MAF sensor, why?
Thread Starter
Member
Joined: May 2008
Posts: 90
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From: Calgary,Alberta, Canada.
2003 CL500
MAF sensor, why?
Does any body know why the MAF sensor's are prone to breakdown on these cars? I mean, they are on hundreds/thousands of different makes/models with less prestige and theirs last MUCH longer.
It is also a Bosch, so does fault go to them or was it designed at Benz and given to Bosch to build?
There just has to be a solution to this problem, am I wrong?
It is also a Bosch, so does fault go to them or was it designed at Benz and given to Bosch to build?
There just has to be a solution to this problem, am I wrong?
Senior Member
Joined: Feb 2008
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CL500
Does any body know why the MAF sensor's are prone to breakdown on these cars? I mean, they are on hundreds/thousands of different makes/models with less prestige and theirs last MUCH longer.
It is also a Bosch, so does fault go to them or was it designed at Benz and given to Bosch to build?
There just has to be a solution to this problem, am I wrong?
It is also a Bosch, so does fault go to them or was it designed at Benz and given to Bosch to build?
There just has to be a solution to this problem, am I wrong?
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Have
you cleaned it? CRC brand maf cleaner.
what codes did you pull that led you to believe it had failed?
When did you last change your fuel filter?air filter not k/n
Have you checked for leaks in the intake system?
They don't fail that often.
If it did only $200 to replace.
Post the codes.
what codes did you pull that led you to believe it had failed?
When did you last change your fuel filter?air filter not k/n
Have you checked for leaks in the intake system?
They don't fail that often.
If it did only $200 to replace.
Post the codes.
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John Deere
Do what Ohlord says, but in the meantime, here is why they fail:
MB buys Bosch MAFs that are manufactured to very specific tolerances. This is also true of O2 sensors. The Bosch assembly line has one for MB and one for everyone else (I'm generalizing a little here). It is somewhat like the infamous $900 hammers the army used to buy in the 1980's. Part of that price was procurement fraud and part was that the US Army demanded a hammer be 99.999% within exact size/weight. Could you smack a nail with a hammer that is 99.9% within spec? Of course. But the machining required for the higher spec is custom and so costs a lot extra.
MB spec sensors are like Army hammers. A regular Bosch MAF will do just fine in a Toyota or BMW, but the MB computer will not accept that range of values that are ok for other manufacturer computer chips.
MB buys Bosch MAFs that are manufactured to very specific tolerances. This is also true of O2 sensors. The Bosch assembly line has one for MB and one for everyone else (I'm generalizing a little here). It is somewhat like the infamous $900 hammers the army used to buy in the 1980's. Part of that price was procurement fraud and part was that the US Army demanded a hammer be 99.999% within exact size/weight. Could you smack a nail with a hammer that is 99.9% within spec? Of course. But the machining required for the higher spec is custom and so costs a lot extra.
MB spec sensors are like Army hammers. A regular Bosch MAF will do just fine in a Toyota or BMW, but the MB computer will not accept that range of values that are ok for other manufacturer computer chips.
Super Member
Joined: Oct 2005
Posts: 584
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From: Northern NJ
E90 N54 & W251
+2 on Ohlord's post. It's best to clean first as you may have a good sensor that's just dirty. In my case, the sensor was bad.
RBrenton,
Nice post! I had no idea and always thought they were the same. I bought an OEM MAF so I feel better now.
RBrenton,
Nice post! I had no idea and always thought they were the same. I bought an OEM MAF so I feel better now.
Thread Starter
Member
Joined: May 2008
Posts: 90
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From: Calgary,Alberta, Canada.
2003 CL500
I did the clean with CRC cleaner, reset codes and within 10min of driving the car did a slight stumble upon acceleration and idle.
I then read on a post on this forum that if you disconnect the MAF the car wouldnt stumble upon acceleration or idle. I disconnected the MAF and no stumble. I decided to order new from my dealer at cost plus 10%. The total bill in CDN funds was $413.00.
I put in new sensor and reset codes and voila! No more ceck engine light. I will post the codes asap as I cant rember and Im not home for a couple days.
I geuss the tighter values on the Benz computers makes sense. Just wish it was longer lasting I guess. My car has 36,000 miles on it. Seems like an early failure to me.
I then read on a post on this forum that if you disconnect the MAF the car wouldnt stumble upon acceleration or idle. I disconnected the MAF and no stumble. I decided to order new from my dealer at cost plus 10%. The total bill in CDN funds was $413.00.
I put in new sensor and reset codes and voila! No more ceck engine light. I will post the codes asap as I cant rember and Im not home for a couple days.
I geuss the tighter values on the Benz computers makes sense. Just wish it was longer lasting I guess. My car has 36,000 miles on it. Seems like an early failure to me.
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Thread Starter
Member
Joined: May 2008
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From: Calgary,Alberta, Canada.
2003 CL500
Im only using stock filters and parts on the car. Its my cruiser so no need for speed. I change em bout every 10,000km.
That is two maf's since new, am i doin something wrong?
That is two maf's since new, am i doin something wrong?
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Did
you clean the mass air sensor by taking the sensor out of the maf body to clean it?
are you using fuel with a high ethanol %?
If you cleaned it in place,the stumble may have been from unevaporated maf cleaner.
Dealer part should have a warranty.
2 in 36k is unusual,fire off a letter to mb of Canada certified post and see what response you get.Worth a try.Tell them what you paid,and you might have to consider another make next time
are you using fuel with a high ethanol %?
