[BenzUberAlles]

Took the ML to autozone today (engine light). They diagnosed the problem to be the MAF sensor. In the last month the car was driven to Colorado to an elevation of 9K. I noticed the problem two weeks after the trip.

Question:

Is it possible to clean the MAF with alcohol? As anyone done this before with any success?

Thx,

 

[benzml320]

they actually make a MAF sensor cleaner sold at AutoZone or other car parts stores.
It's relatively cheap and is made for the job
Here's the DIY for it:
http://www.benzworld.org/forums/attachments/w163-m-class/94612d1155017380-mass-air-flow-maf-sensor-replacement-mass-air-flow-sensor-replacement.pdf

Here's the stuff:
http://www.crcindustries.com/auto/content/prod_detail.aspx?S=Y&PN=05110

 

[FAR888]

From what I understand cleaning the MAF sensor is always, at best, a temporary solution and it's better in the long-run, to buy a new one.

 

[Check Codes]

Cleaning with Alcohol means you have to touch it with a swab or something which many frown on.

The link above only shows replacing the assembly, but if you really want to clean it follow this DIY, which shows exactly how to do so: http://www.benzworld.org/forums/w210-e-class/1328069-maf-diy-pictorial-replacing-cleaning.html

So you let Autozone tell you the diagnosis instead of getting the codes, so if you want to accept their diagnosis then the odds are cleaning it will have a negligible effect unless you've been driving around with a damaged, missing or seriously-dirty air filter. Most of the time you just end up with a clean maf that has failed. If you plan on keeping the truck you're just forestalling the inevitable.

Last, DO NOT buy the replacement from ebay. Deal with a reputable vendor and buy GENUINE BOSCH. The cheap untested chinese replicas on ebay (marketed as bosch) will at best make your truck run worse, at worst they'll keep the light off and mask the fact that they are melting your cats or your O2 sensors. For genuine Bosch at the best price (with free shipping!), I'm not aware of anyone that beats autohausaz.com.

Take care and enjoy the ride,
Greg

 

[FAR888]

....For genuine Bosch at the best price (with free shipping!), I'm not aware of anyone that beats autohausaz.com....

Here's the link for AutohausAZ; I've already searched for you (even though I dont know what model or year truck you own) - I've guessed it's an ML320 pre-2002:

Your Parts Search Returned 0 Part(s)

$176 approx.

 

[jefferino]

I can beat them if you can use the one from my 2000 ML55 that I am parting out...let me know.

 

[Gene Horr]

From what I understand cleaning the MAF sensor is always, at best, a temporary solution and it's better in the long-run, to buy a new one.

Yep. The first time will last a couple of months if you are lucky but then the period starts decreasing rapidly. Just buy a new one. They are actually one of the cheapest I've found compared to other imports. Though this is offset by only lasting half as long....

Avoid the eBay cr*p/knockoffs. You aren't saving any money in the long term that way.

 

[BenzUberAlles]

Thanks for everyones help. Regarding Autozone, I saw the MAF code myself. I guess the problem is that after 10 years of K&N usage on many different cars, the ML MAF bit me in the keyster...

I have used AutoHaus AZ many times, good pricing. At 146K with minimal to no issues, unlike others that have owned these SUV's, I plan to drive it until the doors fly off. Driving it on ice / snow through Estes, CO just reaffirmed me that the ML minus it's short comings is a great off / on road vehicle.

 

[BenzUberAlles]

I forgot to mention there were two other codes that showed up. Throttle Position Sensor PO221 andd IAT Sensor PO110.

What are these???

 

[Witek_M]

IAT Intake Air Temperature is part of MAF.
TPS is pedal value sensor mounted on firewall with cable going to it from pedal.

To improve searchability of this forum powertrain codes should be stated as P zero XXX (P0110).

 

[ziska1999]

I replaced two MAF inserts in my 99 and 01 320's with the MAF insert from German Star who is a sponser of this site. The inserts are genuine Bosch replacement parts. Each insert cost $129.00 plus $6 for shipping. I had the insert the next day. Its a 10 minute swap out. I tried the MAF cleaner from CRC. It worked the first time for about 2-months, then it didnt fix the issue. Bite the bullet and get the insert. I havent had to look at mine for the last 2 years and going strong.

