Can a MAF be fitted upside down??
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MBWorld Fanatic!
Joined: Feb 2011
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From: London, UK
W212 - E63 AMG
Can a MAF be fitted upside down??
So after speaking to the guy at Kleemann, he suggested that I start my investigation into my power shortage by investing in some new MAF sensors, esp as the car is nearly 6 years old now. I figured, I'd take them out and give them a clean...if i feel the slightest difference, I'll use that as justification to buy some new ones from the dealer.
Just had a look and it seems as though the left MAF was fitted upside-down...is that normal?? Surely it can't be...the sensor clip would always be facing upwards for ease of removal. I know on other cars, fitting a MAF the wrong way can lead to all kinds of running issues...
Also...why the hell are the rubber sleeves on the sensor clip all mangled as though a shark has bitten through them??
This is the orientation of how they came out...
Comparing part numbers...
So yeah....pretty odd to me. I just gave them a good clean with carb cleaner and giving them a bit of time to dry now before refitting. I'm going to fit the left sensor in the same orientation as the right one...it just seems like the right way to do it. Fingers crossed it's something as simple as this as to why my car is so down on power. lol sods law though that it probably won't make even the slightest difference
Just had a look and it seems as though the left MAF was fitted upside-down...is that normal?? Surely it can't be...the sensor clip would always be facing upwards for ease of removal. I know on other cars, fitting a MAF the wrong way can lead to all kinds of running issues...
Also...why the hell are the rubber sleeves on the sensor clip all mangled as though a shark has bitten through them??
This is the orientation of how they came out...
Comparing part numbers...
So yeah....pretty odd to me. I just gave them a good clean with carb cleaner and giving them a bit of time to dry now before refitting. I'm going to fit the left sensor in the same orientation as the right one...it just seems like the right way to do it. Fingers crossed it's something as simple as this as to why my car is so down on power. lol sods law though that it probably won't make even the slightest difference
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2005 E55
they are supposed to be upside down on one side.do NOT put the other one in the same way or u will have issues.if you look at the sensor and see the opening where the air flows into it and see the direction of the air coming in from the airbox it will make sense to you why one is upside down.
if you put it in like the other side it will have the air port facing behind the airbox and not be able to read the incoming air.
if you put it in like the other side it will have the air port facing behind the airbox and not be able to read the incoming air.
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MBWorld Fanatic!
Joined: Feb 2011
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From: London, UK
W212 - E63 AMG
lol, thanks man - i just just refitted them and came back to post but saw your message above.
Yeah there is a guide pin on the maf that means it can only go in one way anyway.
Damnit, well it was worth a try. I guess anyone would consider the same if their car is 40hp down after cams and a tune
Refitted and started ok. I'll pass judgement on the 'clean' later. Doubt it'll do anything tbh, but I may still buy a new pair of sensors just to rule it out.
Yeah there is a guide pin on the maf that means it can only go in one way anyway.
Damnit, well it was worth a try. I guess anyone would consider the same if their car is 40hp down after cams and a tune
Refitted and started ok. I'll pass judgement on the 'clean' later. Doubt it'll do anything tbh, but I may still buy a new pair of sensors just to rule it out.
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
The rubber harness fittings may have decomposed from heat or chemicals or something but really they look like they have been chewed by mice. Mice can do a lot of damage to wiring harnesses under the hood.
Senior Member
Joined: Apr 2007
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From: Norcal/Socal
C63 E63
I have seen mice do a lot of damage. Might have chewed some wires which were then disturbed when the cams were being installed, causing the lack of power.
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From: Denham Springs,LA
'12 C63 Black Series, '12 ML350 BlueTech
As you figured it out. MAFS can only go one way due to that pin guide. Any changes in power since you cleaned them up?
Also your engine bay needs a clean up. No wonder your rubber harness fittings are chewed by mice.
Also your engine bay needs a clean up. No wonder your rubber harness fittings are chewed by mice.
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MBWorld Fanatic!
Joined: Feb 2011
Posts: 1,752
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From: London, UK
W212 - E63 AMG
I can't be bothered to clean the engine...not in this miserable country that rains all the damn time
As for improvements with the cleaned maf sensors....sadly not man. Makes it harder for me to justify spending the money on a new pair of mafs now.
Have members previously reported notable improvements in the power delivery after a new set of mafs were installed?
As for improvements with the cleaned maf sensors....sadly not man. Makes it harder for me to justify spending the money on a new pair of mafs now.
Have members previously reported notable improvements in the power delivery after a new set of mafs were installed?
