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1999 e300 Tubo Diesel
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Discussion Starter #1
Hi,

Before I started to clean my MAF. My check engine light was OFF.

I removed the MAF, used MAF cleaner. Let dry about two hours. Went for a drive and the CHECK ENGINE light came on.

Any thoughts or suggestions as to what might have happened? And how to turn off the light.

thanks

Wayne
 

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1996 210.020
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Hello Wayne and welcome to the forum. Please take a moment to complete your user profile, available via the "User CP" link. Your location is especially important for questions like this.
 

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'01-E320 & 02-ST2
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Hi, Wayne. If I can digress a bit first, may I respectfully suggest that you remove your phone number from your sig? Aside from the personal/security issues, there are internet bots that do nothing but crawl the web culling personal info like phone numbers and email addresses and you end up on lots and lots of lists. Totally up to you of course, just wanted to make you aware of that.

Turning to the reason for your post, I have a few ideas that can be crystalized with some questions.
First, what prompted you to clean it?
Second, exactly what steps did you take to clean it and what products did you use in your endeavor?
Third, how quickly after restarting did the light come on?
Fourth, how is the car running compared to how it was before?
Fifth, have you checked codes? Have you cleared codes?
Sixth, how many miles on the car?
Post back up with the above and we can figure it out.

Take care and enjoy the ride,
Greg
 

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1999 e300 Tubo Diesel
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Discussion Starter #4 (Edited)
Thanks for your help Matt & Greg

I have implemented your suggestions.

About the car and me.

I'm an xBMW tech now programmer. The car is a 1999 e300 165k miles. Runs very well.

I'm trying to get the max mpg just to see what it will do. The best hwy is 31MPG. Around town about 17MPG.

I think the MPG can go up to 35MPG. Last weekend I replaced the O-ring at the turbo boost pipe to the EGR valve at the intake manifold. It was leaking and making the area wet. I clean it up and the car has been running well for the past week. I remembered a thread about cleaning the MAF. I unscrewed it with the security torx and it was dirty, light wet look nothing alarming like a blow or leaking turbo. I cleaned it with the CRC brand MAF cleander. I saw a nice thread with some photo, I made sure as to touch any of it with the tip of the nozzle. used 3/4 of the can on it.. its totally clean. OK. here is where I thought maybe I messed something up.

Just under the EGR valve about six inch's is a sensor on the turbo boost pipe it has two leads, plastic is round and black. I cleaned “sprayed with the MAF cleaner, using up the can” to knock away some of the old residue from the previous weekends repair of the turbo boost pipe which required the removal of the intake manifold I got it shiny and I also squirted the sensor.

NEXT.

it started well like normal, did not notice a check engine. I punched it at my intersection, and it took off like normal “torquey and fun” then about 1 mile from home I noticed the check engine light.

Driving HOME with check engine light on.

I live at the top of a step hill, as I preceded up the hill the car has significantly less power. it felt like the kick down was not working with the transmission “which I love” I was definitely giving it lots of pedal.

PARKED the car.

Inspected the MAF, it looked fine and the connection pins were all in place and firmly seated. Next it removed the terminal on the turbo boost sensor. It was OILY. I thought humm, I must have been soaked from the MAF, but it had two hours to evaporate before I drove it. It was oily and I cleaned the terminal with the MAF cleaner (had some left), and removed the sensor from the turbo boost pipe. cleaned it with MAF, put some oil on the O’ring and installed.

Drove the car again, and the power is reduced probably by 20% (originally I put 40%) it feels like its driving in the wrong gear and pedal movement does not seem to change anything, NOTE: I never did a kick down throttle.

I decided to buy OBD II Scanner, it should be here by Friday.
(CAN OBD II CODE SCANNER WITH TEXT DISPLAY 94217-2VGA 89.99)

Thanks for the help and feedback.
 

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E320/E250 Bluetec Ford F350 6.7l
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Maybe he put the phone number on purpose? ;)
I agree with Greg's questions. You had to have a reason to clean the MAF in the first place. If you read the forum you'll find out that cleaning the MAF is having very small success ratio. It might help if you had damaged filter and dirt stuck to the sensor, but I had 0 success ratio on 4 MAF cleaning.
BTW Wayne. My experience shows that Bay Area traffic is the heavy mpg killer. Not only you drive at high speeds, but have constant braking/acceleration issue. Our 300dt made 36 mpg in other states, where my wife kept it at steady 70 mph, but getting closer to 20 mpg on mostly freeway driving in Bay Area is normal occurrence. The same always was with other cars. Even famous VW tdi, that makes 50 mpg for people in other states, averaged 32 mpg for me.
 

