MAF problem... please helpp

[-raj-]

hello,

The little orange fault light came up on my clk 230k, so i got it checked out and it was a fault with the MAF. ive been told by the garage that they can fix it all
in for about £350 using a genuine mercedes part.

My question is that can i replace the MAF myself as i was told by the garage that i could but the fault light on the dash would not disappear unless it is cleared by the special computer they hook up to the car.

Any infomation on this matter will be much appreciated. many thanks

 

[television]

Hello and welcome to the forum,, something not right here.

Your fault could be the camshaft magnet leaking oil into the wiring loom, this goes into the MAF,, gets burnt and the O2 sensor turns the lamp on,,the MAF will NOT turn on the engine lamp,, so check the MAF to see if it is oily

 

[-raj-]

ok thanks, all i did when the light came on is take it down to the garage and they hooked it up to computer and just said the MAF needs replacing. Is this incorrect then??

 

[Xtractorfan]

No.. the maf is showing faulty cos there could be a problem elsewhere, because the fault light is on there is a problem elsewhere.. get a second opinion.. try another garage..

 

[television]

ok thanks, all i did when the light came on is take it down to the garage and they hooked it up to computer and just said the MAF needs replacing. Is this incorrect then??

Yes that is incorrect just lift the air cleaner and see if the MAF is oily

 

[-raj-]

ok i had the MAF replaced and i asked for the old one back just to see what it looked like and it was OILY. Anyways the guy put a new one in and gave the pipes leading to the MAF a good clean but today the light came back on so im guessing it has to be the camshaft magnet leaking oil into the wiring loom (as said by television) beacuse the old MAF was oily. ill take it back to the garage to see what they say but have i just wasted my money on a new MAF or would it have still needed to be change if the camshaft magnet is leaking oil?

 

[television]

With a wash down with lighter fuel the old MAF should be perfectly OK

 

[-raj-]

ok thanks, is fixing this leaking camshaft magnet a big thing and will it cost alot?

cheers

 

[television]

ok thanks, is fixing this leaking camshaft magnet a big thing and will it cost alot?

cheers

Sorry Raj I do not know the cost,, shame that you bought the MAF that you did not need

Maybe some one else will know the cost

 

[Xtractorfan]

I think you were told that the problem wasnt with the maf..

 

[Cole@MBS]

Hello and welcome to the forum,, something not right here.

Your fault could be the camshaft magnet leaking oil into the wiring loom, this goes into the MAF,, gets burnt and the O2 sensor turns the lamp on,,the MAF will NOT turn on the engine lamp,, so check the MAF to see if it is oily

Sorry Malc, a airmass sensor CAN turn the engine light on, see it weekly young man!!

 

[television]

Sorry Malc, a airmass sensor CAN turn the engine light on, see it weekly young man!!

Its never been reported here before,, not in WIS only if the O2 sensor has shifted from stored setting

 

[Uncle Benz]

Fence sitting time for me again...

In my experience have seen faulty air mass sensors which HAVE caused the CEL to illuminate, and I have seen faulty air mass sensors that HAVE NOT caused the CEL to illuminate.

Seems to be no certain rule to it.

On another point, 230K engines with oil contamination of MAF can also be caused by blockage of 2 small brass breather stubs below the inlet manifold, part of the crankcase breather system. Worth a look too...

It is possible to replace a MAF yourself, but I always perform a 'Bootstrap' proceedure with MB Star machine to reset adaptation parameters. I don't know if it is strictly necessary, but I have never had any comebacks...

 

[television]

Fence sitting time for me again...

In my experience have seen faulty air mass sensors which HAVE caused the CEL to illuminate, and I have seen faulty air mass sensors that HAVE NOT caused the CEL to illuminate.

Seems to be no certain rule to it.

I think that in the service sector, one must not take anything as gospel,, something new all the time.

Thank you SAM and Uncle

 

[Cole@MBS]

The C,class and ml 270 cdi is the best for showing this up, others dont, but the 270 does always come up as a currant fault code, as for uncle,s reply, only really see that on the slk 170 when you replace the battery, you lose the throttle, so you have to boot strap it,!!!

