Hello Guys,

I must admit my C220 always baffles me with a unique problem, probably nowhere found to be on the web.

So today my car was lifted on the ramp for tracking and I nearly fainted when I saw a film of oil on the plastic shield under the engine bay. I thought turbo is out or something catastrophic is about to happen!

So when I came back home I remove the sheild and found that some where from the Intake manifold the oil is seeping. I need to investigate more obviously! but have few questions from the community.

Is OM646.811 plastic inlet manifold known to leak or crack ?
Gasket can be suspect ? (attached schematic - EPC)
Has anyone experienced it ?
Since the turbo pipe is connected to this unit - Can turbo pressure cause this ?

What do I need to worry about.

The car has no power loss nor any strange symptoms that I know off. Is high 139K miles though, serviced by MB as per recommended schedules.
There is no mega oil loss between services - I do loose just a little less than litre after 10K miles which I think is normal. I do approximately 500 miles minimum a week (motorway miles only)

Do you think Item 20 / 25 can be suspects (EPC Attached ) ?

 

Hello AA,

The only slight leak I have experienced is where the sump breather pipe enters the bottom of the inlet air ducting before the air cleaner .This is located at the front of the engine on our drivers side just above the return radiator hose..

I would expect as your engine ages & wears more oil carry over would occur to this area with possible leaks at joints in this ducting.

You may need to clean your area up then do an inspection after a run with a strong torch. Hopefully it is just a hose or duct leak.

Keep us informed.

 

That's a pretty small amount of oil. At this stage I'd just clean it and monitor it.
When/if it becomes larger then I'd replace the intake manifold seals that you've highlighted as well as the intake manifold. When it's a big leak there is usually a loss of power/air leak noises under boost and/or oil completely covering that side of the block.

Nothing to worry about at the moment.

 

Thanks Ausmbtech, a couple of questions why would it be necessary to change the intake manifold itself ? .Does it become damaged, warped ?.

Also, is this condensed oil vapour from the sump?

John.

 

Thanks Guys, I am not gone but trying not to waste money by fixing something that does not need fixing Still trying to identify leaks etc etc. The turbo seals are healthy. The oil in the charging unit is from the breather.

So since my last post I have identified few things bullet pointing them below.

. I cleaned all parts that had oil residue to the level everything looked almost new! so I can observe where is the leak is.
The plastic shield under intercooler had a thick smear of oil ( about 2-3 table spoons) most towards the intake rubber hose. I thought the hose clamp was loose or the pipe cracked but upon close investigation found nothing. All seems ok including O ring. Inside the intercooler I found film of oil and not puddles which is a good sign. So I cleaned everything to the best as I can and refitted hose ensuring its tight.

. Drove around 200 miles and I could again see a film of oil on the bottom of intercooler plastic. I think intercooler may have a minor leak. But i when I rev the engine. I can see the turbo actuator doing its stuff. The car hold the boost, the pipes swell up as you would expect but,..

. My car has developed a crazy fault recently (no codes on star) and I am pretty certain it is boost related. Bear with me as I try to explain it. The car has not yet gone into any sort of limp mode etc etc.

. When I am at high speed say 60mph and attempts to over take another vehicle, the gear will shift down (as expected) rev goes up, I can feel the turbo kicking in BUT it starts to do boost creep. The car would drop boost and gain in a consistent manner whilst building up speed if I dont let go of gas - it will get to the desire speed I need. This only happens and high speed and at lower speed everything is fine.

What could cause something like this ? MAF, boost pressure sensor, actuator, flaps in inlet manifold( if OM646.811 has them), fuel related. I am trying to solve this mystery and it seems like a difficult one.

The intercooler which I suspect is leaking does not make any wooshing noise etc etc. I am puzzled! Open to suggestions.

 

I 'think' I am happy today since I found the issue. The boost creep could be because of possible boost loss from the intercooler. See attached photo and video link. It is very very minor though. Can this cause boost issues. I used washing liquid so I can see bubbles. Even at idle it is leaking. Can someone shed some light i.e. this level of leak is enough to cause boost issues. I am ordering a new inter cooler today anyway! but would like to welcome your thoughts.