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2000 MB
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Maybe the MAF is on its way out. It just so happened that it gave you that reading after you cleaned it.
Try changing to a new one and if the same problem, at least you know you have a new maf in there. She's 9 years old already.
 

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Hi, Wayne.

With all due respect to 430sport I would not start changing ANYTHING until you get codes read. There are dozens of sensors in the 210 that can trigger a CEL and that's why you have codes so you don't replace parts needlessly. MAFs don't fail merely because of age and can last the life of the car. Moreover, even if you disconnect the MAF you would not notice a significant drop in power and certainly not of the magnitude you have estimated. Including the fact that you described a process that would not damage it, I think it highly unlikely that your codes will be for a MAF.

If you don't want to wait until Friday Autozone will read codes for free, or if you want to drive just a bit south I'll read them for you. (Then Kajtek1 can interpret and diagnose them in the TD context. ;))
In the meantime unplug the other socket you referenced and blow out both ends with compressed or canned air until you are sure it is dry, clean the connectors of any dried/accumulated goo, plug it back in and go for a gentle drive. And keep your fingers crossed.

Take care and enjoy the ride,
Greg
 

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1999 e300 Tubo Diesel
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Discussion Starter #8
Good Feedback, I'm waiting to get the OBD II reader, to find out what the codes are. I'll post the data when I get it.
 

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Discussion Starter #9
You had to have a reason to clean the MAF in the first place.
I'm trying to learn what my car's MAX MPG will be. I thought the city MPG was very low and all signs pointed to the MAF.
 

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1999 e300 Tubo Diesel
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Discussion Starter #10
I got my reader today and it say's the MAF is causing the Check engine light "CIL". Wow, I cleaned a working MAF and it killed it, has this happened before?
 

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E320/E250 Bluetec Ford F350 6.7l
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MAF to my knowledge doesn't trigger its own codes. On gasoline engine you have misfires and several codes leads to conclusion of MAF failure. How on diesel it displayed MAF failure? What is the code number?
 

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1999 e300 Tubo Diesel
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Discussion Starter #12 (Edited)
I erased the code, but It was P0100. My reader will tell you what it is (air flow meter) including the code.

FYI, any item on the emissions label under your hood will throw the check engine light, thats its job. (former California smog tech)
 

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2014 E350 4Matic sedan, 68K miles (purchased Jan 2017)
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hey wayne, what was the exact code you got from the reader? sometimes, for example, a P0171 code could be either the MAF or the o2 sensor; i know that's the case w/ the lexus we own at least.

edit - i see you posted the code now
 

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Discussion Starter #14 (Edited)
photo of error code

Here is a photo of the error code and description.

I have a MAF arriving tomorrow.

I think this is the first case of cleaning a MAF that killed it.
 

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Here is a photo of the error code and description.

I have a MAF arriving tomorrow.

I think this is the first case of cleaning a MAF that killed it.
I seriously doubt your cleaning killed it unless there is something you're not telling us :rolleyes: ...or something that happened to it while it was out of the car of which you're also not aware. If cleaning killed it it would happen much more frequently...plus this would also be the first time a MAF was specified for that code.

Your P0100 code is not the MB code that specifies the MAF itself. MB code is for "Fuel Trim", P0170 and P0173. From a casual search on the site your P0100 code suggests the MAF CIRCUIT (as your display suggests) -- not the sensor itself. (That said, I hope I'm wrong otherwise you just dumped lots of money.)

Did you try de-gunking the other connector you mentioned? Did you confirm wires okay, connection good and clean, etc.
 

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2014 E350 4Matic sedan, 68K miles (purchased Jan 2017)
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He DID use 3/4 of the can on the thing, who knows, maybe drenching it like that did kill it? Or maybe the timing was just really bad and cleaning it didn't work but it died shortly after? Let's discount that theory for a second; it's still possible a new MAF could fix the issue. Maybe it works differently in different makes, but on my wife's Lexus, our code was P0171, not -0 or -3. I replaced w/ a new MAFS after cleaning it made the error go away for a few months, and then the same code came back. Haven't had any issues since.
 

