[Mark963]

Newbie post - please be gentle.

After looking for 20 years, I recently bought a 2011 (2010 production) 328i XDrive. I've seen some videos suggesting that its odd whining noise (peaks around 1800rpm, tied to engine speed, not car speed) may be due to the power steering pump. So I was checking the fluid (CHF 11S) and it looks very milky/cloudy. I used a flashlight shining on the fluid to take the picture above - otherwise it just looks black.

Reading a bunch of threads on here, someone mentioned water from steam cleaning as causing the power steering fluid to go cloudy. The engine was unnaturally clean when I bought it.

My other thought is that this could be due to air getting mixed into the fluid from a leak near the pump. The reservoir looks full but maybe air leaks in a lot easier than fluid leaks out.

Is this normal for used fluid? I know it's transparent (and green) when new. Does this indicate some other repair is needed?

Thanks for reading,
Mark