2003 BMW 530I. Whistling sound while engine running. See attached video

[petes1997bmwz3]

I have a 2003 BMW 530i with 121k on it. Would like to have some expertise advice as to the whistling sound while the engine is running. See attached video: https://youtu.be/rF5jb3WF-ZU
I believe it's the crankcase ventilation valve but I would like some confirmation from others who may have experienced this. Furthermore, upon a cold start that you didn't hear in the video, the engine will make this metal slap sound 3 or 4 times and then disappear. When this occurs the engine will drop in rpms and then go right back up. Once the engine starts to warm up, this slap/bang sound disappears. I'm not sure if this would be related to the crankcase vent valve or a whole other problem. There are multiple misfire codes as well which kinda tells me that the crankcase vent valve has failed in some manner.

Please review the video and provide your thoughts.

[jclausen]

Or the disa valve

[MIKYZZ4]

I would smoke test to identify all intake leaks, which I suspect is the cause of the multiple misfires.
I would also remove belt, as a test, to confirm sounds are not also being generated by failed pulleys.

[petes1997bmwz3]

What exactly is the disa valve? Is it part of the crankcase vent kit?

[XAlt]

What exactly is the disa valve? Is it part of the crankcase vent kit?

DISA Valve is not part of the CCV. I'd just fix both.