S-Class (W220) 1999-2006: S 320 CDI, S 320, S430, S 500, S 600

MAF replacement instructions please (Oxygen?)

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Old 11-10-2006, 09:58 PM
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MAF replacement instructions please (Oxygen?)

Hi,

Can somebody please post detailed instructions on replacing/cleaning the MAF sensor, with some diagrams, if possible? I bought some CRC MAF sensor cleaner, would like to tackle the job tomorrow, but not sure how to even take the cover off! Also, what tools are required? Any help is appreciated.

Thanks in advance.

-esprit ('03 s500 43k miles)
Old 11-12-2006, 10:12 AM
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done, but issue persists

I managed to eventually find this thread which helped me do the job. Thanks.

The funny thing is that I forgot to plug the MAF back up after cleaning it and the car began hesitating for a moment when I depressed the gas pedal, until I realized what I had done. Shouldn't the CEL have come on with he MAF unplugged?

Anyway, cleaning the MAF (which appeared to be quite clean already) did not take care of the idle issue I have been having; when in park, the car will rock a little every few seconds, seems irregular. When in D (but idle) I think I still feel it, but barely. Engine mounts were replaced by the dealer to no avail. According to the dealer it's all in my head and the car is supposed to do that in park since the engine 'floats' and is not locked down by the transmission. Is this true? Should I be expecting the car to shake irregularly every few seconds? The dealer said there were no error codes or events in memory and raised the idle RPMs a little to help the issue. They showed me the STAR computer screen and a few of the menus all seemed normal, the idle RPMs were clearly fluctuating a little (in the 800-900s), which the tech explained was normal.

The shaking is not strong by any means, but noticeable. Any ideas?


Thanks,
esprit
Old 11-12-2006, 02:59 PM
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give her a shot of redex
Old 11-12-2006, 04:45 PM
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AMG E55, Stage 1, Strait Pipe from Primary Cats
Originally Posted by esprit
I managed to eventually find this thread which helped me do the job. Thanks.

The funny thing is that I forgot to plug the MAF back up after cleaning it and the car began hesitating for a moment when I depressed the gas pedal, until I realized what I had done. Shouldn't the CEL have come on with he MAF unplugged?

Anyway, cleaning the MAF (which appeared to be quite clean already) did not take care of the idle issue I have been having; when in park, the car will rock a little every few seconds, seems irregular. When in D (but idle) I think I still feel it, but barely. Engine mounts were replaced by the dealer to no avail. According to the dealer it's all in my head and the car is supposed to do that in park since the engine 'floats' and is not locked down by the transmission. Is this true? Should I be expecting the car to shake irregularly every few seconds? The dealer said there were no error codes or events in memory and raised the idle RPMs a little to help the issue. They showed me the STAR computer screen and a few of the menus all seemed normal, the idle RPMs were clearly fluctuating a little (in the 800-900s), which the tech explained was normal.

The shaking is not strong by any means, but noticeable. Any ideas?


Thanks,
esprit
When were the plugs changed last ? If you have more than 50k with the original plugs then change them. I changed mine at 50k and they looked like hell.
Old 11-13-2006, 11:26 AM
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I did...

Originally Posted by mioba
give her a shot of redex
Hi mioba,

That was my first thought as well. Treated her with a bottle of complete fuel system cleaner once and with two bottles another time, but nothing changed.

Thanks,
esprit
Old 11-13-2006, 11:33 AM
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Originally Posted by benznodubz
When were the plugs changed last ? If you have more than 50k with the original plugs then change them. I changed mine at 50k and they looked like hell.

43k miles. I have an appointment for an oil change at the dealership today, I am thinking about asking them to change the spark plugs as well. I plan on driving the car for at least 50k more miles, so I figure that's an expense I will have to incur anyway. BTW, is this a job that most independent shops should be able to tackle as well?

The vibration is driving me nuts! This is how I bought the car (didn't know it at the time) and it has been 2k miles since. It doesn't seem to be getting worse, at least not quickly enough for me to notice.

