StapleGun

This website details how to clean MAF, even though the vehicle portrayed is a BMW, I believe the MAF MB used in Benzes is the same. I will be attempting cleaning the MAF on my vehicle employing this procedure this evening and see what the result is. I have ordered a new part and am awaiting shipment but I'll clean the MAF in the interim. I'll let you guys know how it goes.

A little backgrounder... I purchased a 1998 C43 and the CEL has illuminated. I put an ODBII scanner/reader and downloaded codes P0170 and P0173 - fuel trim - left and right banks, respectively.

http://www.louv.tv/cars/m5/MAF/

trbo2nr

Those codes sound too familiar. Yep, let us know how the cleaning works out.
I've never tried cleaning it. Maybe one day....it's bound to happen again.

hangup

yes, this looks like the one i've got in my car at least from the outside.
thanks a lot for the link! one day i might really need it
probably even this year as i just replaced the air filters and the old ones looked really dirty and the car is almost 6 years old now . . . i doubt MAF was ever cleaned.

i had to clean the MAF sensor on an old taurus a few years ago, it was a bit more difficult because the sensor wire was easy to break and the security screwes were not torx . . . they had a pin in the middle! i had to drill them out.
so this looks like a walk in the park!

once again, thanks a lot for the link!!!

hangup

oh wait these screwes also have the pin in the middle
i wonder if mine do . . . i'll have to get the right torxdriver.

StapleGun

Yes, the C43 has the security torx screws. Griot's has the necessary tools, two versions (my advice - get the Wiha German one versus the cheap tamper-proof bit set). See the weblink below.



This clean-up for the MAF is cake, very easy to do. I can say that after a short test drive, it appears that it works. No CEL and the car shifts way better with no lag and a smoother transition between shifts.

If anybody has any questions regarding the clean-up procedure please feel free to drop me a line. [cohibas4u@NOSPAMyahoo.com - remove NOSPAM]

I dipped the grid into the Simple Green for half an hour and there was quite a bit of debris at the bottom of the bowl.

The portion that fits within the MAF housing required some cleaning. The metal probe that is subject to the airstream immediately following the grid was black, this black debris was easily removed with a Q-tip.

All rubber gaskets were cleaned and lubed with petroleum jelly prior to assembly.



http://www.griotsgarage.com/catalog....L1_2000&Page=2

Co 55 AMG

Great Info! Thanks!

MarcusF

What brand and model OBDII scanner are you using? I'm in the market for one. Thanks

trbo2nr

I use the AutoEnginuity one that runs on my Palm and my laptop. I think the
site is autoenginuity.com

I keep the Palm PDA in the car for emergency diagnostics and the laptop I connect only if I want to drive and do some logging (to hard drive).

linuxfoo

Kragen has a decent one for $99 i think the brand was novia or somthing like that, its an ODBII scanner, it will read and also clear codes.

StapleGun

Go to www.iequus.com the 3100 model will read and clear codes.
I paid about $130 for it. Do a search, I think I got it from autobarn..there are others who have it too.

MarcusF

Thanks guys.

StapleGun

The MAF clean-up I posted was a temporary fix - the CEL did not illuminate for approximately 100 miles, give or take. I cleared the codes (using the 3100 iequus OBDII scanner), cleaned the grid and air mass probe and, as stated previously, it worked for approximately 100 or so miles....and voila! The CEL, makes an encore appearance.

So, I replaced the MAF...it was on order when I posted the fix. Figured it was good 411 for everybody, especially the security bits info.

I purchased the MAF on ebay for $203 inclusive of shipping and car runs like a top, finally.

linuxfoo

hey staple, i took your advice and just cleaned mines. although my car never displayed CEL nor any fault codes, i kinda knew mines was on its way out. the only thing that i did differently was that i did not use simple green. although simple green is an excellent degreaser, i knew it kinda leaves a residue so i opted to not use it, just pure alcohol and some electronic contact cleaner.

man what a difference it made after cleaning. lets just see how long it lasts.

StapleGun

Hey Linux,
I probably should have done the same. An electrical cleaner of some sort and alcohol is the way to go. I had ordered the MAF already, then I found the aforementioned website and figured heck - I have nothing to lose. Let me know how it holds up. Thanks in advance to everyone on this forum, the collective knowledge available is worth millions, it has been extremely helpful to me.

