MAF Sensor Cleaning DIY (N52)
05-30-2010, 02:43 AM
#31
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06-13-2010, 04:28 PM
#32
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My Ride: '04 545i, sport pkg, premium sound, sprint booster,
Hey Vlad, great DIY!
The only problem I had was I didn't have the proper
torx head adaptor. But I found a work around! 
At least for us 545i/550i (N62) guys and gals.
I followed your directions to the T until I came to those torx head screws, then I thought "What don't I just remove the hose in between the engine and where the MAF is housed?". So I proceeded to do that.
First I pulled off the hose on the top next to the engine that leads to the pressure regulating valves on either side of the engine (shout out and kudos to e6t.lab.rat for that fine DIY https://5series.net/forums/topic/853...e/page__st__45, I did that one yesterday)! I put it safely out of the way until it's time to be reconnected.
Next I loosened the screws with a flat tip screwdriver on both ends of the hose until the steel bands moved freely in either direction. I just simply pulled off both ends from where they were connected. From here I can now see the throttle valve opening on the engine and on the other side the MAF hanging securely inside the hose still attached to the air filter assembly.
Okay for the next step I have a T-30 torx head screwdriver and a couple of shop towels ready to go. At the base of where the air filter assembly and the MAF housing attach to each other, I placed the shop towels there to form a catch area. The reason for the towels is, if your anything like me you will have an moment and drop the bolt down into the bowels of the engine compartment. Don't go there! Next I unscrewed and removed the two bolts with the T-30 that secure and the air filter assembly and the MAG housing and placed them safely out of the way. Then I became aware that there is a rubber O-ring that rests just inside the opening of the air filter assembly. I made sure that it was firmly seated there before reassemly.
With the MAF sensor still securely fastenend inside the housing, I now sprayed the sensor from both sides of the housing's openings. Okay the sensor is now clean.
VERY IMPORTANT!!! Before I reassembled everything, I thoroughly cleaned inside the hoses, the air filter assembly opening and especially the opening for the throttle valve. It would be a very bad thing to have any debris enter into the engine!
After I finished cleaning, I simply reversed the steps I performed earlier. I made sure that the hoses were firmly seated in there proper places and reconnected the MAF to the wiring harness. My baby girl started up just fine!
Other 5 series vehicles may be able to perform the same steps I just outlined. There will obviously be a difference on how the MAF is connected between the air filter assembly and the throttle valve opening. Use your own discretion and take your time.
The only problem I had was I didn't have the proper
torx head adaptor. But I found a work around! At least for us 545i/550i (N62) guys and gals.I followed your directions to the T until I came to those
torx head screws, then I thought "What don't I just remove the hose in between the engine and where the MAF is housed?". So I proceeded to do that. First I pulled off the hose on the top next to the engine that leads to the pressure regulating valves on either side of the engine (shout out and kudos to e6t.lab.rat for that fine DIY https://5series.net/forums/topic/853...e/page__st__45, I did that one yesterday)! I put it safely out of the way until it's time to be reconnected.
Next I loosened the screws with a flat tip screwdriver on both ends of the hose until the steel bands moved freely in either direction. I just simply pulled off both ends from where they were connected. From here I can now see the throttle valve opening on the engine and on the other side the MAF hanging securely inside the hose still attached to the air filter assembly.
Okay for the next step I have a T-30 torx head screwdriver and a couple of shop towels ready to go. At the base of where the air filter assembly and the MAF housing attach to each other, I placed the shop towels there to form a catch area. The reason for the towels is, if your anything like me you will have an
moment and drop the bolt down into the bowels of the engine compartment. Don't go there! Next I unscrewed and removed the two bolts with the T-30 that secure and the air filter assembly and the MAG housing and placed them safely out of the way. Then I became aware that there is a rubber O-ring that rests just inside the opening of the air filter assembly. I made sure that it was firmly seated there before reassemly.With the MAF sensor still securely fastenend inside the housing, I now sprayed the sensor from both sides of the housing's openings. Okay the sensor is now clean.
VERY IMPORTANT!!! Before I reassembled everything, I thoroughly cleaned inside the hoses, the air filter assembly opening and especially the opening for the throttle valve. It would be a very bad thing to have any debris enter into the engine!
