E-Class (W212) 2010 - 2016: E 350, E 550
Sponsored by:
Sponsored by: CARiD

E350 CGI Valve stem seal change

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Oct 27, 2020 | 04:41 PM
  #1  
bhpplease's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2019
Posts: 54
Likes: 9
From: London, UK
2010 E350 CGI S212 // 2004 SL500 R230
E350 CGI Valve stem seal change

Hey guys,

I have narrowed down my oil burning issue to worn valve stems seals. Engine is the M272.983 (CGI) Variant and 200k miles.

Wondering if I can do the valve stem seal job in situ in the car by taking off the valve covers and using "the roper method" to fill the cylinder to prevent dropping the valve?

Any body got any ideas or pointers?

The alternate options are just to throw some additive at it and let it run until it burns out the cats, or take out the engine and rebuild the head and probably pistons/cylinders too (because it's out).

How long does it take to burn out the cats? I am doing about 5k miles per year at the moment.
Reply
Old Oct 27, 2020 | 07:21 PM
  #2  
nota_amg's Avatar
Super Member
 
Joined: Nov 2011
Posts: 973
Likes: 376
From: Austin, TX
2013 SL550 BiTurbo
wait...burn out the cats??? huh? why would you think that would be something that would help your valve seals? It would reduce backpressure, but the valve seals will still leak. also, "burning" the cats out would take an enormous amount of heat and wold not be good for other components on the car. Seems like a really bad idea...
Reply
Old Oct 27, 2020 | 08:56 PM
  #3  
chassis's Avatar
Out Of Control!!
MBWorld Ambassador

5 Year Member
Liked
Loved
 
Joined: Sep 2018
Posts: 14,663
Likes: 4,567
From: unbegrenzt
2017 GLE350 4MATIC
Remove the cylinder heads and rebuild them, have them rebuilt, or buy replacement heads.
Reply
Old Oct 28, 2020 | 06:13 AM
  #4  
bhpplease's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2019
Posts: 54
Likes: 9
From: London, UK
2010 E350 CGI S212 // 2004 SL500 R230
Originally Posted by nota_amg
wait...burn out the cats??? huh? why would you think that would be something that would help your valve seals? It would reduce backpressure, but the valve seals will still leak. also, "burning" the cats out would take an enormous amount of heat and wold not be good for other components on the car. Seems like a really bad idea...
Oh sorry for the confusion.

I was coming at this from a solution of last resort. Meaning that I don't pour loads of money into the car and just drive it until I can no longer drive it. By that I mean drive it until the consumed oil ends up burning out the cat and it fails the emissions test. Here in the EU we have a test each year. It passed without issue in September so there is another year at least.

I bought the car two years ago with 190k miles, i've done 10k on it (5k year) at a cost of £5k against usual market price of £12-14k. So economics comes into play here and could suggest that if I get another year or two out of it, could work out as not totally expensive driving.

Bit of a coin toss really. A pity though as I love the car and had planned on keeping it 10 years or so as a daily whip.
Reply
Old Oct 29, 2020 | 09:20 PM
  #5  
911st's Avatar
Newbie
 
Joined: Apr 2015
Posts: 14
Likes: 2
00ML 320, 11 E350, 12 ML350
My guess: If you do not want to have the heads rebuilt, do a leak down test to check to see if it is worth it. Most cars, and my old 190E, the stem seals are replaceable without removing the heads. But there is a lot of plumbing and electrical on the top of that motor that will have to come off. Not to mention the cams. Taking the heads off is not much more work (exaust and coolant). Me, I would rather cut my losses, sell with full disclosure and start over. Still, there is somthing to be said for doing no more than you have to and try for another 100k miles.
Reply
Old Nov 1, 2020 | 07:02 AM
  #6  
nota_amg's Avatar
Super Member
 
Joined: Nov 2011
Posts: 973
Likes: 376
From: Austin, TX
2013 SL550 BiTurbo
Originally Posted by bhpplease
Oh sorry for the confusion.

