Can Oil Overfill damage MAS Sensor

[andreas_t]

Folks, I'm after a bit of advice. I have a 2001 E220 CDI (82K miles) which seems to be demonstrating all the problems of a failed MAS sensor (very sluggish off the mark when cold, rattly when hot or cold). I am about to take it to the dealer for a check (and bad news). I am however wondering what caused it: the car went in or a service about 3K miles ago - following that, it complained that they had overfilled it with oil (this is the second time the have done it in the last 3 services - why am I still going there ?) - took it back to them, they sucked it out and sent me on my way. It may be coincidence, but the problem I have, seems to have started at the same time as the engine oil overfill - could the two be related ? - Shall I be blowing a gasket at the dealers ? (I'm quite good at losing my temper !).

Any advice would be appreciated.

 

[SimonsMerc]

George Fraser once told me that overfilling could be the cause of a MAF problem, but I don't know any more than that. I'm sure someone more knowledgeable will have details

-simon

 

[andreas_t]

Simon, Thanks for the quick reply - I'm eagerly awaiting guidance from anyone else out there. While I'm at it, does anyone have details such as location/phone no. of Steve the 'wizard' - I've seen his name quote a few times in posts, but have no other info.

If I'm going to have to change the MAF thingy, I might as well get it done by someone who knows how to treat my baby !

 

[Steve_Perry]

Moving to engine section...

S.

 

[Robbo]

Did they change the air filter? sometimes debris from the filter can get onto the MAS and cause it to malfunction. I read somewhere that they can often go after services due to this reason.

 

[Satch]

Did they change the air filter? sometimes debris from the filter can get onto the MAS and cause it to malfunction. I read somewhere that they can often go after services due to this reason.

You are right and some engines are more vulnerable to this than others.

According to VAG many of the failed MAS coming to them as warranty claims stem from "incorrect procedures" when changing air filters. But many other returned units are found to be still fully operational when tested.

I can see how oil overfill could be a problem if a breather pipe is located upstream of the MAS.

 

[Will]

I would say that it's very possible, my reasoning being that if the breathers vent into the airbox, this could be 'inhaled' as air is drawn into the engine, past the MAS.

Also, as others have noted, in removing the air filter, debris could be dislodged and sucked through onto the MAS also.

Good luck,

Will

 

[andreas_t]

Folks, thanks for the replies.

In as far as the air filter is concerned, yes, it was a service B and they changed quite a few things, including the filter. The problem was that the overfill will have affected the new components .....

I think best thing to do is for me to get under the bonnet and see if I can make out whether oil residues or other deposits have been the cause of it. Then I can take it from there. I probably won't win this battle with the dealer, but I will certainly make a lot of noise if it turns out to be related to the oil overfill.

As a final point: does anyone have the location/contact details for Steve ? - I couldn't find them in any of the posts on the forum.

 

[silverarrow]

yes too much oil can damage the mas a thin oil residue gets on the sensor i would suggest that you have a look at www.bba-reman.co.uk and send your mas for a check you can order a sensor from a bosch agent for about £125 all in
give them your bosch num

 

[Dieselman]

yes too much oil can damage the mas a thin oil residue gets on the sensor i would suggest that you have a look at www.bba-reman.co.uk and send your mas for a check you can order a sensor from a bosch agent for about £125 all in
give them your bosch num

It's a CDI. The MAF is about £50 all in.

 

[andreas_t]

Would you say it is best to do a check of injectors/airflow first, or just go ahead and change the MAS ?

Checks first, means about £90 - and no guaranteed instant fix. MAS first means possibly £50 (where from, Dieselman ?) plus fitting.

Thoughts ?

 

[Dieselman]

From the MB dealer. They might fit it for you, alternatively you can do it yourself in about 2 minutes.

 

[andreas_t]

Thanks guys - good, helpful comments all round.

I'm taking it over to Steve at SPR in a couple of weeks and will let you know how it turned out.

 

[jeremy156]

So, £230+VAT for a replacement MAS for my 1998 E320 V6 (petrol) from an independent..... sounds like I was ripped off, right?

 

[stats007]

In a word, yes

 

[andreas_t]

Latest on pricing: MB Coventry want £174 + VAT to replace MAS. More quotes coming soon .......

 

[andreas_t]

End of the MAS and the oil-ovefill saga ......

Took it to Steve (a true gentleman) at SPR Autos who run the diagnostics - no fault codes, but misfire quite bad by now .... so took it to the stealer who diagnosed 2 injectors 'out of limits' and a 3rd one about to go ......

So, 4 injectors to change and my gasket blown ....

However, this did the trick :bannana: - MB decided to 'split the cost' with me paying for 50% (£597.25) of the damage. So, not entirely happy, but at least not 100% out of pocket.

And she goes like a rocket

PS. The motto of the story is: always use a good diesel additive even if you fill up at Shell or BP (which is what I've done for the last 4 years). Isn't retrospective knowledge invaluable, eh ?

 

[mobeyone]

End of the MAS and the oil-ovefill saga ......

Took it to Steve (a true gentleman) at SPR Autos who run the diagnostics - no fault codes, but misfire quite bad by now .... so took it to the stealer who diagnosed 2 injectors 'out of limits' and a 3rd one about to go ......

So, 4 injectors to change and my gasket blown ....

However, this did the trick :bannana: - MB decided to 'split the cost' with me paying for 50% (£597.25) of the damage. So, not entirely happy, but at least not 100% out of pocket.

And she goes like a rocket

PS. The motto of the story is: always use a good diesel additive even if you fill up at Shell or BP (which is what I've done for the last 4 years). Isn't retrospective knowledge invaluable, eh ?

What did the stealer diagnose that steve could not?

I took my car to him about a misfire and he also could not find anything at fault and i have changed my maf. I have a feeling my purge valve maybe a cause as when this starts to tick my engine feels a little stressed but when quiet all is ok.

I am planning on oil changes every 5000 miles and using additves every 2000 miles so lets hope I do not go down this road!

 

[tamrsoft]

Before replacing MAF, try removing it (simple job when done with care) and cleaning it with an electronic components aerosole spray. I found that mine was covered in an oily film and did the job in about 10 mins. You can buy the spray from Halfords. Do not use Carb cleaner or WD40.

 

[andreas_t]

Mobeyone,

Steve did the diagnostics on mine but it was not showing any fault codes - so he concluded that it was a mechanical problem and I needed an engine prssure check.

The stealer - apparently - can check the condition of the injectors. A few injection specialists can as well, but they would probably be guessing what the right values are. For info, and from memory, I think the stealer had quoted me £92 + VAT to run the check; an injection specialist wanted £70 or thereabouts but could not guarantee the result.

The problem I had was the car being very hesitant when cold, then Ok when warm, but really thirsty (from 46mpg down to 37mpg over long mway journey). And misfiring from idele up to 2500 revs - but not smoking or anything else.

Hope this helps you.