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If I could trouble you to test a recovery method. If you don't mind, I am curious as to whether the malfunctioning MAF sensor could fixed. If would be nice if we can undo the CRC cleaner effects. The following procedure is what I have in mind.

(1) Submerge the bad MAF insert unit into a solution of SIMPLE GREEN for an hour or so. You may want to move the MAF around from time to time, but it is probably not that important.

(2) Rinse the MAF insert and submerge it in clean water overnight.

(3) Let it air dry for about a week.

Thanks.
 

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He DID use 3/4 of the can on the thing, who knows, maybe drenching it like that did kill it? Or maybe the timing was just really bad and cleaning it didn't work but it died shortly after? Let's discount that theory for a second; it's still possible a new MAF could fix the issue. Maybe it works differently in different makes, but on my wife's Lexus, our code was P0171, not -0 or -3. I replaced w/ a new MAFS after cleaning it made the error go away for a few months, and then the same code came back. Haven't had any issues since.
Hey, FJ. P codes are to some extent manufacturer-specific. If his reader had thrown out the 170/173 codes I'd agree that the timing was bad, etc. But the P0100 code reaches to the circuit, not the sensor (as Kajtek1 points out there isn't actually a code for the MAF, it's really a question of other codes, classically the pair of fuel trim codes for modern MB). On the other hand, this is the oiler, so it may be a bit different, too. My concern is still that he hosed down that other connection (not clear whether he disconnected it, cleaned, let it dry, degunked, etc. before re-energizing the circuit) and that could have affected things (see quoted excerpts below describing his efforts). Also, you can disconnect your MAF and it won't seriously affect engine performance and surely not to the level he describes. I think the other cleaning attempt is going to be the root cause; if you goof up the turbo circuitry you're definitely going to have performance issues. Again, I hope I'm wrong, popping in a MAF is much easier than chasing gremlins, but ...

Who knows, it may turn out that the other connection he cleaned was still wet enough to short and it blew an odd fuse somewhere, wouldn't necessarily throw a code unless it's emission related, then properly cleaning the connection and replacing the fuse and he's back in business (with a MAF to sell). But all of that is pure conjecture. As has been pointed out before, diagnosing over a forum is -- shall we say -- fairly difficult. ;)

Just under the EGR valve about six inchs is a sensor on the turbo boost pipe it has two leads, plastic is round and black. I cleaned “sprayed with the MAF cleaner, using up the can” to knock away some of the old residue from the pervious weekends repair of the turbo boost pipe which required the removal of the intake manifold I got it shiny and I also squirted the sensor. *** Inspected the MAF, it looked fine and the connection pins were all in place and firmly seated. Next it removed the terminal on the turbo boost sensor. It was OILY. I thought humm, I must have been soaked from the MAF, but it had two hours to evaporate before I drove it. It was oily and I cleaned the terminal with the MAF cleaner (had some left), and removed the sensor from the turbo boost pipe. cleaned it with MAF, put some oil on the O’ring and installed.
 

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1999 e300 Tubo Diesel
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Discussion Starter #19 (Edited)
Thanks for the feedback.

I did through clean of the air sensor & wires in the tuboboost pipe. so I don't think its that.

(popping in a MAF is much easier than chasing gremlins)
I agree and my MAF is arriving tomorrow.

about 1 minute after the original clean, through the CIL. So I suspect its the MAF.

-------------- found this about the codes ------------
OBD-II Trouble Code: P0100 Mass Air Flow (MAF) Circuit Malfunction

P0100 OBD-II Trouble Code
Technical Description

Mass Air Flow (MAF) Circuit Malfunction
What does that mean?

Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit.
Symptoms

You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

I do have Sluggishness and decreased power.
 

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In relation to this topic, my MPG on freeway usage is just about 22 - 23 MPG. Compared to 35 MPG of Wayne. Could this be an MAF problem?
I don't drive aggressively and so I can't say if its sluggish or has less power.
Wayne, please do come back with result when you have done replacement. THAnks.
 
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