128i pvc valve whistle, poor idle and power, ac on goes away

[texas128i]

So I wanted to check on testing the PCV performance of the 128i. It seems these are built into the valve cover on our N52. My engine has been acting up and when it does I hear a whistle with it. The idle goes bad and it acts like it is missing when I hear the whistle.

I tested the engine with it running normally by opening the oil cap while idling and I would say it was hard to open and then went to poor idle (which I understand can happen as things go lean). I have a valve cover gasket leak anyway and was about to replace that, but this issue has caused really poor idle and power 2 times. I thought it might be Vanos at first, but after more looking seems like PCV at 85k miles.

1 - Has anyone run into this behavior with the PCV. Any other tests to do to ensure this is the issue?

2 - any pointers to more cost affordable valve covers with pcv that worked out well?

Since I am about to replace the valve cover gasket, I want to get as much maintenance'd as I can while I am in there. Many seem to say the valve cover is worth replacing anyway at 85k.

Thanks.

[Bimmer-Bob]

I haven't heard of folks replacing entire valve covers before, unless they're cracked (which sometimes happens, given the plastic construction). If you have the valve cover off anyway, I would ABSOLUTELY change the eccentric shaft sensor and seal (which might actually be your main problem anyway). Also plan to change out the Valvetronic motor gasket, just because.

Have you pulled codes yet? No sense getting all in a tizzy prematurely.

[texas128i]

I checked for any codes with BlueDriver, all clean - nada. I would say the sound is very close to this when acting up:

https://www.youtube.com/watch?time_c...&v=DIMpIAkWeNI

So since I am going to get into it and replace a leaking valve cover gasket, I want to make the list of other things to be done. Right now that is:

- Valve Cover + gasket
- Eccentric shaft sensor gasket
- Valvetronic motor gasket
- Eccentric shaft sensor (still deciding)
- metal spark plug shafts/tube? Is this one time use?

Anything else while I am in the area (bolts, etc). I will wait on spark plugs and boots.

Thanks.