MAF cleaning

[shnazzle]

I was in the autoparts store the other week getting some bits and bobs. One of them was maf cleaner. Thought I'd get actual MAF cleaner this time, although I've always used carb cleaner.
The majority of staff are trained ex or existing mechanics and they all looked at me like I had a car growing out of my backside.

One does not clean MAFs it seems...

Now I've heard this before about hot wire MAFs being self-cleaning. But this is not obviously not always the case as our MAFs are known to foul and cause running issues.

Is the 1zz particularly susceptible to a dirty maf?

[jonbill]

I don't think so - Dirty MAF is a common thing on the BMW forums I visit too.
More like the people in the autoparts shop don't know much so  about cars.

[shnazzle]

That's the funny thing; you Google it and a lot of their story is generally supported. Also quite hard to find a maf cleaner
They're usually spot on.

Maybe by design they're self-cleaning but reality is different in some cases

[s12vea]

I was surprised at the difference it made cleaning the maf on my yellow one. It's one of the first things I would advise when purchasing a 2

[Essex2Visuvesi]

Most Maf Cleaners I have seen are Just IPA (IsoPropylAlcohol not the stuff made by Greene King)

[Topdownman]

I use switch cleaner.

I read that the test is to spray it on a window and make sure that when it dries it leaves no residue on the glass.

Its one of those jobs that I am always happier knowing that it has been done.

[shnazzle]

Exactly. I do ours twice a year with associated ecu reset
Even if it does nothing it makes me feel better  s:) s:)

[delhusband]

You'll be well aware of my level of knowledge here,
had never seen a MAF sensor until a few months ago, but before I cleaned mine the wires looked fine (IAT bulb was filthy though). Jase said the same the other day. Mine was at 63k miles when cleaned, possibly for first time?

Looking at the amber bulb on the MAF (the Idle Air Temperature sensor?) both front and rear, I got an idea of the kind of coating that can develop on these. That said, the elements inside the unit didn't look too bad - they looked a little dull maybe, but not black like the IAT

Wires OK, but bulb had a fair coating on it.

[Carolyn]

Self-cleaning MAF?  Right.  Anyone know where I can get a self-cleaning house?

[shnazzle]

Thought so...
It's definitely rubbish as I've seen first hand what cleaning a maf can do.
Just wondering whether it was particularly bad on the 2. Can't see why it would be. It's always going to be in approximately the same place in any car.

It'd have to be a pretty darn hot wire for it to burn off any deposits on the surface.

[delhusband]

But are there configurations/situations which make fouling more likely /worse? I'd read somewhere that oil impregnated performance filters can lead to MAF fouling quicker. What about difference between daily driver sat in traffic vs a car driven at high speed high revs most of the time?

[Ardent]

Exactly. I do ours twice a year with associated ecu reset
Even if it does nothing it makes me feel better  s:) s:)

Couldn't agree more  s:bowdown: :bowdown: s:bowdown:

[m1tch]

But are there configurations/situations which make fouling more likely /worse? I'd read somewhere that oil impregnated performance filters can lead to MAF fouling quicker. What about difference between daily driver sat in traffic vs a car driven at high speed high revs most of the time?

There were issues with VWs using hotwire MAFs and oiled filters, oil vapour from the filter would then collect on the MAF wire internally, the VW ECU was set to heat up the MAF as soon as the car starts and basically the oil on very fine MAF wire would basically fry.

I don't think the driving style would make much difference its more to do with the maintenance of the air filter letting through fine particles.

[delhusband]

But are there configurations/situations which make fouling more likely /worse? I'd read somewhere that oil impregnated performance filters can lead to MAF fouling quicker. What about difference between daily driver sat in traffic vs a car driven at high speed high revs most of the time?

There were issues with VWs using hotwire MAFs and oiled filters, oil vapour from the filter would then collect on the MAF wire internally, the VW ECU was set to heat up the MAF as soon as the car starts and basically the oil on very fine MAF wire would basically fry.

I don't think the driving style would make much difference its more to do with the maintenance of the air filter letting through fine particles.

Cheers M1tch  s:) s:)  I'd read something on K&N website where they say quite strongly that oil impregnated filters wouldn't cause fouling. Seen elsewhere suggestion that fouling could occur as a result of user applying too much oil to an  aftermarket filter. Wondered if forced induction exacerbated the problem. Bit beyond my ken, but I was curious because cleaning MAF is recommended easy maintenance job, when I went to clean my MAF it didn't look too bad (except IAT bulb which was filthy)

[shnazzle]

They do say on the site that properly oiling it won't cause issues. But it's a fine line between proper and over-oiled.

Mind, I ran with the oiled filter for ages and my maf wasn't any dirtier than usual. If anything I did have a tendency to overoil