cleaning the MAF SENSOR

[biztrick]

hey guys,

i found this write up on how to clean the maf sensor for our cars, this is the link http://hubpages.com/hub/clean-replace-vw-audi-maf-diy ... do you think its safe to do this, and will it actually make a difference in MPG?

[awdjunkies]

Funny, I found that same one about 2 weeks ago and tried that and nothing. Maybe you will have better luck.

[vannyhuj]

Wow, that person made it much tougher than needed. I did this to mine and I used MAF cleaner, not rubbing alcohol. Also you don't have to remove the MAF from the housing, you can spray the MAF while it is in the housing. If you do want to remove the MAF, don't use vice grips to remove the screws, you can buy a set of tamperproof/security torx bits for about $10. Not sure about a huge difference in MPG, but it wasn't the reason I cleaned mine. I didn't notice a difference in my MPGs from this.

[dmaxn]

I used CRC Mass Air Flow Cleaner from Advance Auto. Dont know if they have this is Toronto.

[Pr0n]

You can find CRC MAF cleaner from NAPA (call ahead, as they may need to order it), otherwise, you can go to Canadian Tire and use their Electrical Contact cleaner.

[awdjunkies]

Wow, that person made it much tougher than needed. I did this to mine and I used MAF cleaner, not rubbing alcohol. Also you don't have to remove the MAF from the housing, you can spray the MAF while it is in the housing. If you do want to remove the MAF, don't use vice grips to remove the screws, you can buy a set of tamperproof/security torx bits for about $10. Not sure about a huge difference in MPG, but it wasn't the reason I cleaned mine. I didn't notice a difference in my MPGs from this.

See, I tried it with MAF spray + w/out removing the sensor and that didn't, so I reverted to this method( except I used the Security Torx as well). Only reason why I was doing this was because I was getting a code.

PS: Just noticed you are in Reno as well.

[b7kevin]

Took maf out grabbed 100% rubbing alcohol and placed it in a zip lock bag. Gently swished the solution around to clean the MAF. The fluid was quite dirty when I was finished.

[awdjunkies]

Took maf out grabbed 100% rubbing alcohol and placed it in a zip lock bag. Gently swished the solution around to clean the MAF. The fluid was quite dirty when I was finished.

Well then, there you go. At least it worked for you.

[LampyB]

the MAF sensor is very sensitive, i wouldn't recommend the plastic baggy approach. all that's needed is what was said above...buy some MAF sensor cleaner from Autozone or your local auto parts store and spray it down well while still in the housing. make sure its completely dry before reinstallation and starting the car. it isn't meant to increase horsepower, but when you're in the 75K+ mileage range cleaning the sensor will extend its lifespan and possibly regain both power and throttle response lost due to a dirty sensor.

on my B5 A4 i reached about 95K miles and the car was really bogged down under WOT, accelerating up mountain passes in colorado was a major struggle. i cleaned the MAF and it made a huge difference. about 5K miles later it went bad entirely though, so it is what it is...simply cleaning the part to remove dirt and grime.

EDIT: and why you would use vice grips to remove the housing screws is beyond me, go buy a set of tamperproof bits and just unscrew. vice grips just sounds like a pretty retarded and lazy last minute approach to cover for not being prepared.

[DenverDubbin]

vice grips just sounds like a pretty retarded and lazy last minute approach to cover for not being prepared.

LampyB,
I wrote that DIY, and if you actually read it you would understand that there is nowhere local to buy 5 point tamper proof torx bits in Colorado. I tried Napa, AutoZone, Checkers, Advanced Auto, Lowes, Home depot, Ace hardware and Harbor freight. At all of them you can buy 6 point bits, which will work on some VW/Audis as I posted in the DIY, but none of them sell five point bits which I believe to be a VW specific tool.
In the diy There are links to where you can buy the bits online, short of that there is no where in Colorado that they can be bought and if you argue with that then please post up where for a future reference.
Also what's your reasoning for not recommending the plastic bag approach? Nothing touches the sensor but alcohol.
My using vise-grips then replacing the bolts with phillips head for easy access the next time the the maf needs to be cleaned is far from "Lazy" or "Retarded" as you so put it.
Vannyhuj, I didn't mean to write it to be more difficult than what is needed. I just wrote it in full detail for people starting out that are hesitant on working on there cars. When I'm working on something new I like the idiot's guide of everything, so that's how I try to write my diy's. I'm just trying to help people save money and not be scared of what's under there hood.

[matt94gt]

Going to clean my MAF soon, in the past on my other car I just use electrical contact cleaner and have used isopropyl alcohol before to clean sensors in the past and was told to use this on my MAF last time I was in the local NAPA, will look around for this 'maf cleaner' that you speak of...

Thoughts on using isopropyl alcohol?

[redcon1]

Haven't doe this on the B7 but have had success cleaning my Mk4 VR6 MAF with Alcohol/Ziploc bag method. The concensus among VW dudes is to go to a drugstore and by 99% Isospropyl, not the 91% you can pick up in the grocery store.