 

[Check Codes]

I forgot to mention there were two other codes that showed up. Throttle Position Sensor PO221 andd IAT Sensor PO110.

What are these???

Witek explained those for you, I just wanted to chime in that a failing MAF can indeed trigger many other codes...and if it does it's less likely that cleaning will help. If you got to 146K you got lots of extra life from it already.

Thus, I'd respectfully suggest you replace the MAF with a genuine Bosch and then clear the codes. Drive normally, then whether you have a CEL or not, recheck for pending codes. Those that don't return you can ignore.

If you do end up needing a TPS, I have one I ordered for my car and ended up not needing (I had the code but found the underlying issue before I received it), I didn't even open the shipping box it came in but I can't return it. PM if your TPS code returns without the MAF codes and I'll make you a deal.

Take care and enjoy the ride,
Greg

 

[Witek_M]

Don't worry about code P0221 until all others are resolved. That code is displayed on generic scanner and has nothing to do with TPS.

 

[FAR888]

I've subsequently learnt that cleaning of the MAF sensor can be more than a temporary solution, in a lot of cases, and that cleaning is only less likely to be a permanent fix IF original problems with the MAF sensor are ignored and the sensor subsequently becomes out of range.

So cleaning, rather than purchase of a new MAF, can be an option in certain circumstances.

 

[oreif]

beating the 'replace' drum again, but just did mine with only 93k on it last month. got from autohausaz.com & zero complaints as it is original. to echo greg's point, she kept spitting out p0140 but due the 'great one's' prior posts I chose to ignore it for a time & clear for a while. checked my 2ndary air injection points and whaala. not a single code or pending in almost 2.5 weeks. maf's & tps are among the buggiest points of this thing-replace, keep peace of mind, & drive on.

 

[LT1]

I had these same two codes pop on my '01 ml 320. I cleaned the MAF insert and replaced. The CEL went out for a few months. It recently came back with the same two codes. I bought one of those cheap inserts through amazon and installed. My car misfired, hesitated and wouldn't take anything but light throttle without bogging down. I put my old 'dirty' MAF back in and car runs as normal. Do I need to reset the car (take battery terminal off or something) or is this cheapo part just a POS?

 

[Check Codes]

I had these same two codes pop on my '01 ml 320. I cleaned the MAF insert and replaced. The CEL went out for a few months. It recently came back with the same two codes. I bought one of those cheap inserts through amazon and installed. My car misfired, hesitated and wouldn't take anything but light throttle without bogging down. I put my old 'dirty' MAF back in and car runs as normal. Do I need to reset the car (take battery terminal off or something) or is this cheapo part just a POS?

If you'd searched the site first you'd have found horror story after horror story about chinese knockoff maf inserts. At least amazon will take it back. Order a new assembly from autohausaz.com, divided over the life of a maf you're spending what, $4 a year for the genuine article over the knockoff?

Take care and enjoy the ride,
Greg

 

[LT1]

If you'd searched the site first you'd have found horror story after horror story about chinese knockoff maf inserts. At least amazon will take it back. Order a new assembly from autohausaz.com, divided over the life of a maf you're spending what, $4 a year for the genuine article over the knockoff?

Take care and enjoy the ride,
Greg

I agree, and I shoulda sold out my 401k in Oct of '07 but I didnt...:crybaby2: Anyway, autohaus shows the whole assembly (sensor and pipe). Don't I just need the the sensor insert? Where's the best place to buy? Thanks for the help.

 

[43sqd]

I agree, and I shoulda sold out my 401k in Oct of '07 but I didnt...:crybaby2: Anyway, autohaus shows the whole assembly (sensor and pipe). Don't I just need the the sensor insert? Where's the best place to buy? Thanks for the help.

You don't seem to understand. If you buy just an insert it is a knockoff. A true MAF sensor is Bosch made and comes with the tube. Autohaus sells the original.

 

[Witek_M]

You don't seem to understand. If you buy just an insert it is a knockoff. A true MAF sensor is Bosch made and comes with the tube. Autohaus sells the original.

Another nice thing about original MAF is that it comes with caps that should be saved and later used during repair jobs. Anytime MAF or upper part of air box is removed for other repair jobs like EGR or spark plugs they need to be capped or wrapped in clean plastic bag to prevent contamination. Silicone based spray lubricants are killers of both MAF and oxygen sensors.