RMS Leak Part 2
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MBWorld Fanatic!
Joined: Nov 2015
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
RMS Leak Part 2
I still have no leak in my RMS after MB of Seattle replaced it last spring but I went to add a quart of oil to the motor as it was down a little bit and with the car running I literally could not remove the oil fill cap. There was so much vacuum that it was stuck to the filler. I went back and forth with MB of Seattle on the OVS when they did the RMS and they swore up and down that they were fine. Clearly they are not as this should not be happening. I am kind of done with them unless the RMS starts to leak again as it has a 2 year MB warranty on it but now I am going to have to take it to my Indy and have the OVS units replaced. Should still be covered under my Fidelity warranty but it is just ridiculous that they have to rip the front of the motor apart again to replace these things when they should have been done while the entire drivetrain was out. Oh well. I guess it is better to get it done now under warranty than have it blow something up once I am out of warranty.
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From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
I still have no leak in my RMS after MB of Seattle replaced it last spring but I went to add a quart of oil to the motor as it was down a little bit and with the car running I literally could not remove the oil fill cap. There was so much vacuum that it was stuck to the filler. I went back and forth with MB of Seattle on the OVS when they did the RMS and they swore up and down that they were fine. Clearly they are not as this should not be happening. I am kind of done with them unless the RMS starts to leak again as it has a 2 year MB warranty on it but now I am going to have to take it to my Indy and have the OVS units replaced. Should still be covered under my Fidelity warranty but it is just ridiculous that they have to rip the front of the motor apart again to replace these things when they should have been done while the entire drivetrain was out. Oh well. I guess it is better to get it done now under warranty than have it blow something up once I am out of warranty.
Tonight I went through a zoning, planning, concept plan meeting and was approved for a final project. It took us three weeks to prepare before the meeting, no lawyers, architect, or others were used or paid for service. We simply smother the officials and honey and let them know exactly what we needed and told them we would do exactly as they asked and they took a 4 to 6 month project and turned it into a 15 minute meeting… Sometimes a good strategy can get things done. For those of you that know about construction projects, this type of result is almost unheard of without strong connections and payoffs.
So, see if you can make someone else fight the fight for us. Personally think Osv should be covered by emissions warranty, and I think there should be a forced federal recall for their non compliance… but I also feel this way for anybody that has also lost startup noise due to re-coding because Mercedes was likely cheating at emissions with that process as well.
good luck…what a pain
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
I remember @superpop fighting both Fidelity and MB of Seattle to change the OVS at the time of the oil valve failure, especially since they had to removed the eintre motor along with the subframe from the car. It made too much sense to not do it at that time. I'm curious to see if they will cover replacing the OVS prior to it causing an oil leak. If I remember correctly, the OVS tested fine with the vacuum gauge at the time of the prior repair; I wonder if there's a test procedure that wasn't followed proplerly at that time.
In any event, I wish you the best of luck!
In any event, I wish you the best of luck!
Last edited by carlosinseattle; Jan 7, 2026 at 02:42 PM.
Thread Starter
MBWorld Fanatic!
Joined: Nov 2015
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
I remember @superpop fighting both Fidelity and MB of Seattle to change the OVS at the time of the oil valve failure, especially since removed the eintre motor along with the subframe from the car. It made too much sense to not do it at that time. I'm curious to see if they will cover replacing the OVS prior to it causing an oil leak. If I remember correctly, the OVS tested fine with the vacuum gauge at the time of the prior repair; I wonder if there's a test procedure that wasn't followed proplerly at that time.
In any event, I wish you the best of luck!
In any event, I wish you the best of luck!
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Joined: Apr 2021
Posts: 1,568
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From: Scottsdale, Arizona
2001 E55AMG
Funny enough I had either the owner of this dealer or one in the area reach out to me for Fidelity warranty on his S65 AMG coupe... Now why would the owner of a Mercedes-Benz dealer, who I'm sure gets repairs at cost or -$0 after taxes, and has their own warranty coverage offerings, be reaching out to ME for warranty coverage off his own book, very suspicious... I never replied.
OVS will be replaced with provable failure, it has been covered many a time to our Fidelity customers.
Trenton O. Gibson
tgibson@highline-autos.com
Highline Autos
Direct: 602.909.9216
Office: 480.348.0777
OVS will be replaced with provable failure, it has been covered many a time to our Fidelity customers.
