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Squealing/Whistling noise from 2008 BMW 328i

74190 Views 25 Replies 13 Participants Last post by  Ramrunner
Hopefully someone can assist with where the noise is coming from.

So here is the story.
On Friday I went to BP to get gas and my car did not full up all the way it stopped right under full.
So I went home.
I came back out to go to the store and started the car and it stalled... took 2 starts to start.
The CEL light is on.
I went to Autozone and got code read.
P0171 and P0174 Bank 1 and 2 too lean.
Also Misfire on cylinder 2.
I changed all the spark plugs and got code reset and then go misfire on cylinder 2. I then changed the coil pack and the code has cleared.
When I am accelerating when driving I hear a whistle sound from the passenger side of the car. I cannot seem to find where the sound is coming from.
It stops sometimes and starts again.

Also when starting car in the morning the engine shakes also happens when i put the car in park.

Here is the video of the sound
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I had similar symptoms, turned out to be a cracked oil filler cap! I was thinking that it was unlikely that it could be that simple but it was.
My engine light came on and off, it ran rough at low RPM and stalled when I came to a stop. It also showed as running lean.
Might have a leak, intake. Or, exhaust, but maybe not if misfires.

Autozone's for young players - to read real codes, including BMW proprietary, hidden, and shadow codes, you gotta move UP!

.
Hopefully someone can assist with where the noise is coming from.
added video sorry guys.
I have a buddy with one of those, he is out of town so when he gets back I am going to have him read it.

The car runs just under low rpm the car can stall. It stumbles and the whistling sound happens when i accelerate and let go of gas i hear it louder but it is their all the time mainly. I took apart intake and no cracks their. misfires are gone and sound is still here. Need to check exhaust and pipes below. sound comes from front passenger side.
Might have a leak, intake. Or, exhaust, but maybe not if misfires.

Autozone's for young players - to read real codes, including BMW proprietary, hidden, and shadow codes, you gotta move UP!

.
Check the belt?

Sounds like something's rotating....

.
Here are 2 more videos.
I have 07 328i Made the same noise just not as loud as yours!
Well i brought mine to the shop Other than a oil leak they couldnt find anything with the sound because it wasnt doing it... go in a few days later they said my exact car was there with the problem (the whistling) just happening all the time, it hasnt happen to me in 4 weeks now idk if it has something to do with oil leak cuz its running fine now Other than still a rough idle on warm start sometimes they couldnt figure that out, all i know is they said its a $900 fix some value, forgot sorry
07 328xi coupe -same problem

Silentus, what was the solution to that noise? I have the exact same problem, and it comes and goes.
Ok when this happens pop hood open and try to open oil cap if you can't open or has a lot of pressure most likely crankcase vent value, mine does it once in a while ill end up changing it sometime!
Silentus, what was the solution to that noise? I have the exact same problem, and it comes and goes.
Thanks. I opened the oil cap and heard some brief hissing. And the whistling noise has not happened since then. I still notice that my idle drops back and forth from 600 - 400 RPM sometimes. Is that crankcase vent valve something I should get replaced right away? Have you gotten yours done since then?
Ok when this happens pop hood open and try to open oil cap if you can't open or has a lot of pressure most likely crankcase vent value, mine does it once in a while ill end up changing it sometime!
did you check your gas cap? since it happened right after you filled up, maybe your gas cap is not secured correctly
or maybe you got some bad gas with water in it
bringing this one back from the dead...

My wife's 2007 328i started making this same sound and it's accompanied by rough idle and an occasional stall. Has anybody come up with a definite solution?
Hello All,

I just went through this. If there is a large vacuum present making it difficult to remove oil cap this is a crankcase breather problem. There is so much vacuum being created that it is sucking air through the main seals creating the whistle. Not positive it is through the main seals but somewhere creating whistle. This requires a replacement of the valve cover because the CC breather vent is integrated in the cover. If you do the Valve Cover yourself make sure you have a good torque wrench and if you go over the torque specs don't back off the bolts or you will have to replace them. Great video to understand what I mean:

This was my original thread, scroll to bottom for results: http://www.bimmerfest.com/forums/showthread.php?t=745998
Thanks. Based on your pictures, I wonder if this is symptomatic of sludge buildup? And if so, would cleaning the engine (de-sludging?) restore the CCV to operating condition?

These are really just rhetorical questions on my part, but I would welcome other's thoughts or comments.
Hello All,

I just went through this. If there is a large vacuum present making it difficult to remove oil cap this is a crankcase breather problem. There is so much vacuum being created that it is sucking air through the main seals creating the whistle. Not positive it is through the main seals but somewhere creating whistle. This requires a replacement of the valve cover because the CC breather vent is integrated in the cover. If you do the Valve Cover yourself make sure you have a good torque wrench and if you go over the torque specs don't back off the bolts or you will have to replace them. Great video to understand what I mean:

This was my original thread, scroll to bottom for results: http://www.bimmerfest.com/forums/showthread.php?t=745998
Yeah definitely a sludge issue. I've seen mixed feelings on additive to clean engine etc regarding seals and such. I did notice the sludge dissolves with new oil so short interval oil changes may help. I also noticed after replacing the valve cover, it sucked up about a quart of oil. That leads me to believe oil stays up there, turns to sludge and then starts falling off and accumulating on the head until new oil washes it away. Just speculation though.

Some thought pulling the cover and doing a cleaning might work too, for me it was just easier to replace the cover.
My sister is having the same issue (whistling, occasional rough idle, CEL on) on her 07 328i. Definitely going to replace the valve cover per your recommendation. However, in that other thread you linked to, you mentioned you were still getting the P0012 code. Did it end up resolving itself? She took the car to a local shop and wanted to just replace the 6 ignition coils and plugs per the CEL code pulled, but i think he's wrong. Thoughts??
Yeah definitely a sludge issue. I've seen mixed feelings on additive to clean engine etc regarding seals and such. I did notice the sludge dissolves with new oil so short interval oil changes may help. I also noticed after replacing the valve cover, it sucked up about a quart of oil. That leads me to believe oil stays up there, turns to sludge and then starts falling off and accumulating on the head until new oil washes it away. Just speculation though.

Some thought pulling the cover and doing a cleaning might work too, for me it was just easier to replace the cover.
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