E70 3.0 engine making a high pitched whine?

[bmwman528e]

My wife's 2007 BMW X5 3.0 just started randomly making a high pitched whining noise that is very annoying. It has 120k miles so we thought it was the electric water pump since they tend to fail around this mileage anyways and the noise almosts sounds electrical. We replaced the water pump per our Indy and the sound is still happening. My wife says when you accelerate the noise goes away. Any input or suggestions would be great. We love our car but can't stand driving it like this. Drivability is fine as of now.

[BMWjason]

Check your power steering fluid, is it really dirty? Does it sound like you hydraulic pump is cavitating? The filter in the reservoir may be clogged.

[bmwman528e]

We narrowed it down to the PVC valve. Not sure if you have to replace the whole valve cover or if you can replace it separately.

[pshovest]

Replace the CVV diaphragm.
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[bmwman528e]

Originally Posted by pshovest

Replace the CVV diaphragm.
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Thanks so much you just saved me $400 by not having to buy the whole valve cover!

[pshovest]

Originally Posted by bmwman528e

Thanks so much you just saved me $400 by not having to buy the whole valve cover!

I haven't seen anyone report on changing the diaphragm. So you'll have to tell us how it works out. I pulled my plugs and coils to look for reason for my cold start driveability issues. Nothing obviously wrong, no oil in plug wells or eccentric shaft sensor connector. Looks like you can change the CVV diaphragm w/o pulling the valve cover. Need a tool to pry up the cover. I think something like this will work.
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