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Discussion Starter #1 (Edited)
I have a problem, a nice one too!

You see, I disconnected the drivers side MAF and ran on only one MAF and the car was fine. So the other day, i removed the passenger side MAF and am currently running on the Drivers side MAF and there is definitly a problem.

After running it in for a few miles, the car began to lose torque. But.... when I floor it, it sounds like a supercharger!!!!! It sounds great! It feels crap, but it sounds great!!!

People turn to look and ask me if my beast is supercharged!

:haha:


Abdulla... eat your heart out! :M5launch:
 

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The glass is always 1/2 full with ahmed :) cherrsagai
 

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lol.. you nutta..your driving about with just one maf sensor, and the other maf removed, did you fill the gap/hole with anything? if not, you'll be sucking in "un-filtered" air directly into the engine plenum... not worth the risk dude, try 2 brand new mafs...
 

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The sound is probably the Vanos moving the camshafts to netural position, then you get a very nice sound but no low-rev torque.

The cause is probably broken cam-shaft sensor, or the DME (the ECU) going int a backup-mode because of the lack of proper signals from both MAFs.

The ECU uses an Intake Air Temperature sensor of the left side MAFs, but not from the other MAF. If you disconnect that temperature signal the DME will not know how warm the outside air is, and has to assume it is rather warm.

David
 

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Discussion Starter #7
I have the UFMotorsport IATS installed. Does that mean that my driver side MAF is pretty much useless to me? The reason why i am disconnecting the MAF's is because my car mis-fires and cuts off when both MAF's are connected.

I discovered this morning that the "air" sound coming from my car, ( the one that sounds like a supercharger ) is still there. Its not related to me disconnecting the MAFs, it was just a coincidence that it happened two nights ago.

What could be causing this sound ( sounds like excessive air blowing ) and loss of power?
 

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Hello Ahmed,

The MAF does two things: it measures air temperature and it measures air flow by mass (gram / s).

As you have the UFMotorsport IATS (Intake Air Temperature Sensor) your car has been rewired to replace the temperature signal from the left MAF with the signal from this sensor.

Both MAFs still report airflow to the DME (ECU computer), and both MAF signals are still needed for proper operation. When you run with just one MAF connected I would assume the DME guesses that the signal from the missing MAF would be roughly the same as from the one that is conected.

If you have a hissing sound like air going through a small hole, it might be a leak in the air tubes going from the MAFs to the plenum chamber (airbox) on top of the engine.

I would definitely try to locate that leak immediately and fix it with some tape, the drive to a mechanic to have it fixed properly.

Running the engine with improper air/fuel mixture, which is the result if the MAF signals are not accurate, is not good at all for the engine.

Hope this is of use to you!

David
 

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Ahmed:

My friend you are killing me. I did connect the one MAF as a means to control the problem and allow for temporary drivability not as the means for a permanent cure. I though that by now you would have had the local BMW technicians use that information as the basis for the final repair.

As I shared the two MAFs are used to collect data but ultimately they create a single averaged value for the DME to use to calculate the air flow/load so you will be far better served to correct rather than accept this situation.

Call me when you have time

Regards

Shadowman
 

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LOL!! You crack me up, Ahmed. You have one of the sweetest and fastest rides on the planet, yet you will cripple it to hear the sound it makes*sigh*. A kid at heart!:1: Although, I suppose all car enthusiasts are kids at heart. :noSMG:
 

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Discussion Starter #11
OK Guys, my appointement at the dealers is tomorrow. I already explained to the technician the situation, and he proposed a direct swap of both MAF's to see how it goes.

Sorry Bill, I really didnt have much time to take the car in this week, but i have been driving it very little and will take her in tomorrow!

In regards to the excessive air blowing sound, the problem was right in front of me and i didnt even see it! Tried to move the fan manually, and its jammed! So my fan clutch is messed up!!!

I think i need to camp outside the dealer from now on!
 
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