[cybermgm23]

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

[avin83]

Originally Posted by cybermgm23

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

Interesting. I need to change air filter soon, so I should take a look at this as well. Looks like a sensitive & expensive part that needs to be cleaned carefully.

[wallacelau]

Originally Posted by cybermgm23

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

What MAF cleaner did you buy? I read some articles that they are very vulnerable and can be damaged easily. Any tips when doing the job?

[cybermgm23]

Originally Posted by wallacelau

What MAF cleaner did you buy? I read some articles that they are very vulnerable and can be damaged easily. Any tips when doing the job?

The MAF sensor is very sensitive but needs to be to do it's job correctly. It is responsible for the air/fuel mixture in your engine. If it's dirty it can cause a lean condition, bogging down the motor on load, ruining your MPG's and leaving the computer with inaccurate information which it uses to control the transmission, among other things, thus causing wonky shifts, poor acceleration and a rough idle in gear. They cost about $300 new so handle it with care. I used CRC MAF sensor cleaner. Lots of times they get screwed up when some genius uses Carb Cleaner or Electrical Contact Cleaner on them. Don't do that. Also, I wore rubber gloves when handling it to keep my finger prints off it. When you take it out, it's located on your intake duct right behind your airbox, there will be two silver wires on one side of the sensor. Spray the cleaner on those wires liberally and then let air dry and DON'T TOUCH THEM WITH ANYTHING. Reinstall and fire it up, I hope you have as good of results as I did.

[mweisdorfer]

Originally Posted by cybermgm23

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

CRC makes a quality MAF sensor cleaner. However the N54 motor does not have a MAF. N55 & N52 do.

[GoRomeo]

Originally Posted by mweisdorfer

CRC makes a quality MAF sensor cleaner. However the N54 motor does not have a MAF. N55 & N52 do.

FYI OP has N52 thats why he us referring to MAF sensor.

[GoRomeo]

Originally Posted by cybermgm23

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

Thanks for sharing. I forgot the impact the MAF sensor does to the car performance. I cleaned mine about 3 or 4 yrs ago. I should clean it again. Sometimes I experience your symptoms you described in your post. I will also clean my air filter and oil it as well. I am due for new coils as well. Still on the originals at 135K miles. Cheers!

[e90ca]

how often are you supposed to clean the MAF sensor? When I cleaned mine about 4 months ago, the car felt great and those similar symptoms you are having went away too, but now it seems like its back already. Probably only been 6K miles now. I guess I can try cleaning it again and see if it helps.

[PhaseP]

Originally Posted by cybermgm23

When you take it out, it's located on your intake duct right behind your airbox, there will be two silver wires on one side of the sensor. Spray the cleaner on those wires liberally and then let air dry and DON'T TOUCH THEM WITH ANYTHING. Reinstall and fire it up, I hope you have as good of results as I did.

If you ask me, what fixed your issues, though most probably temporarily, you have reseated the electrical connection on the MAF sensor during this operation and for now it again has good low resistance connection on the connector pins. Wait until they work themselves a bit loose, in a few weeks or month, your symptoms may return.

This is from my own experience, and also your explanation of how you cleaned. Those two "silver" wires on one side are nothing but the leads of the intake ambient air temperature sensor, that tiny black bead at the end of those wires.

The real MAF sensor hot wire is inside the white plastic tiny duct part. Air goes from one end of that white duct, comes out from the other. In the middle somewhere is the MAF hot wire. To clean it you spray inside the white duct thingy. It is still good to clean the air temperature sensor too.

[Blueeyesredpanda]

1. Wait till the car and the sensor is 100% cooled down you spray into the sensor.
2. Do not touch the sensor with your fingers or anything
3. Wait till its completely dry (roughly 5mins max)
4. Install it!

[PhaseP]

Originally Posted by Blueeyesredpanda

2. Do not touch the sensor with your fingers or anything

You cannot touch it with your fingers anyways even if you tried, see my post above. You can still clean it though, just need to spray inside the fold of that tiny white plastic duct.

[wallacelau]

So as I understand, take the MAF sensor off from the intake duct without touching it by finger. Then spray those silver wires as well as inside the white thingy. Let it dry for around 5 mins. and then put it back. am i correct?

[PhaseP]

There is no need to clean those two wires that are on the side. It would be good measure to clean the black bead at the end of those but not essential. You do need to spray inside the white thingy good. Wait a bit then put together.
That said I suggest get a good contact cleaner and spray clean the MAF connector pins while you are there.

[cybermgm23]

Originally Posted by PhaseP

If you ask me, what fixed your issues, though most probably temporarily, you have reseated the electrical connection on the MAF sensor during this operation and for now it again has good low resistance connection on the connector pins. Wait until they work themselves a bit loose, in a few weeks or month, your symptoms may return.

This is from my own experience, and also your explanation of how you cleaned. Those two "silver" wires on one side are nothing but the leads of the intake ambient air temperature sensor, that tiny black bead at the end of those wires.

The real MAF sensor hot wire is inside the white plastic tiny duct part. Air goes from one end of that white duct, comes out from the other. In the middle somewhere is the MAF hot wire. To clean it you spray inside the white duct thingy. It is still good to clean the air temperature sensor too.

Thanks for the tip, I thought the two external silver wires were the hot wires. I took it out and cleaned it again as you described. Seems that the benefits are still there so we'll see how it goes. I'm anxious to see if I get better mpg's.

[oolas3]

Is MAF cleaning recommended even if you are not having any problems?

[hassmaschine]

Or just delete it. Problem solved.

[galahad05]

Originally Posted by mweisdorfer

CRC makes a quality MAF sensor cleaner. However the N54 motor does not have a MAF. N55 & N52 do.

Wait, the N55 has a MAF?!?

Damn, yet another difference between the N54s and their follow-ons.
I swear, next time I will NOT get the first model year for an engine with BMW.

[hassmaschine]

Originally Posted by galahad05

Wait, the N55 has a MAF?!?

Damn, yet another difference between the N54s and their follow-ons.
I swear, next time I will NOT get the first model year for an engine with BMW.

I don't see that as really much of an advantage or a reason to want one vs the other. And actually, lots of N52s and N53s came with no MAF either - the DME's were designed to run without them, they were added later in certain markets.

[STR8-6IX]

Originally Posted by cybermgm23

I'm not sure if this has been mentioned before but I had such good results today that I thought I'd share. For about six months I've noticed a rough idle in D, sluggish throttle response and hard shifting up and down. The dealer said nothing was wrong with the car when I took it in last May so I've been just living with it. Then I read an article recently about the MAF; what it does, how it works and what it can affect when sending inaccurate readings to the computer. All three of my symptoms were listed so I bought some MAF cleaner and cleaned the MAF today. Wow! What a difference. All of the issues above have disappeared and the car drives like new. No more uneven throttle, no more rough idle and no more rough shifting. If you're having similar issues, try it. It took me all of 15mins and $8.

if you are at 100k, consider a transmission fluid change. it will help smooth out the shifts.

where is the MAF sensor on this car? at what mileage does it typically become dirty?

[hassmaschine]

it's in the muffler.

[Hdpz2]

I tried cleaning it to clear a P114D code but accidentally slightly scuffed it. The code is pending currently , should I get a new one ?

[cybermgm23]

really sorry I mentioned any of this