C220 Cdi 2001

[John Kerr]

If the Cat was starting to go .Would this give a lack of power when engine gets to 2000revs.Anyone had a Cat go and what were the symptoms.

 

[Blobcat]

More likely the MAS sensor

 

[HJHPH]

Hi, I have recently had the pre cat fail on my wifes 220cdi (26K miles!) which then blocks the exhaust solid causing loss of power, car drives like the handbrake is on takes ages to get to 60 and slows up on hills. They have replaced both at great expense (some paid for by MB).
All sorted now but it is usually the pre cat that does the damage so I am told.
Paul.

 

[John Kerr]

Many thanks for you replys.The MAS sensor is this different to Mass Air Flow if so where would I find it.Is there anyway of checking sensors with a multimeter.

 

[johngun1]

MAS Location

Hi John Kerr,

I just had the same problem on my C220 CDI 2001and thanks to advice from one of these helpful guys here I've got a replacement MAS from the Bosch dealer £55.00 + VAT, fitted it and its like new again. Bosch part number was 7-22684-07.

You can get them cheaper on EBay but I felt happier not risking my card (no offence to EBay).

You'll find the MAS at the front left corner of the plastic cover on the top of the engine. It looks like an oval shaped plastic plate with a large electrical connector on it. You'll need to remove the top plastic cover from the engine (6 Torx screws).

Once this is out of the way, press the two little clips on either side of the electrical connector and pull it off. Now using a smaller Torx driver unscrew the two screws that hold the MAS into the induction pipe. The MAS fits through an "O" Ring so you need to twist it gently as you pull it out.

Fitting the new one is simply a case of reversing this process. You can't get the position wrong because the screws are off-set, so it only goes one way. Took me 20 mins taking my time, from popping the bonnet to taking it for a test drive.

If you look on EBay you'll see photos of MAS units which appear fitted to pieces of pipe. The one on the C220 CDI 2001 in supplied as just the sensor itself without the pipe because it fits into what is the air filter housing.

Tools required? Just a set of Torx drives, my cheap set cost me a fiver. I don't know what a dealership would quote but my local one charges £85.00 per hour so I'd guess something like £200.00 for the job. That's of course if he thinks he can't get away with more!!

Cheers

john

 

[johngun1]

MAS Location

Forgot one point.

An easier way to check the MAS:

With the faulty MAS fitted the engine wouldn't rev above 3000 RPM standing. It was acting like a rev limiter.

Cheers

John