RocketMouse

Hello all... it's PS Monday.... figured I'd start a clean thread as the others I found were old and/or didn't want to thread-jack either....

Sooo....
stats: 99 XJ, I6 4.0, auto trans.
I have this low noticable "humming" sound coming from the front, I've listened to all other bearings on pullies and all sound either good or definitely not the source of the noise. It may happen at higher rpms but engine and road noise may be masking it from me. I did recently replace the idler/tensioner pully thinking that could be it as I could tell the bearing was on its way out. I double checked and I do have the tension set correctly on it. Not slipping and not too tight either I believe. Cold is about a 1/4 turn on the belt, same as it was before.
I can only hear it when in the cab of the jeep, at idle.
Starting to think that it could possibly be the PS pump. But it's not making the typical "whinning" sounds of a dying pump, and fluid level seems to be consistant. When I turn the steering from side to side, no whinning, but a low "whooshing" kind of sound. Steering is light as I recently had the box replaced with a Redhead.
No leaks of any kind that I have been able to detect.
I'm just trying to be proactive and not reactive if it is something like the PS pump. I don't want it to granade on me.
This is a replacement PS pump put in about 2 years ago. I have had to replace the steering gear box a couple times because I rolled the dice and came up old snake-eyes with crap remans before doing what I should in the first place and fork over for a Redhead. So don't know if the leaking previous boxes could have prematurely started to fry my PS pump itself. I never let it run low or out of fluid though.
Any assistance would be greatly appreciated.
Cheers!

BlueRidgeMark

Interesting. I suppose it could be the bearing going out, which isn't the usual failure mode for a PS pump. I wouldn't worry about it grenading, though. I have never heard of that happening, and the worst thing that would happen is that it would be hard to steer until you got it fixed.

Have you got a mechanic's stethoscope? If not, get one! You will be amazed at what it will tell you. It is the best possible tool for a situation like yours.

RocketMouse

Hi BRM....
Yes, that is what I used to check all the pulley bearings under the hood. Wouldn't work on a vehicle without one.
I didn't hear anything on the PS pump pulley bearing that would say to me that it was anywhere near shot. What I meant by "granading"...is not that the PS pump unit itself would go off like a bomb....rather I don't want any paracidic (in-line) damage down the line to my recently installed (rather pricey) Redhead steering gear box.
I don't know if the noise I'm hearing from when I turn the wheel is abnormal or not. I don't hear the typical "whining or groaning" sounds of a PS pump that is starting to get tired and may soon fail. It's like a low "whooshing" sound as you hear the pump working.
I've tried to narrow down what the bleep this could be. I do have the AW4 and believe I've ruled out it being the TC as going through all the tests for one it seems to be functioning normally and I believe it shifts just how it should for an auto trans. solid but smooth shifts at the right points. Only think I get is a tiny movement when shifting from Park into Drive. But for all I know that could be a trans mount I have to crawl under and check. But even if so, I don't think it's what's causing the type of sound I'm hearing. I've worked on my own vehicles for decades and while not a professional, I do know a fair bit.
But honestly it sounds more engine bay related, and nothing else is making any noise...so that's why I'm eyeballing the PS pump. And don't believe it's anything internal in the motor either...she's only got 106k on the clock, was taken care of and holds excellent oil pressure 40psi at full op temp idle and about 60+ under load.

OldTires

My reman PS used to make weird noises too. It sounded like a very faint radio trying to find a signal. And the sound changed at different times, as it warmed up. I couldn't tell if the PS is new or reman. If reman, I would doubt it.

So if you are listening on the PS with the stethoscope and someone turns the wheels, can you hear?

RocketMouse

I just have me, myself, and I right now until I move to another state here soon. So unfortunately I can't perform that one. Would be interesting to know if it does change.

I'm trying to narrow things down.. I honestly don't know if that is the root cause, but I've been able to rule several other possiblities out at this point.

What exactly would I be listening for that would considered as "abnormal" noise from that test?

BlueRidgeMark

That's the hard part, sorting out normal from not. I think you just have to trust your instincts. If you could listen to a known good pump, that would sure help.

Hey, maybe that's an idea. We should ask members to record various components of their vehicles with a stethoscope, and upload the results with commentary. Then we could all get a bunch of vicarious experience.

RocketMouse

That's not a bad idea... maybe limit it to like a 10 second sound bite so it doesn't take too much of a hit on the server(s) for storage.
You could make an old Jeep game show... "Name that PITA can't figure it out sound" game.

But seriously...a database of known issue sounds/symptoms could come in really handy in helping to diagnose unfamiliar issues.