One final note, even though I have not had any troubles with tranny. I have performed a pre-emptive strike (i.e. flush and fill) to hopefully preclude any troubles. To have mercedes state that this transmission should be fine without a change in 100K is beyond assine. Happy driving to all!!

hangup

Hey Linux you're one lucky guy
I was in the same shoes as you but i did use the geen stuff. Well, now CEL light comes on and idle is rough.
at high RPMs it seems OK, but idle is no good.
I did try the reset . . . same thing.
I'm going to have to reopen the thing tonight and try to clear it again
Should not have touched the thing in the first place . . . but i already knew that
Staple, who did you get your new MAF from? Is it a good source? Do they have more? I may be in the market for one now.

StapleGun

Hangup,
The seller is msg2002 and here's the link for one for sale now. Price is $203.95 Buy it Now and it's the price I paid, shipping included. He shipped very fast and is a straight up seller - I had no problems whatsoever. MAF arrived in yellow Bosch box and is brand-new. Let me know how it goes.

http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW

linuxfoo

yo hangup, try to take it out again and clean it with alcohol, pay special attention to the metal flat plate inside the sensor, clean that good with alcohol, you can even try soaking it a bit to get it all clean and use some canned air to blow it dry then install. you really aint got nothing to lose at this point

hangup

yep Linux, tried that all night last night
the fact is, MAF is screwed.
so i've ordered the new one and now waiting.
won't be driving the amg for a few days, not a biggie. got taught a good lesson though i'm glad i resisted the temptation of flushing the tranny ))
these temptations can get to you sometimes, especially on a long weekend with too much free time on your hands.
usually i don't have any so i have nothing to worry about until the 4th of july weekend i guess ))

once i was 100% sure the MAF is screwed i opened it up (no, REALLY opened it up) to understand what happened.
i understand perfectly now
these MAFs are not to be screwed with. from the outside it *looks* a lot more rugged than the taurus sensor i cleaned successfully a few years ago, but in reality it is much, much less rugged.
if you hold it upright, the metal plate on the bottom is pretty much to cool it down i think. the real thing is at the top where the turning air passage is.
the element pretty much looks like a film resistor, only it has no case. so from the side it looks like a piece of aluminium or something, but in reality it has two elements: the aluminium base and a delicate piece of material rectangular shaped with a hole in the middle.
so, don't even THINK about blowing compressed air in there!
i actually had a can and just for kicks (since it was alreay gone) i blew at it just a little bit. part of the film came off pretty much right away!
so, very delicate, do not blow, do not pour anything in, do not shake, especially while in fluid.

and the bottom line is, you likely won't be able to clean it. i think mine developed a slight discolaration of some sorf due to probably liquid left on it while it was turned on and it must have gotten hot and burned.
i think removing the liquid from there even if it's alcohol is pretty much impossible, since even a slight blow can destroy the sensor film element.
the liquid can easily get trapped in between the film and aluminum base and it could take a long time to evaporate. i waited two days and the MAF still got screwed up.

so if anyone is still reading this, let this be a warning to everybody who iis about to try this on a still working sensor . . . don't. unless you've got 200 bucks jumping out of your wallet and biting your behind ))

also, i read a lot about K&N filters with overoiling, etc. some folks suggested that while oil can get there it's not a big deal to clean the sensor if that happens . . . i figured i'll stick to mann papaer filters from now on

StapleGun

Thanks for the info hangup! I only posted this for those like me that had to replace the MAF and had nothing to lose.

The car I purchased has the K&N filters and I would agree, that if they are over-oiled the oil may cause problems with the MAF. When I cleaned the MAF, there was quite a bit of sediment on the bottom of the bowl I used and the probe facing the incoming air was blackened. As far as the air filters, I believe OEM is the way to go.

So there's my two cents, thanks for the follow up on "opening up" the housing and probe itself.

ProjectC55

Now this is excellent!!

hangup

Staple, thanks for the pointer to that seller, got my MAF today. Paid a bit extra for overnight shipping, but it was worth it, i may need the car this weekend.
Installed, reset the car, testdrove, no problems.

ProjectC55

New MAF usually makes a big difference!

Teck

True I had to change mine again after 15k miles! Yesterday I missed some power so I conected my babdy to the Star Diagnosis this afternoon and it said that the MAF is broken again!

ProjectC55

Wow! Really! I think I'm going to purchase another as a spare.There is so much heat in back of these intake mani's as well and I'm wondering if this also has a definite effect on the longevity of the MAF.

StapleGun

Hey Hangup, Glad to be of help..he shipped fast. I'm almost tempted to buy a spare and store away. I just ordered new factory air filter filters, I'm yanking the K&N's off. After inspecting the old MAF, I can see how oil would fly into it and damage.