Cleaning the MAF

[ddave05]

Alright guys. Thinking of taking the MAF out for a good cleaning, as i feel the car is a bit underpowered at the moment. Everything else on the car is ok, it's had long life servicing throughout ownership and never missed a beat. It’s a 04 TDi 130, with about 60k on the clock. The same thing happened to my old B5 and the MAF made a world of difference.

I was just wondering if anyone out there has done it themselves. I have bought some iso alcohol 99% but was just wondering how long I should leave it in there to 'soak'. Is it likely to cause damage to the sensor wires if I leave it for a prolonged period?

Also, I can't find the bloody 5 point torx security bit anywhere so i think ill have to take the whole housing, including the case off in order to clean it! Does anybody know of a supplier of these security bits. Checked on ebay, i suppose that could be an option but very few sellers have the 5 point bits.

[passat 130 tdi]

i drilled the centres out on those bolts , i then used a small torx headed bit and tapped it in the hole with a hammer once loosened out so far i used small molegrips to get them out , i replaced the 2 bolts with self tappers of the same size thread with a posidrive head .


i cleaned my maf 2 weeks ago , i just sprayed mine twice left it for 30 seconds and let it dry in the wind . i didnt soak it .

[ddave05]

Cheers for that. Did it make any difference to the power/economy of the car? I sprayed my last one too, but this time i have bought the alcohol in liquid form. I think im going to use the "Ziplock" bag method where i dip it in the alcohol and swish it around for a bit then leave it to air dry for a couple of hours on my windowsill.

I may just replace the torx screws with something simple like a phillips head - just need to make sure i find the right fitting one so as to not damage the current housing. If there's one thing i've learnt, its that plastic trim parts scratch/damange too easily!

[passat 130 tdi]

seems to be smoother now , mpg is improved slightly say 4mpg on a 20 mile trip at 2ooo rpm .

[Luffers]

I went to clean mine today and came up against this same problem with the torx screws!

Do standard garages have these torx bits to undo the maf or is it only VW dealers?

Is it not possible to buy the torx bit from somewhere?

[martin1810]

The 5 sided security torx bits are not that hard to find. Just ring round a few shops or motor factors. They can be bought as 1/4" screwdriver insert bits.

[ChillOut]

The 5 sided security torx bits are not that hard to find. Just ring round a few shops or motor factors. They can be bought as 1/4" screwdriver insert bits.
Screwfix do (or did) a set of all the weird security bits including these. The set was really cheap - under a tenner I think. Not built for daily use, but for the DIYer, perfectly fine.

[Robbus]

Hi,
You need something like this:
http://www.justoffbase.co.uk/TRX-TS-Security-Bit-Set-7pc-1-4Sq-Drive-Sealey-SX106
http://www.pvrdirect.co.uk/productinfo.aspx?catref=AK6178

Th 5 point bit is known as 'Torx Plus Security', bit tricky to track down! Can also google for 'TRX-TS', I dunno what size bit is needed though as I've not delved under the hood enough to even find my MAF!

Cheers,
Rob

[Luffers]

Cheers Rob, top man!

[cazyp]

Same screws are used in a lot of computers.
I got my set from Maplins.

[martin1810]

Just a note. The normal security bit sets don't contain the five sided ones. Trust me I sell tools.

[cazyp]

Just a note. The normal security bit sets don't contain the five sided ones. Trust me I sell tools.

Never trust a man who flogs tools all day LOL! :D
Only joking - listen to Martin.

[passing]

I went to clean mine today and came up against this same problem with the torx screws!

Do standard garages have these torx bits to undo the maf or is it only VW dealers?

Is it not possible to buy the torx bit from somewhere?

aldi do a superb set of bits including these "security" bits for £5.99 when it is in stock

[bohoo]

they are a t20 in size

[Eshrules]

pssst....

I've yet to see a successful MAF clean happen.