Regards,
esprit
Old 11-13-2006, 12:25 PM
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AMG E55, Stage 1, Strait Pipe from Primary Cats
Originally Posted by esprit
43k miles. I have an appointment for an oil change at the dealership today, I am thinking about asking them to change the spark plugs as well. I plan on driving the car for at least 50k more miles, so I figure that's an expense I will have to incur anyway. BTW, is this a job that most independent shops should be able to tackle as well?

The vibration is driving me nuts! This is how I bought the car (didn't know it at the time) and it has been 2k miles since. It doesn't seem to be getting worse, at least not quickly enough for me to notice.

Regards,
esprit
Find an independent Benz shop and have them do the plugs and oil, 50 % less in price etc. the dealer is good only if your car is under warranty, otherwise they are a joke.

ps.Where are you located ?
Old 11-13-2006, 05:41 PM
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Originally Posted by benznodubz
Find an independent Benz shop and have them do the plugs and oil, 50 % less in price etc. the dealer is good only if your car is under warranty, otherwise they are a joke.

ps.Where are you located ?
Tampa Bay, Florida.

I just got back from Lokey Mercedes. Got the oil changed ($79.95) and managed to get two of the techs to get inside the car and feel the vibration. They got inside and brainstormed. Asked me what type of gas I was putting in, if engine mounts had been replaced, if I had used any fuel system cleaners, which I had. I heard words like 'injectors', 'carbon build-up', EKG (or something similar...), 'pressure pump'.

They want to start with the engine treatment since it seems that the valves are not working evenly ($150). They did not believe that this was caused by the spark plugs. According to the service coordinator, it's not a good idea for them to take too long to try to diagnose the issue, because my aftermarket warranty (Mercury Insurance) may not pay for a lengthy diagnosis.

I will go there at 9am tomorrow and then post the results here.

Regards,
esprit
'03 S500, 43k miles
Old 11-14-2006, 11:21 AM
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Did the injector system cleaning today. Spent $150 but don't see a difference, car still shakes at itle. I will go ahead and try to replace the spark plugs and cables myself, following the instructions posted in these excellent threads:

https://mbworld.org/forums/c36-amg-c43-amg-w202/142196-changing-c43-sparkplugs.html
https://mbworld.org/forums/showthrea...ighlight=spark

Would a faulty EGR valve cause shaking at idle?

Thanks,
esprit
Old 11-14-2006, 11:32 AM
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I may have a same problem. The car has been doing the same thing as your car since 30~40k miles. As I am getting my car back on today, I will try replacing the MAF on the car since I have the parts. (currently 60k mi)

IMO, the "rocking" symptoms could be caused by the following:
1. Engine Mount (small chance of cause because you already have replaced it)
2. Transmission Mount - I had to replace one on my S350 (in Asia) for the same symptom, and the vibration on the car disappeared. THe most likely parts that have to be replaced!! This would be the best try.
3. Injectors - Irregular fuel injection could result in a unstable idle.
4. Spark Plugs- Non-consistent spark strength / etc.

Hope this could help you. I might replace the engine mounts when I do the transmission fluid change.
Old 11-14-2006, 11:35 AM
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Could be EGR valve, but if my symptom is same as yours, it would most likely be transmssion mounts, your car and my car has too little mileage for EGR valve.
Old 11-14-2006, 12:12 PM
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Thanks for the reply. The unstable idle I am experiencing is most pronounced when the car is in park. With that in mind, is it probable that it is caused by bad transmission mounts? Isn't the transmission disengaged while in park? Also, in a very quiet environment I can hear the sound of the engine change slightly when it shakes. At night, I can also see a very subtle change in the intensity of the dome lights. I connected a volt meter to the cigarette lighter plug, but the fluctuation is very slight, less than when a window is being closed for example.