After I finished cleaning, I simply reversed the steps I performed earlier. I made sure that the hoses were firmly seated in there proper places and reconnected the MAF to the wiring harness. My baby girl started up just fine!
Other 5 series vehicles may be able to perform the same steps I just outlined. There will obviously be a difference on how the MAF is connected between the air filter assembly and the throttle valve opening. Use your own discretion and take your time.
10-09-2011, 01:21 PM
#35
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My Ride: 07 530i Mystic Blue
Thank you for posting pix/detailed procedure. It only took a few minutes to perform all the steps once I got the cleaner from Autozone ($6.99).
When it comes to DIY, I am definitely a noob but this one was easy. Everyone should attempt this
When it comes to DIY, I am definitely a noob but this one was easy. Everyone should attempt this
10-10-2011, 12:08 PM
#36
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My Ride: 2007 BMW 550i Sport Pkg, 6MT
I did and I didn't notice difference.
I have 48k on my car with stock air filter. Maybe if you use oil based filter, such as K&N, you need to clean it often.
I have 48k on my car with stock air filter. Maybe if you use oil based filter, such as K&N, you need to clean it often.
03-25-2012, 11:13 AM
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Hi All, new to this site and a new BMW owner. Recently purchased an 07 520d Msport Tourer. It so nice to have a car that feels so solid after all these years.
I have noticed a bit of a problem, only a week after picking the car up. I would take the car back to the dealer but its a 100 mile round trip. So I am wondering if my fault could be cured by cleaning the MAF sensor. You have certainly made it look very easy.
My car drives fine at normal speeds but when the revs drop below 2500 in a higher gear (say 3rd at 30mph and 4th at 40mph) the engine starts to get lumpy. Almost as if it is in too high a gear, however a diesel should be able to pull from low down revs - my older Zafira did without a murmer. The only way to stop this is to change down, therfore is a 30 limit you find yourself forced into 2nd gear!
What are your thoughts on this problem?
Thanks for your help
I have noticed a bit of a problem, only a week after picking the car up. I would take the car back to the dealer but its a 100 mile round trip. So I am wondering if my fault could be cured by cleaning the MAF sensor. You have certainly made it look very easy.
My car drives fine at normal speeds but when the revs drop below 2500 in a higher gear (say 3rd at 30mph and 4th at 40mph) the engine starts to get lumpy. Almost as if it is in too high a gear, however a diesel should be able to pull from low down revs - my older Zafira did without a murmer. The only way to stop this is to change down, therfore is a 30 limit you find yourself forced into 2nd gear!
What are your thoughts on this problem?
Thanks for your help
04-21-2012, 11:51 AM
#38
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My Ride: 2006 BMW 530I
Model Year: 530i
Thank you for the write up! That was very useful info!
I have been getting the SES that keeps popping up recently, stating that I have misfire detection cylinder 4 in 3. Since I already changed new spark plugs and two additional new coils, I said WTH and gave it a try...
With such concise write up, it really helped me complete the job! The wires were as clean as it could be at 70,400 miles from my initial observation. In any case, I used the whole can today and still can not feel the 4 to 10 horse power at the wheels (as stated on the can of the CRC/Mass Air Flow Sensor Cleaner). I complained to the manager at Pepboys (friend of mine) and he said I just don't focus hard enough. 
All and all, I would not know what it looks like if I had not tried it.
Again, thank you!
I have been getting the SES that keeps popping up recently, stating that I have misfire detection cylinder 4 in 3. Since I already changed new spark plugs and two additional new coils, I said WTH and gave it a try...
With such concise write up, it really helped me complete the job!
The wires were as clean as it could be at 70,400 miles from my initial observation. In any case, I used the whole can today and still can not feel the 4 to 10 horse power at the wheels (as stated on the can of the CRC/Mass Air Flow Sensor Cleaner). I complained to the manager at Pepboys (friend of mine) and he said I just don't focus hard enough. All and all, I would not know what it looks like if I had not tried it.
Again, thank you!
05-12-2012, 06:10 PM
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