[matt94gt]

Yeah 99% is what I have used for a number of things.

[BoSNiaN]

So I bought the 99% stuff ($5 for 500ml but OK), so should I disconnect the battery, or the maf cable completely, or is it fine to just disconnect it enough to route it into a ziplock bag and swosh it around in the solution?

[BoSNiaN]

So I bought the 99% stuff ($5 for 500ml but OK), so should I disconnect the battery, or the maf cable completely, or is it fine to just disconnect it enough to route it into a ziplock bag and swosh it around in the solution?

UPDATE: Did it today but I don't notice any big changes in the way my car drives....Took it to a local shop the other day and the tech drove it and he said its really peppy for a stock 2T so maybe its already in good shape...Anyway, few things about that guide:

1)You need T20 anti-tamper bit. Its basically a torx with a hallow center, I bought a set locally for $15 but I'll be returning it tomorrow because I don't think I'll ever need it again

2)No need to disconnect the TIP hose, or bend that clamp. You do need to remove the airbox stuff sitting on top of the MAF, undo the clip for the wire connector, move the connector away, undo those 2 screws, and pull out the MAF. I swoshed mine in a ziploc with 99% for about 5 minute but the color didn't change or anything so it must have been clean already (although I could see dirt around the sides). Let it dry for 10-15min and reassemble. The bolts can be resused. Go for a drive and make sure you don't suddenly get a CEL because you may have damaged something.

Is the MAF prone to static damage? I thought I would throw a CEL after I put it back because I used a regular shop towel to clean up some dirt after it had dried and then dropped it in my engine bay (about 3-4 inches) too before I managed to put it back in...No CEL though and I don't I'll ever bother to do it again

[groundround]

in the article it said to unplug the maf and go for a drive, did anyone do this or try this? you would think without the ecu getting a signal at all it would not drive well like the article says?

I am throwing p0171 and seeing i have 117k i think it is the maf, or O2 sensor.

[Schweini]

in the article it said to unplug the maf and go for a drive, did anyone do this or try this? you would think without the ecu getting a signal at all it would not drive well like the article says?

I am throwing p0171 and seeing i have 117k i think it is the maf, or O2 sensor.

NECRO BUMP

I unhooked my MAF and took it for a spin, the car felt bloody amazing. I haven't had that kind of throttle response since the first day of my tune. I'm now actually hitting the proper psi (22-23). Plugged it back in, the car felt sluggish with minimal throttle response and the psi never went past 17.

Anyway, needless to say, my MAF is obviously dirty as hell or on it's last breath. I'll be cleaning it tomorrow with this method to see if anything changes

For the record, I'm at 68,000 Km, with a K&N oil filter. The filter was dropped right in without wiping excess oil.

[Schweini]

.. just curious actually, how far/long can one go with the MAF unplugged? I've been reading that if you're a yr 2000 +, the MAP will take over and you should be ok. The MAP probably isn't nearly as accurate, but in the meantime if cleaning it doesn't work and I need to buy a new one, can I enjoy the car while being MAF less? Obviously while keeping the boosting to a minimum. It's fun as shit driving with it unplugged, I never knew just how bad my MAF actually was. I have my car back ...

[CorneliusRox]

You'll be fine but you wont have traction control, and you will make slightly less power and have slightly less throttle response because the computer has to do more calculations and guessing basically. No damage will come from it though!

[Schweini]

perfect, that makes everything more assuring. Thank you Corey

[218army]

Hey guys-

I have been trying to find out why my car has been running like shit at high elevation. The idle bounces like crazy and the vacuum reading is 10 HG from what it should be. When I return to sea level, everything is fine. I replaced the N80 valve, Cleaned the air filter, and now cleaned the MAF. None of these things have had any effect on the altitude issue. Interestingly enough, I think cleaning my MAF has cause another problem, as now my car is over boosting. before cleaning the MAF, it would spike 22 and settle at 19 PSI. Now, it's spiking at least to 25 but that's as far as my gauge reads. I am wondering if I screwed up the MAF when cleaning it. I had the right torx bits so i removed the sensor from the housing. I used MAF cleaner, spayed the whole thing in and out. I used a clean rag and wiped off the metal plate and around the plastic opening where the air enters. It was quite dirty, but I am wondering if touching it was a bad idea. Since its the only thing I changed I am thinking of just buying another sensor and a dry filter. HAs anyone else had any negative consequences of cleaning the MAF?

[ddillenger]

Who did your tuning? There are maps specifically for changes in barometric pressure due to altitude changes. Sounds like your tuner neglected these.

[218army]

Its a GIAC tune that I got from TAG Motor sports in San Diego. I frequently drive from sea level up to 9,000 feet to go snowboarding. Could I get a file that would normalize this over that whole Altitude range, or do you mean I would need to get 2 Maps and a program switcher? This was only ever an issue after I went to STG 3. When I was stg 2 plus up in the mountains I had no idle issues