whining/buzzing sound under hood--power steering?

[Whoknows]

Anyone know about power steering bearings. I think mine may be going bad. Now that summer is past and I don't need my loud AC everyday, I hear a rather loud whine/buzz that tracks exactly with RPM. It is loud enough to hear over engine and exhaust noise on take off and at 30-40mph. It is worse when driving slowly and turning. Fluid levels are fine, no leaks. I think it is the bearing. Anyone have experience with this or with changing out the bearing?

 

[drmorbius]

Can you feel this buzz in the steering wheel? How many miles on your truck? Was there ever a leak in the power steering? I have over 50K on mine and all noises are normal.

 

[sharp4runr]

What about when your stationary and at full lock left or right? Does it make noise then too?

 

[socky3850]

I have the same problem with my 4R. I have around 59K miles on my vehicle and have a whining sound that sounds similar to a power steering pump that is low on fluid. I can't feel anything in my steering though and have no warning lights on the dash. This has gotten progressively louder over the last 1K miles. I haven't yet tried to troubleshoot this yet with my stethescope so I don't know if it is the ps pump or the alternator or whatever. I suppose that this could also be a tensioner for the serpentine belt. If I figure this out, I'll post what I've found.

 

[JP4RNR]

This is the disadvantage of having one belt to drive all accessories as you cannot isolate which component being driven by the belt is acting up not to mention a single point of failure leaving you stranded should the belt break.

I think there is nothing wrong with having a minimum of 3 drive belts. One belt for the alternator and water pump. one belt for A/C and another belt for Power steering some "old school setups" should have remained

 

[Whoknows]

Thanks for the replies! In answer: I have 38K miles. I Cannot feel it in the steering wheel. Noticeable/worse, but not significantly, at full stop. It tracks with the amount of torque being used in steering (when your stopped and turn the wheel, you can hear it increase exactly with the turning). It also tracks with RPM, as mentioned. This is why I think it is isolated to the PS. Since I'm out of warranty, I'm thinking of downloading section of service manual and seeing what it takes to replace the ps bearing.

 

[shootmymime]

i think all u guys have newer 4runners... but does it happen when driving? or after u turn off the car?

does the new T4R have the charcol canister? there is a TSB on the canister for its noisy buzzing.... id check that...