Trenton O. Gibson
tgibson@highline-autos.com
Highline Autos
Direct: 602.909.9216
Office: 480.348.0777
Thread Starter
MBWorld Fanatic!
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
Got the car back today and I am very glad to have this behind me. I just knew those OVS cases where clogged and it felt like I was driving around with a hand grenade with the pin pulled. Fidelity did cover around 95% of the cost and was easier to work with on this go around. While they were in there I had them do both serpentine belts as I am now at around 49K miles and I would have wanted to do them at 60K. Indy told me I saved a bunch doing it now as they already had the charge coolers off. I had them keep all the parts as I am going to do a YouTube video on the symptoms of this and then seperate the OVS units and see how they work and how they might clog. Belts looked fine and the mechanic said that the pulleys and tensioners all looked and sounded great. Should be good for a while now. I think I am up to around 15K in claims with Fidelity now so in my case the ELW was worth every penny. I am starting to wonder if my car was just built on a Friday.
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
Congrats on getting your car back!! It sounds like you had your indy do all the work this time, right? What test did they perform to show that the OVS weeren't functioning properly? I'd love to know how to perform that test on my car someday.
Also, on the W213 forum they posted the updated TSB on RMS leaks. MB now calls for changing out the OVS, then rechecking for RMS leak. If no leak, they send the car home WITHOUT changing the RMS. One guy had that done on his E63 a few months back and is happy with the results. Here's the TSB for anybody who hasn't seen this yet: https://static.nhtsa.gov/odi/tsbs/20...20807-0001.pdf
Also, on the W213 forum they posted the updated TSB on RMS leaks. MB now calls for changing out the OVS, then rechecking for RMS leak. If no leak, they send the car home WITHOUT changing the RMS. One guy had that done on his E63 a few months back and is happy with the results. Here's the TSB for anybody who hasn't seen this yet: https://static.nhtsa.gov/odi/tsbs/20...20807-0001.pdf
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Thread Starter
MBWorld Fanatic!
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
No particular test, it was very obvious just by running the car and trying to remove the oil fill cap while the car was running. You literally could not remove the cap with the car running. Now it has a very subtle vacuum which he said was normal for this motor when the OVS units are not clogged. Will be interesting to crack the old ones open and see what is going on.
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MBWorld Fanatic!
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From: Phoenix
222 S-65
No particular test, it was very obvious just by running the car and trying to remove the oil fill cap while the car was running. You literally could not remove the cap with the car running. Now it has a very subtle vacuum which he said was normal for this motor when the OVS units are not clogged. Will be interesting to crack the old ones open and see what is going on.
MBWorld Fanatic!
Joined: Feb 2017
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From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
I’d also live to see photos. From what I’ve seen posted around the net it is going to be the O-rings on the little valves or the valves that go into the engine.
I would personally like to see one opened up to see how those parts are sticking or clogging and I’d like to see you send an intake cleaner through another one to see if that helps unclogged the sticking valves…
i’ve continuously wondered if this is an item that can be cleaned from the inside with a mist, though that would not help with the **** quality O-rings that they spec them with.
looking forward to see what you find and glad you’ve got the car back running well.
I would personally like to see one opened up to see how those parts are sticking or clogging and I’d like to see you send an intake cleaner through another one to see if that helps unclogged the sticking valves…
i’ve continuously wondered if this is an item that can be cleaned from the inside with a mist, though that would not help with the **** quality O-rings that they spec them with.
looking forward to see what you find and glad you’ve got the car back running well.
Out Of Control!!
Joined: Sep 2018
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From: unbegrenzt
2017 GLE350 4MATIC
FWIW Porsche (VAG) vee engines run 150mbar crankcase vacuum at idle. It is hard to get the oil fill cap off. A rennlister measured his crankcase vacuum on Cayenne and it was 160mbar, close enough to the spec given normal measurement variation. MB is going to be in a similar situation as VAG. They all use the same engineering consulting companies FEV and AVL.
Thread Starter
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
Pasted this from the W213 forums as it is applicable here as well. If you have not had your OVS done yet this settlement may apply to you. I just filed a claim for my recent repair but may not be eligible because my work was not done at an MB authorized dealer. Don't make that mistake as it sounds like if you take your vehicle in now and have them do the OVS they may cover it with this settlement.
