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The vapor separator failure may be time related as much as mileage related. Higher mileage in a shorter time suggests higher average engine temperature, which to my way of thinking helps separator function. A garage queen would have generally cooler average engine temp (over the long term) and oil vapor can migrate, condense and gum up the works (plug the separator). The separators have some fussy valves (overpressure or relief valves) and maybe a mesh filter or two. Perfect for getting plugged.
Removing the factory separators and replacing with an aftermarket catch can would be one option. Or opening up the MB separators and modifying the internals by removing check valves and filters. Problem is the separators appear to be blow molded plastic and these could be hard to reassemble once taken apart. Someone will figure something out.
I was at the dealer and asked them about this, they mentioned that they usually see this as an issue on cars that are babied/not driven hard now and then. They said if you Italian tune up regularly, you won't have this issue.
I was at the dealer and asked them about this, they mentioned that they usually see this as an issue on cars that are babied/not driven hard now and then. They said if you Italian tune up regularly, you won't have this issue.
I can see some logic and science in this. Italian tuneup = higher peak engine temp and more blowby flow. Helps keep the flow path through the separators from gumming up. And it's fun.
All this talk of separators and still no one has given us an idea of where these things are or how to inspect/clean/replace.
They're located at the front of the engine, accessible only after removing both the air filter housings and charge air coolers (see photo for front view of engine with those pieces removed).
In terms of inspecting them, you could push some air through them to see if they're flowing relatively freely, but i'm unsure if that would be enough to determine the condition inside of the separator.
I think smartest thing to do is to spend the few hundred dollars on a new set and replace them as part of some preventative maintenance. That's what i'll be doing in the next month or so.
2018 E63S wagon with 52,730 miles. Purchased used last month, had an issue with an oil leak, brought to dealer, at first they found it was the drain plug leaking (probably from the chevy dealer I purchased it from and them not changing the one time use drain plug when they changed the oil on it when they got it in as a trade in). Mercedes dealer swapped a new plug in and it wasn't seating correctly, tried another new plug and it made it worse where gasket where drain plug sits in oil pan was tweaked. They replaced the oil pan free of charge. Got the car back, and was still getting a small oil spot in driveway, underside was shiny and visibly oil soaked. Brought back to dealer, they got it on the lift and video from Technician shows him believing RMS is leaking. Haven't gotten any word on a quote from service advisor yet. When I brought it in yesterday and told him about lots of people having the RMS leak he seemed complexed and didn't believe it. This might be the first one they've had in for the issue.
Looking for some advice on also the oil separators, I have to re-read this thread and a few others on RMS leaks, but I don't think my dealer is going to advise changing them or knowing they may be the route cause of this issue.
Update: Dealer sent me video from technician, technician believes RMS is leaking, the new oil pan they installed is not leaking. I asked about oil separators and that they may be the route cause of the issue, service advisor said they are ok. Advisor is sending me a quote, they are not sure if RMS is leaking or not, theyre recommending replacing both RMS and upper oil pan??? Sounds like this is the first one they've seen, atleast for this service technician doing the work.
service advisor iladded replacing the upper main seal of the oil pan on their as there is a "small chance" it is leaking from there aswell as the RMS,
how bad is the leak? have you tried alternatives before spending 10k?
how bad is the leak? have you tried alternatives before spending 10k?
it's enough to leave oil on the underbelly pan/skid plate and leave a small oil spot the size of a few quarters on the ground. The car is still under a 60 day/3000 mile warranty from the chevy dealer i purchased it from so I am definitely going to attempt to get it fixed under their wallet. I think it's going to be a bit of a challenge trying to make them pay for it
In my case, the senior tech also checked my separators as well and found to be ok but do advise to change them out anyway, so I approved the work and hopefully this episode will not happen for at least another 4-5 yrs ... or wishful thinking. lol.
2018 E63S wagon with 52,730 miles. Purchased used last month, had an issue with an oil leak, brought to dealer, at first they found it was the drain plug leaking (probably from the chevy dealer I purchased it from and them not changing the one time use drain plug when they changed the oil on it when they got it in as a trade in). Mercedes dealer swapped a new plug in and it wasn't seating correctly, tried another new plug and it made it worse where gasket where drain plug sits in oil pan was tweaked. They replaced the oil pan free of charge. Got the car back, and was still getting a small oil spot in driveway, underside was shiny and visibly oil soaked. Brought back to dealer, they got it on the lift and video from Technician shows him believing RMS is leaking. Haven't gotten any word on a quote from service advisor yet. When I brought it in yesterday and told him about lots of people having the RMS leak he seemed complexed and didn't believe it. This might be the first one they've had in for the issue.