Thanks,
esprit

Originally Posted by Darknessph
I may have a same problem. The car has been doing the same thing as your car since 30~40k miles. As I am getting my car back on today, I will try replacing the MAF on the car since I have the parts. (currently 60k mi)

IMO, the "rocking" symptoms could be caused by the following:
1. Engine Mount (small chance of cause because you already have replaced it)
2. Transmission Mount - I had to replace one on my S350 (in Asia) for the same symptom, and the vibration on the car disappeared. THe most likely parts that have to be replaced!! This would be the best try.
3. Injectors - Irregular fuel injection could result in a unstable idle.
4. Spark Plugs- Non-consistent spark strength / etc.

Hope this could help you. I might replace the engine mounts when I do the transmission fluid change.
Old 11-14-2006, 01:52 PM
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Yeah, that is what I have thought. The transmission is disengaged in a "park" position. Espirit, try putting the car into reverse and see if you still get that "rock". This method was used for determining transmssion mount failure on the S350 I have in Asia.(told to do so my the mechanic)
Old 11-16-2006, 03:57 PM
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No, no rocking while in reverse. It seems that the "rocking" is coming from the engine. In a quiet environment I can hear the sound of the engine change a little, as if the RPMs are dropping (the tachometer does not change). The rocking is most expressed while the car is in Park. It is by no means hard, I have to turn the music off (so there is no base) to feel it properly. But once you do notice it, it's pretty clear and defined. In drive or reverse, when the engine is "held down" by the transmission, it is practically unnoticeable, I only notice it because I look for it.

44k miles now, no codes, MAF has been cleaned, injection system has been cleaned, engine mounts replaced.

Any suggestions as to the next step are appreciated.

Thanks,
esprit

Originally Posted by Darknessph
Yeah, that is what I have thought. The transmission is disengaged in a "park" position. Espirit, try putting the car into reverse and see if you still get that "rock". This method was used for determining transmssion mount failure on the S350 I have in Asia.(told to do so my the mechanic)
Old 11-27-2006, 10:07 PM
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Hey Esprit,

I've been noticing the same on my 01 S500. I don't think it's the engine mount because I open the hood and put my hand on the engine and can feel the vibration or rather the engine sputtering every couple of seconds. In the cabin, it's definitely felt and I sat in my mother-in-law's S430 and notice that it was vibration free. This definitely bothers me and I have been searching the forums for the last 30 min to see what people have said. Seems like you have tried everything. Have you changed spark plugs yet? I've been having this problem for the last 2 years but now I want to find a solution. Let me know what you find. Thanks.

Phil
Old 11-27-2006, 10:25 PM
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CLS 63 S AMG , s500,clk550
Originally Posted by mioba
give her a shot of redex
what is redox?
Old 11-28-2006, 09:42 PM
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Yes your issue seems to be the same.

Have not changed the spark plugs yet. I am taking her to the dealership on Thursday to get the transmission mounts replaced. Deep inside, I am pretty sure that won't take care of it.

Spark plugs and cables are next.

If anyone else has experienced this, please help. I wish I could change the name of this thread.

Thanks,
esprit



Originally Posted by Ansonnn
Hey Esprit,

I've been noticing the same on my 01 S500. I don't think it's the engine mount because I open the hood and put my hand on the engine and can feel the vibration or rather the engine sputtering every couple of seconds. In the cabin, it's definitely felt and I sat in my mother-in-law's S430 and notice that it was vibration free. This definitely bothers me and I have been searching the forums for the last 30 min to see what people have said. Seems like you have tried everything. Have you changed spark plugs yet? I've been having this problem for the last 2 years but now I want to find a solution. Let me know what you find. Thanks.

Phil
Old 11-28-2006, 09:43 PM
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Originally Posted by fusion2007
what is redox?
I guess it's an injector cleaner. Did 3 of those by myself, then paid the dealership $150 to do it... no change.

