Steering wheel whirring/humming sound

2013 V6 with 51k miles. Just started noticing a few days ago that when I turn the steering wheel left or right I hear a whirring/humming sound. Most noticeable when I'm turning at a standstill, but still noticeable when I'm moving. Anyone have any ideas? thanks in advance.

 

fluid level ok?

 

That was really unnerving. I couldn't imagine it would be the fluid level as I just topped it off about a month ago (just for the heck of it, as I was topping off the brake fluid as well, and it didn't require much at all). I just checked and I could hardly see fluid from outside the container. I've filled it, don't see any leaks. Do I need to be concerned about air in the system, in the same way air in the brake system would be a concern?

 

if its excessively foamy yes...it means theres air coming in somewhere. Id check your lines for leaks and also your check your fittings maybe something is loose.

 

If it steers ok without any hiccups then I think you are ok topping it off. There will be a little bubbles in the fluid but it shouldnt be extreme.

 

Did you top it off with brake fluid? I hope not.

You have a 2013 and it seems you have topped it off three times. I have a 2012 and have never added fluid to mine, or my wife's 2010 Highlander. To be honest I have never had to add power steering fluid unless there was a leak.

 

No, it was power steering fluid I used and it was the only time I've topped it off. Where did you get the impression I've topped it off three times?

 

I did misread your post, but from your post above which I have underlined and bolded it looks like you filled it twice. Once a month ago and then again presently.

It appears you have a leak somewhere. And if you ran the supply empty you may have worn the power steering pump.

 

Hopefully your steering joint isn't failing, it's pretty common. There was a clock spring recall, not sure if that could break and cause that.