I'm not sure what you're spraying these things with, but best bet is to buy new. You're not eliminating the possibility of the fault, you're introducing a new variable.

[passing]

i would agree with cleaning not being the route for long term solution but in the short term it can hel;p demonstrate where the problem is.

I use hot wire anemometers (the same basic technology as in the original MAF) for work and when the wire starts to corrode it is shot. If the dirt sticks to the wire then it introduces corrosion too through trapping moisture or pollutants and the corrosion is then rough so that it also encourages the crud to stick.

Hence when I found the Pierburg for myself it was attractive as it uses a hot plate meaning a greater surface area and so I believe it will be less susceptible to corrosion influenced changes in resistance.

[Paul Jay]

Agree with the above. Cleaning the Air Mass Meter (or MAF as VAG call it) seems to be rarely successful in the long run.

They are notoriously fickle and cleaning seems to do more damage than good in the main, although there have been some success stories on here.

Replacement isn't too expensive (usually about £70 exchange for a genuine VAG one) and you might also get the 2 year warranty, although I might wrong on that one.

The cheap pattern parts on eBay are best avoided too it seems, as they just don't last and have been known to cause all sorts of running problems.

HTH

[ChillOut]

Agree with the above. Cleaning the Air Mass Meter (or MAF as VAG call it) seems to be rarely successful in the long run.

They are notoriously fickle and cleaning seems to do more damage than good in the main, although there have been some success stories on here.

Replacement isn't too expensive (usually about £70 exchange for a genuine VAG one) and you might also get the 2 year warranty, although I might wrong on that one.

The cheap pattern parts on eBay are best avoided too it seems, as they just don't last and have been known to cause all sorts of running problems.

HTH

I got a cheap one from GSF - about half price of VAG. The car ran terribly - bearly idling and puffing out smoke. I put the old one straight back. Still have the problem I started with, but nothing like as bad as the with the cheapy MAF.

I might just give up and let VAG diagnose me for £80 - getting a bit brasse off really - Demon Tweeks let me down and never send the vac pipe, GSF sold me a dodgy MAF.

I need the car back to 100% ASAP or I will go and buy a Honda - and that WILL be expensive, so an £80 diagnostic fee may be cheaper in the long run (much as it galls me to admit it).

To return to the topic - I would say that if cleaning proves to cure a problem, you'd be better then getting a new one from VAG as others have suggested.

[Paul Jay]

There you have it really.

Crasher is the expert on this sort of thing and I'm sure he'd recommend a fault code read first and if nothing is shown, a new AMM from VAG.

HTH

[passat 130 tdi]

what kind of mileage range does the maf become problamatic - mines done 95k and still ok .

[Paul Jay]

There doesn't seem to be any limit. Some last zillions of miles and others hardly any.

There could be a poll here!

[cazyp]

Mine just done 170'000 last night, still ok.

[syncromonkey]

Hi guys, I have a Passat 2.8 V6 Syncro and have been having some big problems with the idling. I have up until today had a Forced induction filter on the other side of the MAF but thought that this may be the cause of the problems and have re-fitted the old air-box this morning... Much to my dissapointment this has made no difference...

If i run the car without the MAF connected it seems to idle a little better but not a great improvement however if i plug the MAF back in the car nearly stalls...

Does anyone think that I should just replace the MAF or try cleaning it using one of your discussed methods...?

Your help would be much appreciated on this one.....

[cazyp]

Get a fault code read. It could be a small number of things.

[syncromonkey]

That was going to be my next port of call tomorrow, what else could it be then if not the MAF?

[Paul Jay]

Could be temp sensor, injector loom, allsorts really. If the car runs differently with the AMM (MAF) disconnected this sounds like a major suspect.

A fault code read should tell you much more, but if no faults are logged the AMM is a strong favourite.

HTH

[syncromonkey]

Thanks for your help chaps, I am going to try and get it in for a fault read tomorrow... I will let you know how i get on...