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How to clean the (MAF) Mass Air Flow Sensor?

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Old 02-28-2004, 01:56 PM
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How to clean the (MAF) Mass Air Flow Sensor?

I managed to get mine out from the ML...was a piece of cake...question is how does one clean it - meaning what material/liquid/alcohol should be used and what procedure to follow - all that? And how to test it if the cleaning helped?

Any advice?

PS I wanted to post the picture of my MAF along with this message, but attach image limits me to to just 1 byte? Is this is a bug in the site, or am I missing something here..

Last edited by mihir_d; 02-28-2004 at 01:58 PM.
Old 02-28-2004, 03:54 PM
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Its very delicate. Should not be cleaned or fooled around with, odds are you will render it inoperative. It is a consumable
Old 02-28-2004, 04:14 PM
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a car that can't do the throttle reset.
mihir_d...dont mess with it. it isnt something that you need to clean... it is either working or not. why...are you getting a check engine light?
Old 02-28-2004, 06:13 PM
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Symptoms I experienced when MAF was bad:

CEL staying on.
Lack of Power, Hesitation.
Sometimes didn't want to idle after first start.

We were told by the MB dealer, MAF was the problem.

I took it off to see if it could be repaired. I didn't want to use chemical on it which could make it worse. Lightly wiped it with a tissue, no dirt!

I even tried running it without the air filter in place to see if a restricted air intake was causing the problem.
It was only an accidental thought, that I decided to unplug the electrical connector and run it that way. Now, I had Power back and it ran good.

I would suggest not messing with it......unless you absolutely sure. You may then end up paying for it!
Old 02-28-2004, 06:47 PM
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How can you clean it with a soft tissue?

Forget a tissue, except for a look at the wire with a flash light, I can't even get to it...it is buried so deep inside the casing.

I really wish I could post the picture..can anyone explain, why I can't attach jpegs anymore...I keep getting the error, your attachement is greater than 1 byte.

I haven't got the Check Engine Light yet, but my mileage has dropped significantly and I took it to the dealership for inspection...they said that was the first sign of the MAF going bad...also they said, there was voltage on the sensor which kind of proves beyond doubt that that is the culprit.

They are recommending replacing it...I thought, might as well try some DIY things and see if any of that helps...
Old 02-28-2004, 06:52 PM
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Re: How to clean the (MAF) Mass Air Flow Sensor?

Originally posted by mihir_d

Any advice?
You can buy a new one here http://www.importeccatalog.com/


PART NUMBER SEARCH RESULTS WITH PRICES

Vehicle 2000 Mercedes Benz ML 430
Part: Air Mass Meter

Note:


Product Brand Availability Retail Our Price
B3130-114622 Air Mass Meter Bosch IN STOCK $280.00 $276.20

B3130-115776 Air Mass Meter IN STOCK $280.00 $272.93
Old 02-29-2004, 09:55 PM
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I cleaned my MAF and the mileage is back up to normal 17-18 mpg in city...

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/kno...x_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; 02-29-2004 at 10:05 PM.
Old 03-01-2004, 06:09 PM
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mihir_d That's good news!

Guess I didn't know what I was talking about. Glad you found a way that will save us all some money in the future.
Old 03-01-2004, 07:40 PM
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I am amazed that it still works!! You must have surgeons hands!! It won't work beyond the short term though. The most common cause for MAF failure but not the only cause is running with an aftermarket/"performance" air filter or no air filter at all.
Old 03-01-2004, 09:58 PM
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Yes it was an extremely tricky job to do...

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; 03-01-2004 at 10:05 PM.
Old 03-02-2004, 02:00 AM
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Here's a complete picture of the tools involved...

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; 03-02-2004 at 12:43 PM.
Old 12-02-2010, 10:07 AM
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Where is this sensor located in the ML 270 CDI?
Old 12-02-2010, 02:28 PM
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Originally Posted by Heinrich
Where is this sensor located in the ML 270 CDI?
I believe the diesels don't have mass air sensors.
Old 12-02-2010, 02:34 PM
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CRC also makes a spray specifically designed for cleaning MAF sensors... although the electrical cleaner works fine from my experience.
Old 03-31-2011, 07:53 PM
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Thats the way the Mercedes Bends!!

Originally Posted by mihir_d
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/kno...x_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...

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