IIRC none of our cars use the hot-wire MAF. All use the hot film MAF which is much less....

I'm going to open the engine cover of my 08 to take a look and clean it if it needs cleaning. What else might I do while I have it open? I am not much of a dyi guy, but I figure I can at least change the ailr filter and check the power steeing fluid (I think it is located there). What else is easy to do and check?

Also, I need to purchase a torx wrench. What size?

Thanks, Bob

1999 Arctic Sivler/black/black (sold)
2008s Silver/black/black - so predictable
2011 Outback
8/24/2011 first Grandson

You can check the PS fluid. That's how you would get access to the MAF, but unless you are seeing a problem.....

MAF cleaning is on my rainy day list. Just not above boring essentials....

Off to change my oil B4 mid ohio

It will be a "fridge leftovers" mix of Syntec 10w40, M1 15w50 and edge 10w40 - i have about 2qts each of the first two.

Love the marketing guys at Castrol. They now have edge with syntec technology (aka improved syntec but not really edge)

Grant

is that something that is pretty straightforward to do? I haven't looked, but I assume I can go to Pedro's site to see how to diy.

The MAF ( mass airflow sensor) sits in a protected (usually) part of the throttle body and measures the air so fuel can be metered accurately.

Truth is, you clean the whole throttle body. You take it out, and basically spray MAF cleaner through it to get all the accumulated dirt, carbon etc buildup off both the inside, the moving part( the butterfly) and the hot-wire sensor.

Crud accumulates on it from air intake. How much depends on pollution, where and when you drive, and whether you added anything upstream that might deposit oil on it (e.g.: an over-oiled foam air filter).

It can be instructive to open it up and see - if its shiny, you learned something, and if its cruddy, it was a good idea.

I have not had mine out. Its a bit awkward to get to as i recall - not much more.

Grant

I never had any problems with my car till I cleaned the MAF with Maf cleaner.

I would not touch the MAF unless you have MAF issues. Cleaning the throttle body is fine I suppose, but again not needed IMO.

Why even clean the area? Nobody can see it. I only clean non-visble engine parts when I have an oil leak or the like, that I need to be able to track down. Its always easier to track down leaks on a clean engine.

as deposits bu8il on a hot wire, it reacts less linearly. Similarly, the throttle body - mostly the butterfly - can build up both dirt and carbon tracks, especially where the butterfly sweeps and comes to rest. This can interfere with its action. On fly by wire cars this can even cause - eventually - a "implausible throttle angle" error which means that the butterfly is not where the stepper motor thinks it is - and that means that there has been a creeping error in air/fuel metering for some time. How cna you know? You cant, unless you look. And in the case of the hot wire itself, i dont think looking will help.

So i would be cautious, yes, but i think this can be a good area to do some preventative maint. I plan to.

Grant

sensitive to being affected by anything coming along for the ride in the intake air stream.

I don't know where you live and drive but where I live and drive none of my cars' MAFs have ever needed cleaning. All my cars have had their factory intake systems left stock, too. I've cleaned them a few times simply to see if they're being dirty was the cause of the symptoms. No dirt to speak off from the MAF and after the cleaning the symptoms were still present.

Sincerely,

MarcW.

S4. That's the bi-turbo small V6. The MAF was fine, but the throttle body got fairly junked up and caused the fly-by-wire to go haywire. Apparently the butterfly, each time it returned to "rest", dragged a small amount of dust/dirt/etc with it until a ridge built up. Cant say exactly what happened but metering was off, and the stepper motor's position did not match the input signal, ergo it threw codes and went into limp mode.

Gummout in fact fixed the problem, but i'm told that is not the advised cleaner.

As to the the hot wire (hot film, ok, I don't know much about the idiosyncrasies of each) all i know is that lotys of them get replaced, both here and in Audi/BMW land. So i assume that they are getting fouled the same way. Maybe not. But i cant see where cleaning - if gentle - isn't at worst neutral and beyond that a good thing.

Thanks for the advice.

Grant

I tried to take my MAF out today because the car is having slight idling issues. I also wanted to clean the throttle body as it builds up a lot of dirt and can affect the performance.
It looks like a big job to strip out the throttle body, has anyone removed the throttle body and if so was it difficult?

My engine is not the same as in Pedros throttle body DIY, it is the same as the engine in this link
[www.pedrosgarage.com]

recall the exact steps.

I do recall it helps if the intake is warm cause it makes the hard plastic intake tube more pliable easy to get back on the TB. I even resorted to using a bit of vegetable oil to lubricate the intake tube to help it slide onto the TB. I didn't have one but had I had a heat gun I think I would have used it to heat up the intake tube even more. It was cold (mid-Feb in the KC Mo area) when I did this and the intake cooled right down even in the garage after I removed it from the warm engine.

Be careful handling the TB. If you drop it....

Also, if you find the TB dirty and repeatedly so, this is based on my experience not normal. The only time I removed and cleaned the TB was when I was trouble-shooting an idling problem. The TB was dirty, oily dirty, and the cause was from a failing AOS. The AOS connects to the intake manifold right behind the TB and the AOS was working so poorly the oil vapor it passed into the intake was fouling the TB *upstream* of where the AOS connected.

Sincerely,

MarcW.

At 90K miles, I just replaced the air filter and the MAF, because I was getting a lot of error codes. The new MAF seems to have done the trick for me.