Cleaning the MAF sensors..? Seems that we don't need to be buying MAF sensors all the time..?

[AC_ML]

Cleaning the MAF sensors..? Seems that we don't need to be buying MAF sensors all the time..?

I was browsing another MB forum and I found a post were they described how to clean the MAF sensor. It seems that it is just dirt on the sensor wires what causes the MAF sensor to fail or work incorrectly and that cleaning it correctly is enough to restore it's function. Which makes technical sense all around.

Has there been a post in our forum on cleaning the MAF sensor..? Seems that it will save use time and money to know how to clean our MAF sensors correctly..

AC

// The actual full post http path is:
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http://forums.%6dbworld.org/forums/showthread.php?s=1f5438109ced78f4b267b09a84bf3a1f& threadid=61940

http://forums.%6dbworld.org/forums/showthread.php?s=15525c4a737333333293d375aef153e9& threadid=61940&perpage=10&pagenumber=2

// The http path to the MAF article is


http://www.lexusownersclub.co.uk/knowledge/index.php?page=index_v2&id=50&c=9


// Appended post from

I did some research over the internet and found a pretty good article on how to clean MAFs. The article's for a Lexus though...couldn't fine an article on how to clean the MBs Bosch MAF sensor, but this article helped.

http://www.lexusownersclub.co.uk/knowledge/index.php?page=index_v2&id=50&c=9

Jotted down a list of things needed to do the job and painstankingly with a lighted magnifying lens, carefully cleaned the sensor wires (without touching them...just spraying and letting the cleaner sit on the wires for a while)..then drying them with a compressed air can.

After 2-3 cleanings the shine on the wires was back - the dirt all gone.

Plugged the MAF back in the truck...and took it for a 50 mile test drive...the mileage started climing back up to normal from 12.6 mpg to 21 mpg on the freeway and then as I drove it back in the city it fell to about 18 mpg....it was reading 17.8 when I finally parked it in my driveway after the 50 mile test drive.

I really wish I could post the pictures...but IS ANYONE EXPERIENCING THIS 1 byte attachment problem? WHY CAN'T I ATTACH IMAGES to POSTS?

Question: My other car, a Nissan Maxima with 150,000 miles has never had a change of its MAF...my uncle's 4runner at 107000 miles hasn't needed one cleaned or replaced?

Why does this have to happen only to MBs (or should I say only MLs????)

That article also by the way recommends cleaning the MAF sensor every 20,000 miles/2 years as preventive maintenance...


Last edited by mihir_d on 03-01-2004 at 03:05 AM

In fact, as I was driving today, I noticed my mileage improve further to 18.2 in city, which I believe is because the PCM is gradually self adapting to the now more accurate and correct sensor readings.

As for the clean up job:
To make things worse, the sensor wires on this Bosch sensor are lined up perpendicular rather than horizontal to the slot from which they are accessible. That makes it impossible to be able to touch them in any way...(which in fact is good, since one is most likely to damage the wires by touching them)...I can now very well understand why it is so easy to damage the MAF sensor wires...they are sooooo delicate..

Unless, one has the right tools and cleaner, it is very easy to damage the wires.

Since getting physical access to them was not a possiblity, I sprayed them with the throttle body cleaner and let the wires soak in the cleaner for a while thru each cleaning cycle. Then dryed them with a compressed air can.

At the first cleaning the difference was not visible, but after the 3rd cleaning the shine on the wires was restored & the difference was obvious. As I said, I used a lighted magnifying lens to inspect the wires.....that helped a lot to see the difference.

I have never used an aftermarket air filter nor intend to....again as I said, I have maxima with 150000 miles on it and it has never had its MAF replaced or cleaned...wonder what's up with these MLs...

I too am a bit skeptical about this being a long term fix, at least for now. If the mileage drops again, or if I see other MAF related symptoms, I guess, I will have to replace it, but if the clean up job worked....I would recommend, cleaning the MAF every 20,000 miles as per what that site recommended...

Total cost of tools needed for this repair was $20

I will post a picture of the clean up job shortly along with all the tools that I used for it..


Last edited by mihir_d on 03-02-2004 at 03:05 AM


1. Special bits for unscrewing the sensor from the casing.
2. Spray can of Throttle body cleaner or equivalent
3. Air can
4. Box cutter
5. Screw Driver
6. Flash light/magnifying lens
7. Tooth brush
8. A clean towel to lay things on..



The whole project took about 30-45 minutes

Here's a close-up of the sensor wires..




Last edited by mihir_d on 03-02-2004 at 05:43 PM

[Benz4Dirt&Sky]

[:D]

[jdbower]

[jdanish]

This all seems new to me, as I have said before, the MAF heats an element to a given temp and then checks the air flow based on how cool the element gets. not sure any cleaning will fix a failed element. Reason for failure- heated element breaks due to constant heating and cooling.
jd

[AC_ML]

Maybe short term failure is dirt and long time failure is burnt out..?

There shouldn't be any reason for MAF sensors to fail before 100K miles. That kind of failure will be a serious design flow and Bosch and other manufacturers have been designing these sensors for some time and will normally design this element with a much longer lifetime than that. Maybe there is too much currrent or much voltage applied to the elements and are being burnt too soon..?

Maybe people that have changed (or need to change) their MAF sensors can check their old sensors and see if the sensor wires are burnt out or just plain dirty. Maybe the filter composition is shedding microscopic filter material that tends to stick to the wires..?

I use K&N filters and never had a MAF sensor problem. Have any K&N ML users have had any MAF sensor problems..?

AC

[tcp_ML500]

Let's see if we get a snowball effect out of this

[tcp_ML500]

This is the Bible Belt, Baptist country, land of dry cities and dry counties.

I do not wish to be lynched at the end of the movie in a misguided retaliation!

[dfskinner]

Hey I saw the Passion and beat up the people protesting in the parking lot, told them if they were going to use they 1st amendment right to protest, I was going to use my 1st amendment right to punch a couple of people..... just kidding, but the movie was pretty good, and didn't have any mudslinging afterwards...

[PAPARICK]

Found it informing that the air flow sensor could be cleaned. Saved about $300.00 by doing this. Mechanic quoted $300 plus labor to replace sensor. As for the special tool to remove screws I just used my dremel tool and ground down flat spots on both sides of the screws and removed them with pliers. Worked great. Car runs good again with 109,00 miles. Thanks for the cleaning tip.

[fabbrisd1]

This has been a common topic here... a "dirty" MAF will show up in somewhat rough idle, or when pulling to a stop will feel like the engine is going to shut off/too low idel, in extreme case show up as CEL..

Using a correct MAF cleaner (such as CRC) - only one c-clamp to remove the MAF housing which behind the airfilter housing and in front of the air intake... no need to remove the MAF sensor element itself from the housing, you remove the housing including the element and thoroughly spray clean the element inside the housing (several spray cleaning cycles best) . For cleaning no need to remove the element from the hosuing, but reove the housing from the intake to clean the element.

The (2) security torx screws, and removing the element from the housing itself only need to be dealt with if replacing the actual element.

The MB spec to Bosch was lowered (way lowered) like 1990+, and only recently brought back up to higher spec 2005+... so COMMON that MB MAF elements need to be cleaned to keep performance top notch... RARE on actual replacement, and if you have too replace the element itself which is cheaper than replacing the (element+housing) but make SURE the replacement element is genuine Bosch and not the Far East element knockoff (which does not last).

Keep the beat !