If you cleaned it in place,the stumble may have been from unevaporated maf cleaner.
Dealer part should have a warranty.
2 in 36k is unusual,fire off a letter to mb of Canada certified post and see what response you get.Worth a try.Tell them what you paid,and you might have to consider another make next time
Thread Starter
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Joined: May 2008
Posts: 90
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From: Calgary,Alberta, Canada.
2003 CL500
Its funny you mention ethanol. Because come to think of it both times it failed were shortly after using Mohawk brand gas witch is high in ethanol.
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
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Posts: 5,143
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From: South Orange County, CA
4 wheels
Its funny you mention ethanol. Because come to think of it both times it failed were shortly after using Mohawk brand gas witch is high in ethanol.
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
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Joined: Apr 2007
Posts: 6,171
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Long term fuel trim is set
in the ecu after several driving cycles,sort of like a short term memory so the car can go into closed loop operation quickly.The ecu gets use to the FT of brand A high test 91 octane and then you put in some 91 octane with 10% ethanol and it falls out of that very narrow range of values that the emissions system in the computer are set as ideal air /fuel ratios.You change gas back to brand A ,and sometimes it will readapt back into the narrow correct range again.I drove 1400 miles in 19 hours and not a blink of a light,got into seattle and gassed up at an arco with 10%ethanol and Bam p0170 and p0173 just like that.If I could figure out a piggy back resistor to solder on the wire and widen the range I could make a few more million bucks hopefully before the smog police got to me
A. try the fuel change
B. erase the code and readapt the ecu drive cycle.Google ohlord generic drive cycle.
C. complain nicely to the dealer where you got the Maf for 400CAN
D.Punt
sometimes guys that think if high test like 91 is required that they will get more power with racing fuel like 103 octane and it is so highly oxygenated it can also make the maf go crazy.
and you are also up at about 3500 ft. correct?So 91 octane is like 87 mixed with ethanol a sure tripper of the maf.
hopefully before the smog police got to meA. try the fuel change
B. erase the code and readapt the ecu drive cycle.Google ohlord generic drive cycle.
C. complain nicely to the dealer where you got the Maf for 400CAN
D.Punt
sometimes guys that think if high test like 91 is required that they will get more power with racing fuel like 103 octane and it is so highly oxygenated it can also make the maf go crazy.
and you are also up at about 3500 ft. correct?So 91 octane is like 87 mixed with ethanol a sure tripper of the maf.
Last edited by ohlord; Nov 9, 2008 at 01:21 AM.
Thread Starter
Member
Joined: May 2008
Posts: 90
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From: Calgary,Alberta, Canada.
2003 CL500
we are at about 3500 and with that 10% ethanol it makes perfect sense that it would cause problems, man im stupid.
We can only get 91 octane up here, should i be running an octane booster? I have heard bad things about that to though.
We can only get 91 octane up here, should i be running an octane booster? I have heard bad things about that to though.
Senior Member
Joined: Aug 2007
Posts: 285
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From: Calgary Alberta Canada
2001 Mercedes CL500 2006 E350 4-matic
Its funny you mention ethanol. Because come to think of it both times it failed were shortly after using Mohawk brand gas witch is high in ethanol.
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
Never put 2 and 2 together because they wouldnt fail till a couple of tanks had gone through. I usually use Esso gas but these two times it was Mowhawk or bust!
When I cleand the maf I actually took the sensor out of the maf body itself and cleaned it.
So.... ethanol bad?
The Mohawk gasoline observation seems to be correct. Same problem here...Altitude effects have been mentioned to me by the technician at Lone Star. Nice day for a drive today in Calgary...12 Celsius..
Super Member
Joined: Oct 2005
Posts: 584
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From: Northern NJ
E90 N54 & W251
Where did you get the security Torx tool? I am unable to remove the sensor - and therefore clean it in the maf body.
The Mohawk gasoline observation seems to be correct. Same problem here...Altitude effects have been mentioned to me by the technician at Lone Star. Nice day for a drive today in Calgary...12 Celsius..
The Mohawk gasoline observation seems to be correct. Same problem here...Altitude effects have been mentioned to me by the technician at Lone Star. Nice day for a drive today in Calgary...12 Celsius..
Calgary,
I bought a 100 piece bit set that includes a bunch of of torx, hex and security hext bits from Harbor Freight for $9.99. You can't go wrong.
Here's the set I have:
http://www.harborfreight.com/cpi/cta...emnumber=91310
Senior Member
Joined: Aug 2007
Posts: 285
Likes: 27
From: Calgary Alberta Canada
2001 Mercedes CL500 2006 E350 4-matic
Calgary,
I bought a 100 piece bit set that includes a bunch of of torx, hex and security hext bits from Harbor Freight for $9.99. You can't go wrong.
Here's the set I have:
http://www.harborfreight.com/cpi/cta...emnumber=91310
I bought a 100 piece bit set that includes a bunch of of torx, hex and security hext bits from Harbor Freight for $9.99. You can't go wrong.
Here's the set I have:
http://www.harborfreight.com/cpi/cta...emnumber=91310
Senior Member
Joined: Aug 2007
Posts: 285
Likes: 27
From: Calgary Alberta Canada
2001 Mercedes CL500 2006 E350 4-matic
I am in Braeside....IF you don't have the 03 CL500 brochure, let me know - I have one for you...Calgary
Senior Member
Joined: Aug 2007
Posts: 285
Likes: 27
From: Calgary Alberta Canada
2001 Mercedes CL500 2006 E350 4-matic
