falcoFBS

Hello everybody.

First of all I apologize for my English skill, will try the best as I can.

My 1st post here -unfortunately for bad reason and will much appreciate if someone can give me some advise.

So, my car is C200K Petrol, Manual, 2001, 70000 miles.

Here is the problem.
Two months ago the engine light on the display come ON. The dealer set Air Mass Sensor is faulty.
New part from Mercedes is about £300, so I bought from e-bay brand new coming from Chine for £40.
Replaced it (everything was ok) and after 10 days the light again ON.
The dealer check again and found that the magnet (in front of engine) and plug was in oil. So new magnet and good cleaning sort the problem for 2 days (about 100 miles), and again the light.
After that I left the car for 3 days to dealer to check, try and replace what ever they think.
So they replaced two sensors (presure sensors) which I don't know. They just set there are exactly the same parts number but in different place (one is close to the Air Mass sensor).
They test the car for 200 miles (3 days) without any problems.
Yesterday I collected the car and unfortunately today (after 30 miles) -again the light.

Tomorrow again I will visit the dealer, but I'm worry how far this problem can go.
Is the way to solve this problem is to replace everything possible?

Once again I will much appreciate for any advises. Thank you!

dmatre

It sounds like the cam sensors were leaking oil, and this oil is now inside your engine wiring harness.

The sure fix is to replace the engine wiring harness (and to install the new pigtail for the cam sensor wiring - to prevent this problem in the future).

Some on this board have had success cleaning the wiring harness. You can search for the threads. Search 'Leaking Cam Sensor" in the W203 forum and you will find lots of information.

Glyn M Ruck

Make sure that the cam sensors have been changed - Make sure that pigtails have been fitted - If so take dmatre's good advice & replace or clean thoroughly engine wiring harness - ensure that no oil has run down the harness & contaminated the O2 sensors.

falcoFBS

Thanks a lot for the quick response and advise.
You are just Great!
I have appointment tomorrow with the dealer, so will see tomorrow what will happen.

Also the magnet is new (is only one) and I already cleaned all the cable plugs with BrakeCleaner (thats what the dealer recomended) and really there was a lot of oil inside the plugs. Even that the light still there.

Any way will post back to let you know how everything is going.
Thanks again for your help (also with the photos).

dmatre

If you had oil in the plugs, then most likely the oil has worked its way down to the O2 sensors, the MAF, and the ECUs.

The oil changes the resistance of the sensor connections, giving 'false' data to the ECUs.

If you have a chance to clean the entire wiring harness, this will most likely resolve the matter. Or, you can replace the entire harness (about $1200 US including labor).

Or, you can continue replacing components (which really aren't bad - just oil-fouled electrical connectors), and seeing the re-occurring CheckEngine light as the oil that is still in your harness works its way down to the next component connected to the harness.

Good luck!!!

Glyn M Ruck

Yes, this sounds like a bad case & best would be a new engine harness or it's going to continue giving trouble.

falcoFBS

I've been already twice to the dealer in the last two weeks.
They've replaced (not sure for the name) the parts on the top of the sparking plugs and topped up the petrol with some cleaner.
Unfortunately again LIGHT.

I checked all the plugs in MAS sensor, CAM (magnet) sensor and O2 sensor - everything looks OK without any oil.
Just don't know what to do now.

falcoFBS

GOOD NEWS (fingers cross)

Now about two months latter and 1500 miles - everything looks to be OK.
So, what was the problem - dirty throttle body.
After good cleaning and even I put back the old original Air Mass - the Light has gone.
Just hope no problems for many years.
Thanks to everyone and wish to all of you safe journey.

tturcica

my c200k 2004 model engine sign on
changed org. 02 flowmeter end lambda sensors and plugs and oil and etc
but no turn off
i will change the throttle body but i dont know its aparat where is the engine
where is the throttle body on the engine can you see to me

Glyn M Ruck

Get the vehicle onto an OBDII scanner and tell us what codes show up.