could this be air flow sensor?

bmwdiesel · 12-23-2019, 10:30 AM

so I was going to charge the battery by plugging the engine bay plus and minus connections overnight and it was dark and the boot was falling on my head as it was parked in the slope, and I put the piece of wood between the boot and air flow sensor (at the time I didn't know)
and then in the next couple of days I noticed the car doesnt go up to the speed, after 2000rpm there is no power basically and I can't overtake as I could couple days ago...

I did diagnostics yesterday and it said some faults and air meter was there in Info section at INPA not in error and I deleted it and no more faults showed. Today I drove it again and when I put Requested vs actual values in INPA readout, the actual air was jumping up and down. I opened the boot and puished the airflow electrical plug deeper into the socket that seemed to fix the jumping values and the air flow showed matching values to the desired ones, and I thought ok this was it, but then when I went for a drive, it still didnt have any power and also I tried to unplug the air flow meter to see the difference, but the result was the same, no power...
I changed this air flow last year omg for 200 bucks...I hope I didnt break it.

lastly, my car has multiple issues, but only one that show is the fuel filter but it has been for a long time, because it's the heater faulty, not the filter and didnt have a chance to change it yet.

another thing is that the boost was somewhat weaker than requested in actual vs desired values and when I put the leg off the pedal the actual boost stayed hanging there higher than requested one....not sure what could that mean

another thing I noticed was the brake pedal was stiff while cold engine, but seemed to ease up after it warmed...(it ocassionally stiffens up for brief period btw, but this time I am thinking it could be loss of boost/vacuum?

so now i dont know whether I killed my air flow meter, or whether there is some other fault, INPA doesnt show any fault after I deleted old ones basically, so I dont know but the engine has no power no low revs no high revs...

Mik325tds · 12-23-2019, 11:36 AM

Usually, issues with the MAF are detected quite easily by the engine. If you don't have a fault there, I'd suggest going after vacuum issues. All actuators for the turbos are vacuum controlled so a loss of vacuum could easily be the cause for your issues.

bmwdiesel · 12-23-2019, 01:51 PM

thanks well I assume so, but i heard about cases where ppl actually had to remove/change MAF to find out if it was actually faulty MAF?? anyone know any specific case that would confirm this?

as I mentioned I unplugged MAF to see whether it's gonna behave differently, but it was the same. Previously I had problem with MAF and this made a difference back then and I even drove without MAF few hundred miles with no issues and even good performance and fuel consumption btw...

Yozh · 12-24-2019, 12:43 AM

Sounds like you have multiple issues here. You need to tackle them one star time. I agree with Mik.

12-23-2019, 10:30 AM	#1
bmwdiesel Private 14 Rep 84 Posts Drives: 335d 2007 Join Date: May 2018 Location: old continent iTrader: (0)	could this be air flow sensor? so I was going to charge the battery by plugging the engine bay plus and minus connections overnight and it was dark and the boot was falling on my head as it was parked in the slope, and I put the piece of wood between the boot and air flow sensor (at the time I didn't know) and then in the next couple of days I noticed the car doesnt go up to the speed, after 2000rpm there is no power basically and I can't overtake as I could couple days ago... I did diagnostics yesterday and it said some faults and air meter was there in Info section at INPA not in error and I deleted it and no more faults showed. Today I drove it again and when I put Requested vs actual values in INPA readout, the actual air was jumping up and down. I opened the boot and puished the airflow electrical plug deeper into the socket that seemed to fix the jumping values and the air flow showed matching values to the desired ones, and I thought ok this was it, but then when I went for a drive, it still didnt have any power and also I tried to unplug the air flow meter to see the difference, but the result was the same, no power... I changed this air flow last year omg for 200 bucks...I hope I didnt break it. lastly, my car has multiple issues, but only one that show is the fuel filter but it has been for a long time, because it's the heater faulty, not the filter and didnt have a chance to change it yet. another thing is that the boost was somewhat weaker than requested in actual vs desired values and when I put the leg off the pedal the actual boost stayed hanging there higher than requested one....not sure what could that mean another thing I noticed was the brake pedal was stiff while cold engine, but seemed to ease up after it warmed...(it ocassionally stiffens up for brief period btw, but this time I am thinking it could be loss of boost/vacuum? so now i dont know whether I killed my air flow meter, or whether there is some other fault, INPA doesnt show any fault after I deleted old ones basically, so I dont know but the engine has no power no low revs no high revs... Last edited by bmwdiesel; 12-23-2019 at 11:35 AM..
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12-23-2019, 11:36 AM	#2
Mik325tds Major 806 Rep 1,191 Posts Drives: 335d M-Sport Join Date: Jul 2014 Location: Greater Detroit iTrader: (0)	Usually, issues with the MAF are detected quite easily by the engine. If you don't have a fault there, I'd suggest going after vacuum issues. All actuators for the turbos are vacuum controlled so a loss of vacuum could easily be the cause for your issues.
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12-23-2019, 01:51 PM	#3
bmwdiesel Private 14 Rep 84 Posts Drives: 335d 2007 Join Date: May 2018 Location: old continent iTrader: (0)	thanks well I assume so, but i heard about cases where ppl actually had to remove/change MAF to find out if it was actually faulty MAF?? anyone know any specific case that would confirm this? as I mentioned I unplugged MAF to see whether it's gonna behave differently, but it was the same. Previously I had problem with MAF and this made a difference back then and I even drove without MAF few hundred miles with no issues and even good performance and fuel consumption btw...
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12-24-2019, 12:43 AM	#4
Yozh Colonel 870 Rep 2,615 Posts Drives: 2011 335d M-Sport Join Date: Mar 2014 Location: Wet Coast iTrader: (4)	Sounds like you have multiple issues here. You need to tackle them one star time. I agree with Mik.
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