High pitched squeal/"tea kettle" noise, only when moving

[MilenniumExplorer]

Hey all. I've been chasing this particular noise for some time now and I'm kind of at a loss now.
My 2000 XLS, with the OHV, has been making a high-pitched rotational squeal (more of a scream really) that starts out as a mechanical type growl, and increases in pitch as I speed up, when moving. Looking through the threads here, I saw some saying it could be a wheel bearing going out, others saying it could be a camshaft position sensor or a valve on the firewall. Since it only happens when I'm driving, it must be something in the axles, right?
In the time my truck has made this noise, the front wheel bearing on the driver's side actually did go out. So I had it fixed this week, and the noise seems quieter but is still there. Additionally I had the front driver's ball joint and tie rod (which I know won't make rotational noises) replaced. So what else can it be? The sound is difficult to place while moving but still seems to come from my left side, so is it possibly just the rear bearing? I've got a very slow rear diff leak which I plan on fixing soon, could it be that instead?
It still feels most likely to simply be the rear bearing, but I just wonder if there isn't anything else that could be causing this.

 

[Mbrooks420]

The camshaft position sensor moves 100% of the time. It’s not that. If one wheel bearing improved it, it’s probably the other one. Don’t but the cheap ones, or you’ll be doing them again next year.

 

[C420sailor]

Timken or SKF for the win (bearings)

Is it a constant squeal, or does it pulse?

How are your brakes? If you brake, does it change?

Does turning or changing lanes make it better or worse? Does it seem to get better or worse under load (accelerating)?

Is it better or worse in 4HI?

 

[hondaslave1342]

Hey all. I've been chasing this particular noise for some time now and I'm kind of at a loss now.
My 2000 XLS, with the OHV, has been making a high-pitched rotational squeal (more of a scream really) that starts out as a mechanical type growl, and increases in pitch as I speed up, when moving. Looking through the threads here, I saw some saying it could be a wheel bearing going out, others saying it could be a camshaft position sensor or a valve on the firewall. Since it only happens when I'm driving, it must be something in the axles, right?
In the time my truck has made this noise, the front wheel bearing on the driver's side actually did go out. So I had it fixed this week, and the noise seems quieter but is still there. Additionally I had the front driver's ball joint and tie rod (which I know won't make rotational noises) replaced. So what else can it be? The sound is difficult to place while moving but still seems to come from my left side, so is it possibly just the rear bearing? I've got a very slow rear diff leak which I plan on fixing soon, could it be that instead?
It still feels most likely to simply be the rear bearing, but I just wonder if there isn't anything else that could be causing this.

Try jacking up one tire at a time and spinning it to see if you duplicate the noise

 

[MilenniumExplorer]

Timken or SKF for the win (bearings)

Is it a constant squeal, or does it pulse?

How are your brakes? If you brake, does it change?

Does turning or changing lanes make it better or worse? Does it seem to get better or worse under load (accelerating)?

Is it better or worse in 4HI?

It seems to be basically constant. Sometimes, on cold days, it doesn't occur until I've been driving a little, air temp seems to have an effect.
Brakes are fresh. But when I brake the sound does change a bit: going from road to parking lot speed the sound's pitch changes and when fully halting it slows and then turns back to mechanical whining and then it just sounds like... a turbine spinning down? I suppose. It's a sound I'd generally associate with low brake pads but since they're new and so are the rotors, it isn't.
Turning or changing lanes, no real effect. I suppose moving to the driver's side quickly makes the sound "lurch" but that's it.
As for 4WD I haven't used it in some time, so can't tell you.


I agree with MBrooks' assessment, that the one bearing helping indicates the other but right now I can't shell out for another $450 bearing job at a garage, and I live in an apartment that restricts vehicle work, so it's kind of bad news in that sense.

 

[C420sailor]

Then I’d just bring it to a reputable shop and have them diagnose it. That way, if they change the wrong part, it’s on them.

 

[hondaslave1342]

It seems to be basically constant. Sometimes, on cold days, it doesn't occur until I've been driving a little, air temp seems to have an effect.
Brakes are fresh. But when I brake the sound does change a bit: going from road to parking lot speed the sound's pitch changes and when fully halting it slows and then turns back to mechanical whining and then it just sounds like... a turbine spinning down? I suppose. It's a sound I'd generally associate with low brake pads but since they're new and so are the rotors, it isn't.
Turning or changing lanes, no real effect. I suppose moving to the driver's side quickly makes the sound "lurch" but that's it.
As for 4WD I haven't used it in some time, so can't tell you.


I agree with MBrooks' assessment, that the one bearing helping indicates the other but right now I can't shell out for another $450 bearing job at a garage, and I live in an apartment that restricts vehicle work, so it's kind of bad news in that sense.