Looking for some advice on also the oil separators, I have to re-read this thread and a few others on RMS leaks, but I don't think my dealer is going to advise changing them or knowing they may be the route cause of this issue.
Update: Dealer sent me video from technician, technician believes RMS is leaking, the new oil pan they installed is not leaking. I asked about oil separators and that they may be the route cause of the issue, service advisor said they are ok. Advisor is sending me a quote, they are not sure if RMS is leaking or not, theyre recommending replacing both RMS and upper oil pan??? Sounds like this is the first one they've seen, atleast for this service technician doing the work.
service advisor iladded replacing the upper main seal of the oil pan on their as there is a "small chance" it is leaking from there aswell as the RMS,
Sorry to hear about the leak.
That quote is a scam and a rip-off. 80% of the total bill for labor? Scummy snakes.
That quote is a scam and a rip-off. 80% of the total bill for labor? Scummy snakes.
Get a quote from an indy.
Got a quote from an independent german repair shop, $3385 including tax just for the RMS, thats about $1000 less than Mercedes dealer. Have 2 weeks left on
60 day/3k mile warranty from chevy dealer i bought from. If the chevy dealer said they would do this repair I dont think I would trust them, would probably end up causing more problems with all the stuff you have to take apart to change the RMS. I might just bite the bullet and spend the $3385 and go with the indy shop and have it fixed thru them.
Got a quote from an independent german repair shop, $3385 including tax just for the RMS, thats about $1000 less than Mercedes dealer. Have 2 weeks left on
60 day/3k mile warranty from chevy dealer i bought from. If the chevy dealer said they would do this repair I dont think I would trust them, would probably end up causing more problems with all the stuff you have to take apart to change the RMS. I might just bite the bullet and spend the $3385 and go with the indy shop and have it fixed thru them.
my repair bill at mb dealer was $4300 + taxes. So, your indy shop is not out of whack per se.
my repair bill at mb dealer was $4300 + taxes. So, your indy shop is not out of whack per se.
did you have JUST the RMS replaced? If so how many miles were on your car when you had it done and how is the repair holding up? ( wondering if i should get a quote for oil separators aswell)
did you have JUST the RMS replaced? If so how many miles were on your car when you had it done and how is the repair holding up? ( wondering if i should get a quote for oil separators aswell)
rms + separators. I was billed for 28.5 hrs labor
parts are not that expensive, mind you.
job done back in January 2023.
at the time, i had 100,000km (62,000 miles) with 5 years of ownership. Now, 2 months later with another 3500km, no leaks as far my garage floor has shown.
Last edited by bobblehead; Mar 17, 2023 at 05:44 PM.
at the time, i had 100,000km (62,000 miles) with 5 years of ownership. Now, 2 months later with another 3500km, no leaks as far my garage floor has shown.
Update on my wagon with RMS leak after getting the $9600 quote from mercedes dealer. Brought to dealer I purchased from because it's still under their 60 day warranty, showed them the paperwork from Mercedes, told them it's leaking from the RMS. They looked at it and agreed yes it's leaking from their and the Upper Main seal of the oil pan. But before starting any labor a manager at the dealer tried to open a claim with Mercedes Corporate thru his wife who is apparently a "higher up" at a local Mercedes dealer in CT. This claim was to try and get the work all completed under a good will warranty as the car is barely outside of it's 4 year 50k mile bumper to bumper warranty (2018 with 52,600 miles). Didn't hear anything for about a day until I got a call from the service manager saying unfortunately it can't progress because the dealer I brought the car to that gave me the $9600 quote entered that I "declined" the repairs.... Service manager also questioned why that dealer never even tried to do what they did with contacting MB corporate to see if it could be covered under warranty. It's obvious that dealer didn't want to put in the effort and try to help me out at all. dealer says they have a technician that is competent enough to complete this job. So they're doing it. I'm crossing my fingers everything goes as planned and that they don't run into any issues with doing the work. It's supposed to be done middle of this week. There work is warranted for 12 months unlimited miles. It was either I have them complete the $9600 MB quote for free under the warranty or I bring it to a reputable independent shop and pay them $34000 for just the RMS. I figure I try my shot with the dealer to begin with.