I was reading Autoblog and came across this: Emissions Warranty settlement. It links to the actual settlement: Hazdovac Emmissions Warranty Settlement Basically they will reimburse for up to 100% of repair, diagnosis, and replacement for qualified claims. You must have purchased or leased the vehicle in California or states that follow California's emission and pollution regulations. Parts that are covered include:
Manifold PCV Connection Assembly
Power Train Control Unit (PCM)
Accelerator Pedal Sensor
Accelerator Pedal
Partial Load Operation Crankcase Ventilation Valve
Clean Air Line
Pressure Sensor Downstream of Air Filter
Check Valve within the EVAP System
Crankcase Ventilation System
Vent Control Valve
Charcoal Canister
Fuel Tank Level Indicator Fill Level Sensors
Coolant Thermostat
ESP Electronic Stability Program Control Unit
Looks like some RMS failures should be covered.
I was reading Autoblog and came across this: Emissions Warranty settlement. It links to the actual settlement: Hazdovac Emmissions Warranty Settlement Basically they will reimburse for up to 100% of repair, diagnosis, and replacement for qualified claims. You must have purchased or leased the vehicle in California or states that follow California's emission and pollution regulations. Parts that are covered include:
Manifold PCV Connection Assembly
Power Train Control Unit (PCM)
Accelerator Pedal Sensor
Accelerator Pedal
Partial Load Operation Crankcase Ventilation Valve
Clean Air Line
Pressure Sensor Downstream of Air Filter
Check Valve within the EVAP System
Crankcase Ventilation System
Vent Control Valve
Charcoal Canister
Fuel Tank Level Indicator Fill Level Sensors
Coolant Thermostat
ESP Electronic Stability Program Control Unit
Looks like some RMS failures should be covered.
Member
Joined: Feb 2026
Posts: 103
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I've been following this discussion, my 22 GLS has this issue and I had to do the software update to get rid of the leak, also made sure the drain was working properly by manually checking and cleaning it out, seems to have fixed the issue for me.
Member
Joined: Feb 2026
Posts: 103
Likes: 12
yup, my experience with the RMS leak on my 2022 GLE has been a real pain, I've had to drain the system and clean the pump multiple times, but still getting a slow leak, gonna have to try the new seal kit that just came out.
MBWorld Fanatic!
Joined: Aug 2007
Posts: 1,825
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
Pasted this from the W213 forums as it is applicable here as well. If you have not had your OVS done yet this settlement may apply to you. I just filed a claim for my recent repair but may not be eligible because my work was not done at an MB authorized dealer. Don't make that mistake as it sounds like if you take your vehicle in now and have them do the OVS they may cover it with this settlement.
I was reading Autoblog and came across this: Emissions Warranty settlement. It links to the actual settlement: Hazdovac Emmissions Warranty Settlement Basically they will reimburse for up to 100% of repair, diagnosis, and replacement for qualified claims. You must have purchased or leased the vehicle in California or states that follow California's emission and pollution regulations. Parts that are covered include:
Manifold PCV Connection Assembly
Power Train Control Unit (PCM)
Accelerator Pedal Sensor
Accelerator Pedal
Partial Load Operation Crankcase Ventilation Valve
Clean Air Line
Pressure Sensor Downstream of Air Filter
Check Valve within the EVAP System
Crankcase Ventilation System
Vent Control Valve
Charcoal Canister
Fuel Tank Level Indicator Fill Level Sensors
Coolant Thermostat
ESP Electronic Stability Program Control Unit
Looks like some RMS failures should be covered.
I was reading Autoblog and came across this: Emissions Warranty settlement. It links to the actual settlement: Hazdovac Emmissions Warranty Settlement Basically they will reimburse for up to 100% of repair, diagnosis, and replacement for qualified claims. You must have purchased or leased the vehicle in California or states that follow California's emission and pollution regulations. Parts that are covered include:
Manifold PCV Connection Assembly
Power Train Control Unit (PCM)
Accelerator Pedal Sensor
Accelerator Pedal
Partial Load Operation Crankcase Ventilation Valve
Clean Air Line
Pressure Sensor Downstream of Air Filter
Check Valve within the EVAP System
Crankcase Ventilation System
Vent Control Valve
Charcoal Canister
Fuel Tank Level Indicator Fill Level Sensors
Coolant Thermostat
ESP Electronic Stability Program Control Unit
Looks like some RMS failures should be covered.
Thread Starter
MBWorld Fanatic!
Joined: Nov 2015
Posts: 1,687
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From: Newcastle, WA
2019 S63 4Matic+, 2018 E400 Cabrio, wardens car.