Thanks,
esprit
Old 11-28-2006, 11:44 PM
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W220 S65 AMG
Originally Posted by esprit
No, no rocking while in reverse. It seems that the "rocking" is coming from the engine. In a quiet environment I can hear the sound of the engine change a little, as if the RPMs are dropping (the tachometer does not change). The rocking is most expressed while the car is in Park. It is by no means hard, I have to turn the music off (so there is no base) to feel it properly. But once you do notice it, it's pretty clear and defined. In drive or reverse, when the engine is "held down" by the transmission, it is practically unnoticeable, I only notice it because I look for it.

44k miles now, no codes, MAF has been cleaned, injection system has been cleaned, engine mounts replaced.

Any suggestions as to the next step are appreciated.

Thanks,
esprit
Mine does the same thing... it's a '03 S500. I've taken the airbox off the engine and I would stand there and listen to it for a little while and you can hear the RPMs drop for a split second then the engine sort of sputters and then it's back to normal.
Old 12-01-2006, 04:32 AM
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Hi Espirit, any updates on the transmission mount replacement?

:-)
Old 12-04-2006, 12:28 PM
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'03 S55 (79K miles)
Replace O2 sensors when you REPLACE the MAF

I don't recall if you said you cleaned the MAF because of this shudder problem? But if cleaning the MAF seems to have caused this problem....

Swapping in new O2 sensors with new MAF has been recommended in a few forums, though I don't remember reading that for this vehicle specifically. I know you only "cleaned" the MAF, but it might be worth trying, before you start monkeying around with the Tranny mount.

The ECU monitors more than just the incoming airflow (MAF) to create the ignition profile. It also checks emissions via the O2 sensors in the exhaust path. It has been programmed to look for a relationship between a change in the O2 range when the MAF range changes.
Old 12-05-2006, 05:20 PM
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Sorry I did not post right away. The dealer told me that my transmission mounts were fine and did not need to be replaced...


Originally Posted by Darknessph
Hi Espirit, any updates on the transmission mount replacement?

:-)
Old 12-05-2006, 05:24 PM
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I cleaned the MAF in an attempt to try to eliminate the problem, but it did not help.

I am thinking spark plugs and cables next ... or should I replace the O2 sensors first?

(Is it possible to change the name of this thread. It seems I am not the only one experiencing this issue )

Thanks,
esprit

Originally Posted by GrepAwk
I don't recall if you said you cleaned the MAF because of this shudder problem? But if cleaning the MAF seems to have caused this problem....

Swapping in new O2 sensors with new MAF has been recommended in a few forums, though I don't remember reading that for this vehicle specifically. I know you only "cleaned" the MAF, but it might be worth trying, before you start monkeying around with the Tranny mount.

The ECU monitors more than just the incoming airflow (MAF) to create the ignition profile. It also checks emissions via the O2 sensors in the exhaust path. It has been programmed to look for a relationship between a change in the O2 range when the MAF range changes.
Old 12-05-2006, 11:10 PM
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i've got similar issues with my 01 c320. rocking/shaking during idle. engine mounts are fine. plan on replacing the spark plugs/wires next week. others have replaced the transmission oil and also updated/flashed the computer software. keep us posted. good luck!
Old 12-06-2006, 02:29 AM
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After replacing the MAF with a new one from Bosch, the symptom was still there. The.. hellish "engine check light" came on AGAIN !

I finally bought the code reader, and the results were..

BOTH PRE-CAT O2 sensor.. SHOT!

Data:

P0130 & P0150

P0130 - O2 circuit Bank 1 Sensor 1
P0150 - O2 circuit Bank 2 sensor 1

Fuel sys1 & 2 Open loop drive
Calculated load: 10.1%
Engine coolant temp: 168F

STFT (right spelling?) Bank 1 - 0.0% Bank 2: 0.0%
LTFT Bank1 - 14.8%, Bank 2 - -14.0%

Intake manifold pressure: -5.6 in.hg

OH.. I got tons of things to do on my car.. Transmssion fluid change, eletrical seal change on the transmission, and the O2 sensor..

Stupid stealerships could not figure out these problems. I just hate them..

hope O2 sensor would cure out everything!

p.s - thanks for the reply, Espirit.


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