MAF problem ?

JimHatton

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Hi Guys

I've had a good lurk for the past year or more and have found this forum most useful. I have a C180K Classic SE - 03 plate which I think makes it a W203. A few weeks ago the engine check warning light came on. My local garage, bless them, have a plug-in ECU computer thing which gave a list of fault codes stored in the ECU. The main one seemed to indicate that the MAF was the problem. There were several other codes relating to correcting misfire on cylinder 4 I think.

Before the engine check light came on i had noticed that tickover was a bit lumpy. I had also noticed that the car might be lacking power a little. The garage re-set all the fault codes and suggested a wait and see approach. Didn't have to wait long because as I was driving off their yard the engine check light came on again. They plugged in the widget and the code was once again pointing to the MAF. They reset the code and said if it came on again to call back in and get the car booked in.

The other day the engine stalled just as I was turning a corner. This was actually quite scary as all of a sudden there was no power steering and the brakes didn't work properly. When I restarted the engine the engine check lamp was on again.

Right now the check engine lamp comes and goes but there is still rough tick-over. However, and here's the point of this note, my fuel economy is not lower than normal. If anything I'm getting a better mileage than I would normally get. Today I had to drive 70 miles from the airport to home and the engine check light came on when I started the car. The trip computer seemed to be telling me that I had done an average of 41 mpg for this trip, which is rather more than I would expect.

It does look like I'll have to bite the bullet and get the MAF replaced, but before I splash out 400 for the garage to fix it, is there anything else it could be ? I've just searched the house for the ECU printout so I can tell you the actual code but it seems that my wife has put it somewhere safe :)

Any advice appreciated.

Thanks

Jim
 

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Just go to any Bosch agent and buy one and fit it, from Bosch they are ½ the MB price
 

jibcl500

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As Malcolm said, find your local Bosch agent give em a ring quote the Bosch part number off the MAF, go collect and pay for it then fit it, dont be tempted to buy one off ebay for £50 because they dont work very well.

jib
 
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JimHatton

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Well, here's the interesting thing. My local garage quoted me 210+VAT for bosch part whereas the MB garage I normally use quoted me 270+VAT for genuine MB part which has a 2 year warranty. Total price from MB garage to replace MAF was 380 and price from local garage with bosch part was 340. Rock - me - hard place. !
 

Richard Moakes

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Jim, unless there is something special about the W203 then its normally a very simple job to replace a MAF. Do you have any car savvy friends who could fit it for you if you pick one up from a Bosch dealer?
 
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JimHatton

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Hi all

Unless it's an especially hard job I reckon I could do it myself, I suppose I'm a little concerned about two things in particular - first, does the MAF need replacing or whether there could be a different problem causing the faults and secondly the fact that the MB part vs the Bosch part didn't seem to be that much different in price. I asked the MB garage if they were using a Bosch part or the genuine MB part and they said that they would only use MB parts.

Jim
 

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Hi all

Unless it's an especially hard job I reckon I could do it myself, I suppose I'm a little concerned about two things in particular - first, does the MAF need replacing or whether there could be a different problem causing the faults and secondly the fact that the MB part vs the Bosch part didn't seem to be that much different in price. I asked the MB garage if they were using a Bosch part or the genuine MB part and they said that they would only use MB parts.

Jim

The MB MAF is a Bosch one, MB do not make MAFs it has a Bosch part number inside
 
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JimHatton

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Malcolm,

I knew that asking this forum was the right thing to do. Anyway, my local garage (freelance) told me that they got a price for the Bosch MAF and it was something like 210+V. Is it likely that this is the right price ? Looks like the wallet is in for a bashing :-(
 
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JimHatton

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OK - so let's assume that I get a new MAF from Bosch (definitely not e-bay) and work out how to change it. Is there anything else I should have to do, like reset fault codes in ECU or whatever ? I mean, is the job limited pretty much to taking old MAF out and putting new one in it's place ?

Jim
 

jibcl500

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No a new MAF and the ECU's are ok to accept the new MAF and things will return to normal, there maybe a fault logged on the ECU but it wont affect the cars performance.

Easy to fit once you found the old one work out how it comes out and reverse the removal.

jib
 

star

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are you sure its the MAF, i had an injector go recently on the very same model giving the symptoms you have??
 
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JimHatton

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Hi Star

The fault codes showed a number of issues, there were a few corrections for misfire on cylinder 4 but the top code was the MAF. After the codes have been reset, the one that comes back again when the check engine light comes on is the MAF code. Would an injector problem give the same code as a MAF problem ?

J
 

star

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I doubt it, you could read the injector duration to double check, but if you let the garage do the job, and if they diagnosed incorrect, they should refit your old parts and credit you. its alot of money to guess.
 

bigasotonuk

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Hi,
Bought the one on my C230K off of E-bay, I,ve had no problem with it.
 

rmt6668

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Can you actually clean the delicate sensor (the tip) buy spraying a disolving solution? What about that oil on that small window?

I read somewhere that sensor had already a protective membrane/coating. If we use some penetrating agent, it will remove that protective layer, therby damaging it eventually?
 

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nuppy

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spoke to a bloke from ebay selling bosch ones he told me the others are crap (susprise susprise!!) he's told me he can get me one for £175 plus £10 postage to spain so i think thats the one for me..
 

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Can you actually clean the delicate sensor (the tip) buy spraying a disolving solution? What about that oil on that small window?

I read somewhere that sensor had already a protective membrane/coating. If we use some penetrating agent, it will remove that protective layer, therby damaging it eventually?

The one in the picture is the sensor type where they eventually get out of spec


Alway check GSF and Euro as well as Bosch for the best price
 

bigasotonuk

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Have you had an MOT since you fitted it?

jib

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Yes i have had at least 2 MOTs since fitting the E-Bay MAF sensor and the emissions are perfect. I bought the E-Bay MAF before joining this forum and it was to solve an idling problem which it turned out to be a combination of dirty throttle valve, sticky throttle linkage. It might be there is nothing wrong with my old one but the car runs 'sweet as a nut' ATM
 


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