Engine management on a w203 :(

[jameshaydon]

wondered if anyone could give me with any advice on my engine management light being on. I have had a diognostics done on the car, and the fault that is showing up reads "mixture to lean" the garage i took it to simple just "cleared" the fault, but has now appeared once again, does anyone know what i can do myself to help clear this, and also is it safe to be driving still ?

many thanks

James

 

[Justin1600]

What engine does it have mate ?

111,112 or 271 ?

 

[jameshaydon]

its a c200, 1.8 litre...

many thanks justin

 

[R2D2]

James we need to know what engine it is. What year is your car if you don't know what engine type you have. If it is a M271 type engine this fault is either due to a failing air mas sensor or a perished rubber hose which is under the air box and is a so and so to get to. When mine failed it was the rubber hose which is a £8 part and not the air sensor which is '00s part (although if you have a M271 engine i happen to have a new MAS for sale!)

 

[Justin1600]

Need to know the year of C Class or more importantly the engine code mate.
As R2D2 said, if it is a 271 engine which is normally 2003 onwards then it could be a split breather pipe under the airbox.
If it is a early C Class with a 111 engine it could even be oil in the engine wiring harness which can be expensive to put right

 

[jameshaydon]

its a 54 plate guys ..... not sure where i could find the engine code for yas, sorry about this....

James

 

[R2D2]

Ha found a photo of a M271. If it looks like this then it is a M271 engine in which case it is the MAS or the hose under the air box. Where in the country are you?

edit ignore the red box!

 

[jameshaydon]

thats the one R2D2 that i can make off, unless the other 2 engine sizes are only minimal difference that i cant make out? i am in grays in essex... many thanks for your help

James

 

[R2D2]

thats the one R2D2 that i can make off, unless the other 2 engine sizes are only minimal difference that i cant make out? i am in grays in essex... many thanks for your help

James

Several thoughts:

The place where our get-to-gether is being held helped me fix the same problem on my car. The link at the bottom contains details both for the GTG and MB Medway.

2nd thought is I still have a new boxed MAS for sale if you need one or want to change it at the same time as the hose

http://www.mbclub.co.uk/forums/classifieds-general-sale/104039-air-mass-sensor.html

 

[Justin1600]

Will be the breather hose split mate, not easy to change. But i can do them in 15 mins now
Then sometimes it is best to get the mixture/fuel adaptation reset on Star Diagnosis aswell as the fault codes cleared

 

[R2D2]

Will be the breather hose split mate, not easy to change. But i can do them in 15 mins now
Then sometimes it is best to get the mixture/fuel adaptation reset on Star Diagnosis aswell as the fault codes cleared

Are you an MB garage cos 15mins is quick especially with the horrible breather pipe at the back.

 

[Justin1600]

Are you an MB garage cos 15mins is quick especially with the horrible breather pipe at the back.

They are not nice to change, but i have changed 30 or so for people. :bannana:

 

[jameshaydon]

Where are abouts are you Justin? And am I safe to be driving if it is the breather hose that has split?

James

 

[jameshaydon]

Many thanks r2d2, would it be more sensible to replace the hose first... And if this has not sorted the problem, then to change the sensor? Also how much would you be selling for?

Many thanks

 

[R2D2]

The breather hose is a different hose that needs disconnected in order to get the air box off and it is a so and so. the hose that splits is under the airbox and once you can get access to it, it isn't too bad to change . the difficult bit is that the ECU and all the plugs etc , the whole MAS and airbox need removed in order to get to the stupid rubber hose. As long as it is the £8 hose then you should be ok to drive around on it. If it is the MAS and it gets to a critical state the car will either drop into limphome mode or will become almost undriveable with max revs of about 2000. It is a job to get done sooner rather than later. If you want to do the MAS at the same time as the hose (while it is all apart) then you can have mine for £50 a saving of about £240!

 

[Justin1600]

Where are abouts are you Justin? And am I safe to be driving if it is the breather hose that has split?

James

You can drive it James, the engine management will try and adapt to the air leak. Will just put the EML light on and probably tick over lumpy.

Where abouts are you located mate ?

 

[jameshaydon]

You can drive it James, the engine management will try and adapt to the air leak. Will just put the EML light on and probably tick over lumpy.

Where abouts are you located mate ?

I am in Grays in essex, have just purchased breather hose from my local mercedes garage at £6.50 next step is to get this fitted :/

 

[jameshaydon]

The breather hose is a different hose that needs disconnected in order to get the air box off and it is a so and so. the hose that splits is under the airbox and once you can get access to it, it isn't too bad to change . the difficult bit is that the ECU and all the plugs etc , the whole MAS and airbox need removed in order to get to the stupid rubber hose. As long as it is the £8 hose then you should be ok to drive around on it. If it is the MAS and it gets to a critical state the car will either drop into limphome mode or will become almost undriveable with max revs of about 2000. It is a job to get done sooner rather than later. If you want to do the MAS at the same time as the hose (while it is all apart) then you can have mine for £50 a saving of about £240!

My EML had been on and off intermittent for around 6 weeks now, if it was the MAS, would I not have experienced the problems you have said could potentially happen already? I have just bought the hose from mercedes, looking around now to be fitted, if the problem isn't sorted within the next few days, with the hose changed, I will take it


Many thanks r2

 

[jameshaydon]

Does Anyone know, if once the hose has been replaced, the EML light will go on it's own? Or will I have to defanatly pay for another diagnostics to clear it?

Many thanks

 

[jameshaydon]

You can drive it James, the engine management will try and adapt to the air leak. Will just put the EML light on and probably tick over lumpy.

Where abouts are you located mate ?

mercedes have quoted me £220 to fit the hose ?! (if it is the hose running from the super charge into the air box) as the fitter said......

surley not ?!

James