines. It is not a simple job.

 

There are two at the front of the engine. Yes, the engine has to be removed and there's a lot of disassembly to get to them.

 

My understanding is the engine doesn't need to be pulled, just a disassembly of a lot of the front of engine parts (radiators, belts, fans, etc).

 

this

 

Seems like this is common to the V8s. Anyone know if a possible issue on the M256? Need to be aware what to watch for. Thanks!!!

 

m17x engines so far and mostly m177 and mostly the m177 LS2 (in the e63)

m256 has its own issues but this isn't one of them so far; this is all plenty discussed in the threads linked in the sticky

 

Most egregious issue with the M256 is deteriorating engine wire harness. It's the mid-90s all over again with Mercedes and dissolving wire harnesses.

 

Already had the harness repair done at 48k, so I guess I don’t have that hanging over me unless it happens again down the line. I’ll be watching it closely though.

But I don’t want to hijack the thread so back to the RMS issue. Glad that’s not a concern to have for me. Sounds like a real PIA. Looks like most posts here got it covered under warranty but I feel for those that have to pay some serious repair bills. And it sounds like the OVS can clog again, or did they at least update the parts?

 

parts updated but remains tbd if it holds out over time ....

 

I thought fidelity stopped covering AMG cars a couple years ago, evidently not.

 

^ They would not cover pre-2020 E63s when I inquired a few weeks ago.

 

Correct. Fidelity won't cover pre 2021
e63S

existing contracts will be honored, from what I heard.

 

Would they quote a 2019 s63?