C-Class (W204) 2008 - 2014: C180K, C200K, C230, C280, C300, C350, C200CDI, C220CDI, C320CDI

250 cgi secondary air pump pressure oil leak?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Sep 6, 2019 | 06:36 PM
  #1  
Jethro71's Avatar
Thread Starter
Newbie
 
Joined: Dec 2018
Posts: 8
Likes: 0
s204 250cgi 2010
250 cgi secondary air pump pressure oil leak?

Hi. I have the 271.860 Engine and i had some problem with the secondary airpump that got stuck and burned fuses, but this was not the only problem apparently that needed fixing. I found some oil leaks in what i thought first was the turbo return line but what i can see now is connected with the secondary air system. I took some pictures to illustrate. Can someone please help explain how it can leak oil from the air shutoff valve like that? Im going to take the valve appart and see if its somewhat broken and clean it meanwhile.




Reply
Old Sep 7, 2019 | 09:24 AM
  #2  
MB Marko's Avatar
MBWorld Fanatic!
 
Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
That valve looks like it clogged to hell with carbon build up. I'm not sure about the oil but I've had issues with my system. I have threads posted with pictures on what I did to fix the issues and the car hasn't had them since.
Reply
Old Sep 7, 2019 | 04:39 PM
  #3  
Jethro71's Avatar
Thread Starter
Newbie
 
Joined: Dec 2018
Posts: 8
Likes: 0
s204 250cgi 2010
I took a look at your post and it looks identical, alot of carbon and the same rubber seal almost falling of when cleaning the housing. Im curious do you know the serial number for a new rubberseal or do you have to ask the MBdealer? How do you replace it do you have to force the valve open, and how exactly did you glue it?
Reply
Old Sep 7, 2019 | 08:17 PM
  #4  
MB Marko's Avatar
MBWorld Fanatic!
 
Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
The seal in mine was like a paper seal that crumbled. I took gasket maker and cut a seal out myself and used gasket glue to hold it in place. Those valves aren't meant to be rebuilt, that's what the dealer told me. I tested the valve with and air hose once I was done .
Reply
Old Sep 8, 2019 | 04:08 AM
  #5  
Jethro71's Avatar
Thread Starter
Newbie
 
Joined: Dec 2018
Posts: 8
Likes: 0
s204 250cgi 2010
Ok thanks, i thought the seal for that was available. Any thought on what gasket maker? One alternitive could be to use a small sheet of the same material you cut also cut a seal out? The valve open and closes did you open it some way?
Reply
Old Sep 8, 2019 | 09:43 AM
  #6  
MB Marko's Avatar
MBWorld Fanatic!
 
Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
Amazon Amazon
use this and some gasket glue.

I can't remember if you have to blow air into the port or suck it to keep it open. Once open you need to jam it up with something until you have the gasket made. I thought I posted a step by step in one of the threads
Attached Thumbnails 250 cgi secondary air pump pressure oil leak?-photo456.jpg  
Reply
Old Sep 10, 2019 | 05:09 AM
  #7  
Jethro71's Avatar
Thread Starter
Newbie
 
Joined: Dec 2018
Posts: 8
Likes: 0
s204 250cgi 2010
Thanks for the inputs, but now i seems to have gotten a bigger problem. I found oil in one of the tubing to the air intake and between turbo and intercooler. I called the mercedes dealer but of course she want me to just leave the car with them. They dont want to anser any questions, i just want to know, and im hoping for a problem with the crankase ventilation system but dont know how freqent this kind of problem is? Worst case would be turbo or cylinder oil leak. Im going to try and get the oil separator open in the engine valve cover, but dont know exactly jet how jo open it on my car. I have to get back.

Reply
Old Sep 10, 2019 | 07:55 AM
  #8  
MB Marko's Avatar
MBWorld Fanatic!
 
Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
I only noticed condensation, sorry I can't be of more help. All I can say is if you know a independent mechanic they are more willing to help DIY guys. The dealer guys usually don't say much unless you have a relationship with them. You can order work manuals online it may help if you just buy the set for your car. There not expensive and night let you know how the systems work together.

The system is a pain in the *** if your buying parts use rockauto or FCP euro they have life time warranty rock auto is cheaper but less warranty. I bought a new pump but actually opened the old one and it was full of carbon build up I cleaned it all up now I have a back up if it happens again but it's been a while so I don't think it will happen again lol fingers crossed.
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

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 10:37 AM.

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