 

[jimsinessex]

ok i had the MAF replaced and i asked for the old one back just to see what it looked like and it was OILY. Anyways the guy put a new one in and gave the pipes leading to the MAF a good clean but today the light came back on so im guessing it has to be the camshaft magnet leaking oil into the wiring loom (as said by television) beacuse the old MAF was oily. ill take it back to the garage to see what they say but have i just wasted my money on a new MAF or would it have still needed to be change if the camshaft magnet is leaking oil?

If the MAF sensor is oily then that does NOT come from the camshaft magnet which is a different problem affecting the ECU. An oily MAF sensor indicates you have the dreaded "oil in air intake" fault which can affect the 230K engine at mileages after about 70,000 - does that sound like yours? The problem needs to be tackled and is well documented on here and in the DIY section. Just cleaning the brass nozzles referred to earlier in this thread is not enough on its own. The whole of the part of the crankcase breather system hidden below the intake manifold needs to be replaced as pipes there get brittle and break, get blocked or a spring-loaded valve there blocks up. Parts cost about £20 but reckon on about 4hrs labour. The MAF sensor will oil up again and again until the problem is tackled. MB Dealers and Indies are often not very familiar with this problem and can lead you on a wild and expensive goosechase often suggesting the oil is coming from the kompressor - it is NOT!.

DO search on here for the "oil in air intake" thread started by Balal and also read the DIW thread by Jamesmc. All will be revealed.

PM me by all means if you wish, I spent a lot of time getting to the bottom of this problem.

Jim

 

[television]

If the MAF sensor is oily then that does NOT come from the camshaft magnet which is a different problem affecting the ECU. An oily MAF sensor indicates you have the dreaded "oil in air intake" fault which can affect the 230K engine at mileages after about 70,000 - does that sound like yours? The problem needs to be tackled and is well documented on here and in the DIY section. Just cleaning the brass nozzles referred to earlier in this thread is not enough on its own. The whole of the part of the crankcase breather system hidden below the intake manifold needs to be replaced as pipes there get brittle and break, get blocked or a spring-loaded valve there blocks up. Parts cost about £20 but reckon on about 4hrs labour. The MAF sensor will oil up again and again until the problem is tackled. MB Dealers and Indies are often not very familiar with this problem and can lead you on a wild and expensive goosechase often suggesting the oil is coming from the kompressor - it is NOT!.

DO search on here for the "oil in air intake" thread started by Balal and also read the DIW thread by Jamesmc. All will be revealed.

PM me by all means if you wish, I spent a lot of time getting to the bottom of this problem.

Jim

I can vouch for all of the above and I will never forget it and the work and searching that went on, I have referred people to it directly many times,, thanks Jim

 

[-raj-]

ok i took it back to the garage and they hooked up to their computer again and it said there was a fault in the MAF again, which was not ture as i had it replaced by them just a few days ago. They also checked if the camshaft magnet was leaking oil and it was not, they said it was very good. Anyways a genuine MB engineer was called down and he hooked up his laptop with all the latest software and found no faults what so ever and cleared the engine check light. He even said the car was running very well. So hopefully fingers crossed it is all sorted now.

i would just like to thank everyone at mercedes benz owners forum for all help and infomation, it was much appreciated and has helped me alot to understand my mercedes.

thanks Raj

 

[carabind]

Let me get my head around this. The garage's computer says it needs a new MAF. The MB chappie's lap top say no faults......so which one do you choose?? Surely one is wrong?

 

[Mark A]

The C,class and ml 270 cdi is the best for showing this up, others dont, but the 270 does always come up as a currant fault code, as for uncle,s reply, only really see that on the slk 170 when you replace the battery, you lose the throttle, so you have to boot strap it,!!!

No Always.

The wife's ML didn't come up with a fault light when it was running badly (no get up and go/ wouldn't rev). I bit the bullet and changed the MAF and hey presto. When I then bought my code reader the failed MAF code was in there as it hadn't been cleared.