Take your tool box to a Walmart parking

It seems to be basically constant. Sometimes, on cold days, it doesn't occur until I've been driving a little, air temp seems to have an effect.
Brakes are fresh. But when I brake the sound does change a bit: going from road to parking lot speed the sound's pitch changes and when fully halting it slows and then turns back to mechanical whining and then it just sounds like... a turbine spinning down? I suppose. It's a sound I'd generally associate with low brake pads but since they're new and so are the rotors, it isn't.
Turning or changing lanes, no real effect. I suppose moving to the driver's side quickly makes the sound "lurch" but that's it.
As for 4WD I haven't used it in some time, so can't tell you.


I agree with MBrooks' assessment, that the one bearing helping indicates the other but right now I can't shell out for another $450 bearing job at a garage, and I live in an apartment that restricts vehicle work, so it's kind of bad news in that sense.

Have you considered it being your torque converter. They whine and match rpm under acceleration and decrease while braking. In park revv it up and see if whine becomes high pitched

 

[allmyEXes]

I'm hearing a similar sound in my '97 Blue 4.0 SOHC 2wd. It is a rotational sound which has me thinking an internal transmission sound or maybe differential. I know it is not the engine because the pitch increases with road speed and not engine RPMs. Yesterday I was hearing a squirting sound at very low rolling speed. I'm pointing more towards the automatic transmission. I think our transmissions are in the same family. I'll know if something suddenly gives out. I'll let you know.

 

[hondaslave1342]

I'm hearing a similar sound in my '97 Blue 4.0 SOHC 2wd. It is a rotational sound which has me thinking an internal transmission sound or maybe differential. I know it is not the engine because the pitch increases with road speed and not engine RPMs. Yesterday I was hearing a squirting sound at very low rolling speed. I'm pointing more towards the automatic transmission. I think our transmissions are in the same family. I'll know if something suddenly gives out. I'll let you know.

Torque converter

 

[J$hort]

I'm just going to throw this out there. Was experiencing the same type of sound on my 95 Explorer Sport with manual transmission, so no torque converter and I had recently changed hubs. The tea kettle sound was like a pulsating sound and was coming from left front. Finally went away after I refilled the power steering pump. Fluid was very low and I know these are prone to leaking. So, possible there. My noise was happening even when not moving. Just thought I would mention it for good measure.

 

[Dlojack]

Hey all. I've been chasing this particular noise for some time now and I'm kind of at a loss now.
My 2000 XLS, with the OHV, has been making a high-pitched rotational squeal (more of a scream really) that starts out as a mechanical type growl, and increases in pitch as I speed up, when moving. Looking through the threads here, I saw some saying it could be a wheel bearing going out, others saying it could be a camshaft position sensor or a valve on the firewall. Since it only happens when I'm driving, it must be something in the axles, right?
In the time my truck has made this noise, the front wheel bearing on the driver's side actually did go out. So I had it fixed this week, and the noise seems quieter but is still there. Additionally I had the front driver's ball joint and tie rod (which I know won't make rotational noises) replaced. So what else can it be? The sound is difficult to place while moving but still seems to come from my left side, so is it possibly just the rear bearing? I've got a very slow rear diff leak which I plan on fixing soon, could it be that instead?
It still feels most likely to simply be the rear bearing, but I just wonder if there isn't anything else that could be causing this.

I have a 5.0 and had the same problem for years I couldn’t find the noise it only happened sometimes when I drove it hard or up in the mountains it started throwing different codes for miss fire and cam positioning sensor I had put new plugs new wires new coil’s and had changed the sensor and after all this I was randomly throwing these codes I had bought the truck used with 240,000 miles on it so I needed those parts anyway it turned out to be the cam synchronizing shaft there’s a little bearings in there that start going bad and start whining under severe load or at high speeds when I change that the problem went away oh and it didn’t always Throw codes it wouldn’t make the noise without throwing codes it would usually only throw the engine light on when I was doing 70 miles an hour up a mountainWhen I took it apart the bearings obviously lose a lot looser than the new Cam shaft synchronizer the part was only $150 And pretty easy to changeYou can find videos on YouTube about this problem you need a sharpie and some basic tools to change it

 

[MilenniumExplorer]

Bumping this thread just to say that I finally figured out the issue. This after the front driver's bearing going out a few days after posting. When it was replaced the drive was obviously better but the sound never really faded. So after some more research and the noise not stopping, I returned to my mechanic and in the end, the noise was coming from my front passenger's hub lock nut. It had become loose, was re-torqued, and the noise has totally disappeared, much to my relief! So anyone with a mysterious, abnormal squeal from the suspension should definitely doublecheck their lock nuts before doing something more extensive.