Attached:
Photo of the leak and oil creeping on the bottom of intercooler's right hand side.
Video: https://vimeo.com/167917720





https://vimeo.com/167917720

 

I cannot see that that volume of air could cause your problem but it may be much larger when the turbo is at full boost pressure. It may cause an inbalance in the measured air/fuel ?

 

Thanks Carsy. I am hoping this will fix one oil leak and the issue I am having. May be a turbo expert can educate us a bit more on this. I do agree it is a minor leak but at full boost what happens; I have no idea! Regardless, the intercooler needs replacing. So lets see how it goes.

 

Hi Guys,

Update,..and few questions please. (Photos attached where I could)

* New Intercooler fitted took me approximately 2 hours to swap old with new; includes the bumper refitting. intercooler swap is very easy I would say.

* The original Intercooler was a genuine unit Part Number A2045000300..

* On close observation I found the minor puncture was only at front of intercooler but off course that warranted a replacement.

* The Unit I replaced with was original Merc part - brand new including VAT was £374 ( which is the total cost - Yet!)

* All of my pipe work seemed ok. I degreased the section of the engine bay wherever there was oil mist creep. It literately looks brand new. Engine bay is oil free.

* There was absolutely no oil in the inter cooler. The only bit that came out after I left the intercooler facedown for an hour was a few centimeters of oil film (photo attached). This does mean the turbo seals are intact sofar!


Overall I was happy with the job that I nailed one issue down (oil leak/mist) and was expecting the car to perform normal and was hopping the boost creep or the power loss / regain on high speeds (AKA slow surging - AKA I don't know what to call it or way to explain it ) will be resolved but it didn't

However from stand still to redline in 1-2 second gear. I can certainly see boost improvement but as soon as speed starts to increase the surging start to develop from 3000 Plus rpm. Car does not give up and continues to build speed but the feeling is very annoying!

In fact I can clearly say the surging / boost creep is now more pronounced after intercooler replacement!.

On further close observation I can see oil mist building up again (after I cleaned up last time) under the inlet manifold section plastic pipe work that leads to intercooler hoses. So not sure where the problem is.

My car has not gone into limp mode yet. I am still confused where the issue it.

The mpg is fine and as expected.

where can be this fault. Has anybody ever experienced anything like that!

 

Boost surging is usually a boost control issue, check the lines going to the wastegate and the associated solenoids and valves. If something isn't working as designed it can cause boost fluctuations.

 

Thanks ItalianJoe1 - Is the wastegate actuator based ? on w204 with om646.811

 

I'm not familiar with the system on that particular engine but in general, any modern automotive diesel engine will have electronic wastegate control, so there will be a solenoid, pressure reservoir and check valves, all connected by rubber hoses. All it takes is one crack or leak to lead to a surge condition.

 

Thanks. Car will be connected to star this saturday. I'll keep you guys posted. Not giving up!

 

Nor should you, thanks for sharing .John.

 

Hello, I've not vanished in thin air but the quest for actual problem is still on. I also do not want to spend and replace parts which do not changing.

Star diagnostic does not reveal anything.

To rule out that it is not the pump and or injector(s) I've booked my car with authorised delphi diesel specialist coming Thursday in Essex.

So I will keep you posted.

On a side note - I don't know the rules - am I allowed to cross link similar problem on another forum where the guy suffered same problem and it came down to bad HP pump ?

my car is on 163K miles - I still love it!

 

The more info the better from all sources as far as I am concerned. JC

 

Hi Atom-ant! I've got exactly the same thing and I'm curios what did you do?
What news?
You can write directly to igoriakovenko@bigpond.com
I'm in Australia - Melbourne
Regards. Igor.

 

Sorry been away. The fuel injection tests were waste of time any money and did not yield any benefit.
In the end it came out to be Oxygen sensor fitted in the turbo manifold. Which resolved the issue.

 

Putting an end to this thread. I sold my loved C220 CDI last week with issues resolved. I persevered a lot and it seemed like that the car would eventually become a project. As I feared due the millage (not age ) some more things might show up in future.

I now own a Lexus.
Thanks to all who helped me from May 2015 - to Dec 2016. Happy New Year and enjoy / look after your Mercs.

 

Thanks for the update ,Merry Christmas to you. Good luck with the Lexus. John

 

Aww sad to hear mate I take it your not going to be on this forum anymore then