Last edited by Rover338; Feb 19, 2024 at 10:07 AM.
Update on my wagon with RMS leak after getting the $9600 quote from mercedes dealer. Brought to Chevy dealer I purchased from because it's still under their 60 day warranty, showed them the paperwork from Mercedes, told them it's leaking from the RMS. They looked at it and agreed yes it's leaking from their and the Upper Main seal of the oil pan. But before starting any labor a manager at the Chevy dealer tried to open a claim with Mercedes Corporate thru his wife who is apparently a "higher up" at a local Mercedes dealer in CT. This claim was to try and get the work all completed under a good will warranty as the car is barely outside of it's 4 year 50k mile bumper to bumper warranty (2018 with 52,600 miles). Didn't hear anything for about a day until I got a call from the service manager saying unfortunately it can't progress because the dealer I brought the car to that gave me the $9600 quote entered that I "declined" the repairs.... Service manager also questioned why that dealer never even tried to do what they did with contacting MB corporate to see if it could be covered under warranty. It's obvious that dealer didn't want to put in the effort and try to help me out at all. Chevy dealer says they have a technician that is competent enough to complete this job. So they're doing it. I'm crossing my fingers everything goes as planned and that they don't run into any issues with doing the work. It's supposed to be done middle of this week. There work is warranted for 12 months unlimited miles. It was either I have them complete the $9600 MB quote for free under the warranty or I bring it to a reputable independent shop and pay them $34000 for just the RMS. I figure I try my shot with the Chevy dealer to begin with.
the repair will be warrantied - if anything catastrophic happens it's on Chevy - no worries; but sub'd for the ending to this story
Last edited by PeterUbers; Mar 25, 2023 at 03:23 PM.
I sure hope the chevy dealer is really competent enough to do the job.
I sure hope so too. I had a discussion with the service manager and he said the technician doing the work is the one they send any German cars that come in to him to work on. The technician himself said he is capable. So I'm taking their word for it and trusting them, but worst comes to worst as Peterubers said, the repair is warranted, anything catastrophic happens after they put it back together it's on them. I asked them to take photos as the work progresses so I'll try and upload some as it goes
Last edited by Rover338; Mar 26, 2023 at 10:43 AM.
I sure hope so too. I had a discussion with the service manager and he said the technician doing the work is the one they send any German cars that come in to him to work on. The technician himself said he is capable. So I'm taking their word for it and trusting them, but worst comes to worst as Peterubers said, the repair is warranted, anything catastrophic happens after they put it back together it's on them. I asked them to take photos as the work progresses so I'll try and upload some as it goes
Good luck with repair. Did you decide to have the vapor separators replaced "while they're in there"?
Good luck with repair. Did you decide to have the vapor separators replaced "while they're in there"?
good point - he should follow the benz recommendations on this repair if he's going to be 28 hours of work into this ... may as well replace those $45 plastic parts that caused this issue; I think it'll be just fine
Good luck with repair. Did you decide to have the vapor separators replaced "while they're in there"?
When it was at the mercedes dealer I told them to look at the oil separators and that they could be the cause of the RMS failure. They told me they were OK. The Chevy dealer is only doing what is on the quote from Mercedes which doesn't include the separators. Time will tell if the separators are bad and the RMS starts leaking again after the repair.
good point - he should follow the benz recommendations on this repair if he's going to be 28 hours of work into this ... may as well replace those $45 plastic parts that caused this issue; I think it'll be just fine
Can you link to where changing the separators is part of the Mercedes' recommendations when doing this repair. I know in either this thread or another one about RMS leak someone stated their Technician had to get further assistance from Mercedes in Germany and they advised replacing the separators. I told the advisor at my Mercedes dealer that and he shrugged it off and didnt believe that the separators would cause the RMS to leak, he also didn't believe the RMS was leaking in the first place.. then they diagnose it as RMS is leaking and he told me my speculation was correct! If i can show the dealer a legit protocol from Mercedes that the separators need replacing or else the RMS is going to fail again I believe they would change them. Otherwise I don't think they're going to replace them by me just repeating others' experiences posted on a enthusiast web forum
Last edited by Rover338; Feb 19, 2024 at 10:13 AM.
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