High Pitch Whistling Noise at Cold Start
06-26-2012, 03:46 AM
#11
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Update: the whistling noise seems to be the crankcase ventilation system. It disappears when you pull out the dipstick.
Even though the CCVs look fine will replace them in the next few days and check all related hoses. Hopefully it's not the issue described at SIB 11 01 07, where you have to replace the whole passenger side valve cover.
Even though the CCVs look fine will replace them in the next few days and check all related hoses. Hopefully it's not the issue described at SIB 11 01 07, where you have to replace the whole passenger side valve cover.
06-28-2012, 07:34 AM
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My Ride: 545I and a half dozen other rides
anyway to record the noise?
can you check again to see if this is related to the air pump? it should be under the right headlight and only on when engine is cold.
can you check again to see if this is related to the air pump? it should be under the right headlight and only on when engine is cold.
06-28-2012, 07:59 AM
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My Ride: 545i 2004, SMG, Sport, Nav, Logic-7, Bluetooth phone retrofit
[quote name='AchtungE60' timestamp='1340056505' post='1451108']
where do this come into play on your car? before the throttle body?
http://realoem.com/b...278&hg=11&fg=45
The vacuum pump isn't involved with the intake on that engine. Since it's Valvetronic, there's essentially no vacuum on the intake manifold, so they added a vacuum pump to provide vacuum for crankcase ventilation and the brake booster. It's driven by the passenger side exhaust camshaft.
where do this come into play on your car? before the throttle body?
http://realoem.com/b...278&hg=11&fg=45
The vacuum pump isn't involved with the intake on that engine. Since it's Valvetronic, there's essentially no vacuum on the intake manifold, so they added a vacuum pump to provide vacuum for crankcase ventilation and the brake booster. It's driven by the passenger side exhaust camshaft.
06-28-2012, 09:45 AM
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My Ride: Modded 2010 Carbon Black M5 SMG and Modded 2008 Dinan 550i Sport
I had the same whistle sound which was air traveling through a crack in the pressure regulating valve. See the DIY below. It's very easy.
https://5series.net/forums/topic/853...gulating+valve
https://5series.net/forums/topic/853...gulating+valve
06-29-2012, 11:32 AM
#17
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Looks like the misfiring is gone. Maybe it just went away by itself (I almost never leave the car idling after a cold start for too long, so it doesn't misfire too often). Maybe resetting DME adaptation values helped. After the reset, it hasn't misfired even when idling for 2-3 minutes after a cold start.
Just a recap, if someone has similar issues. Problem: cyl 4&8 start misfiring after 40sec-1min when the car is cold. Nothing changed with new spark plugs and swapped coils. Solution: reset DME adaptation values (I used DIS, however INPA and other diagnostic software should work).
Back to the whistling noise
healthservices
Doesn't seem to be air pump related.
Here are 3 videos. First one: activate air pump with DIS, without engine running. Sounds ok to me.
2nd video. Start the car. There's a DIS screen that shows air pump status. It's active at first, you hear the whistling noise. At 0:20 it stops by itself, 0:33 starts again. 0:38 - 0:40 I pulled the dipstick out and you can hear the noise stopped. 0:48 the DIS shows that the air pump is off, but the noise is still there.
So the noise was on for 2 mins.
As much as I tried, I can't point where exactly the noise is coming from. Maybe because it's a high frequency noise, it seems that it is everywhere.
I wrote before that restarting the car seems to stop the sound. However it is not always the case. Also, I think it goes away faster if you start driving.
Wolrab
Thanks for clarification
Just a recap, if someone has similar issues. Problem: cyl 4&8 start misfiring after 40sec-1min when the car is cold. Nothing changed with new spark plugs and swapped coils. Solution: reset DME adaptation values (I used DIS, however INPA and other diagnostic software should work).
Back to the whistling noise
healthservices
Doesn't seem to be air pump related.
Here are 3 videos. First one: activate air pump with DIS, without engine running. Sounds ok to me.
2nd video. Start the car. There's a DIS screen that shows air pump status. It's active at first, you hear the whistling noise. At 0:20 it stops by itself, 0:33 starts again. 0:38 - 0:40 I pulled the dipstick out and you can hear the noise stopped. 0:48 the DIS shows that the air pump is off, but the noise is still there.
So the noise was on for 2 mins.
As much as I tried, I can't point where exactly the noise is coming from. Maybe because it's a high frequency noise, it seems that it is everywhere.
I wrote before that restarting the car seems to stop the sound. However it is not always the case. Also, I think it goes away faster if you start driving.
Wolrab
Thanks for clarification
07-01-2012, 05:50 AM
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Are your y pipes in good condition. I had the same noice on my car....unfortunately i got rid of the car before replacing it but thats what i assumed it was. It wont hurt to look into what a previous member posted earlier .