I was coming at this from a solution of last resort. Meaning that I don't pour loads of money into the car and just drive it until I can no longer drive it. By that I mean drive it until the consumed oil ends up burning out the cat and it fails the emissions test.
if cost of ownership is your main concern, this may be the best option, honestly. Or, try to find a used catalyst section of exhaust and just swap that out when/if the cats die?
Reply
Old Nov 1, 2020 | 11:51 AM
  #7  
Trevor Hadley's Avatar
Member
 
Joined: May 2017
Posts: 148
Likes: 18
mercedes w123 260e
Use the thread from an old spark plug ,,weld this to a metal tube. Now you can fit a rubber hose on to the end with a good clip ,,it will need to be airtight.This then screws in to the plug hole , next thing is to pressurize the tube you made so the pressure holds up the valve your working on .No compresor dont worry remove an oldb tyre valve ,fit this to the other side of the rubber hose with another good strong clip ..it too must be airtight .Do this and check it after its been pressurized with a tyre pressur gauge you can do this with a tyre gauge to see if it is loosing pressure before you start the job. Good luck this can be done on conventional engines might be possible on yours ..
Reply
Old Nov 1, 2020 | 08:14 PM
  #8  
bhpplease's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2019
Posts: 54
Likes: 9
From: London, UK
2010 E350 CGI S212 // 2004 SL500 R230
Originally Posted by 911st
My guess: If you do not want to have the heads rebuilt, do a leak down test to check to see if it is worth it. Most cars, and my old 190E, the stem seals are replaceable without removing the heads. But there is a lot of plumbing and electrical on the top of that motor that will have to come off. Not to mention the cams. Taking the heads off is not much more work (exaust and coolant). Me, I would rather cut my losses, sell with full disclosure and start over. Still, there is somthing to be said for doing no more than you have to and try for another 100k miles.
I'm not really interested in selling. I don't think i'd find a buyer that easy for a 200k miler that is burning more than it's fair share of oil.

I have considered compression + leak down tests.

Originally Posted by nota_amg
if cost of ownership is your main concern, this may be the best option, honestly. Or, try to find a used catalyst section of exhaust and just swap that out when/if the cats die?
Cost of ownership isn't really my main concern, but I don't want to start throwing thousands at this problem. I kind of figured that buying the car at well below the market price of a similar 100k miler, I was getting a good deal etc. (£5k versus £12/14k) I don't want to negate other wise it kind of makes this a fools errand, in my opinion.

I like the sound of swapping out the cat sections. Overall I really love this car. The colours, spec and that V6 really does it for me. In January I will have it 2 years and I have often said I will keep it for many years. I suppose with that attitude I should be doing the engine job. But on the other hand doing nothing and seeing how long I get might be the most economical.. There is something sorry about knowingly driving a car to it's death though.. especially a beauty of a MB V6 and the notion that 200k is "small mileage".

Imagine I rebuilt the engine. Whole kit and caboodle (Block + Head) inc valve train, timing pistons etc.. Is it fair to say the engine is like new and good for another 200k miles?

Originally Posted by Trevor Hadley
Use the thread from an old spark plug ,,weld this to a metal tube. Now you can fit a rubber hose on to the end with a good clip ,,it will need to be airtight. This then screws in to the plug hole , next thing is to pressurize the tube you made so the pressure holds up the valve your working on .No compresor dont worry remove an oldb tyre valve ,fit this to the other side of the rubber hose with another good strong clip ..it too must be airtight .Do this and check it after its been pressurized with a tyre pressur gauge you can do this with a tyre gauge to see if it is loosing pressure before you start the job. Good luck this can be done on conventional engines might be possible on yours ..
Very good idea.. the spare tire sure does come in handy.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Sep 20, 2021 | 09:11 AM
  #9  
Frank W's Avatar
Newbie
 
Joined: Sep 2021
Posts: 9
Likes: 3
From: El Segundo
2013 C63
Wow congrats! Super clean low miles, not too many left out there.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 11:34 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE