Power Steering - proper fluid level? Noise?

[XKxRome0ox]

so i heard loud whining noise from the engine bay on sunday morning after a cold start
figured it's the power steering fluid and/or pump
pulled over after a short drive and took the above video to capture the sound
it was louder when turning the steering wheel

the noise went away after driving about 12 miles on the freeway
and i haven't heard it again all week

checked the PS reservoir when the car was cold
but i'm not sure how much fluid the reservoir is supposed to have

it's too difficult to see in the video
there is a "line" that goes around the entire inner surface of the reservoir and the fluid was a little below that mark
and the color was greenish with some brown mixed in

is the ps fluid low?

2008 e90 M3
just passed 60k miles

should i just change the PS fluid? is it necessary or recommended to replace the reservoir?
does it sound like it could be something else?
oh and there is some play when i wiggle the PS reservoir. normal? should i try tightening it up?

[Redd]

There's a dipstick in the cap. Fluid should be at minimum mark when cold.

[XKxRome0ox]

Originally Posted by Redd

There's a dipstick in the cap. Fluid should be at minimum mark when cold.

ha
i'm a genius
i saw it but didn't even look at it

[XKxRome0ox]

ps fluid definitely seems too low
it barely touches the bottom tip of the "dipstick" attached to the cap

[BOOF-M3]

Originally Posted by XKxRome0ox

ps fluid definitely seems too low
it barely touches the bottom tip of the "dipstick" attached to the cap

It will quiet down immediately upon filling. Dealer has it in stock as do most all auto parts stores.

[Redd]

Don't overfill or it will just spray all over your engine bay when it heats up. The fluid should just touch the bottom mark of the dipstick with cold fluid and engine off.