Low whistle and 'washing machine' sound while driving?

[jamesbeat]

I have a 2005 Liberty 3.7l with about 180k miles.

I recently noticed a new sound while driving. It's difficult to describe, but imagine the sound a washing machine makes, but very quiet, like the washing machine is in a different room with the door closed. The sound speeds up and slows down depending on driving speed.
There is also a low whistle that I noticed at the same time, though I am not sure if the two sounds are related. It's definitely a whistle, not a whine, almost like a low-pitched wind whistle.

I know this all sounds very vague, but the sounds are quite subtle and difficult to describe. It is not possible to tell exactly where they are coming from either, and driving with the windows open doesn't help, in fact they seem to get quieter.

I'm basically just looking for some advice on where to start looking. It's tempting to leave it a bit longer to see if it gets louder, but I know that's probably unwise.

I'm wondering if it's maybe the front driveshaft, as I know this is a weak point with this model. I had a liberty before, and had to replace the front driveshaft, but it was already making quite a loud sound by the time I owned it, so I don't know what it sounds like when the problem is just starting to happen.

Any ideas?

 

[sleazy rider]

Brakes worn? Could be the *swish* as the worn pads scrape the rotor.

 

[lfhoward]

My front wheel bearings died and needed replacing at around 180k.

The rear cv on the front driveshaft sounds more like chains dragging than a constant swish sound, when it starts to go. Also the grease boot disintegrates and the grease slings out by centrifugal force.

 

[jamesbeat]

Brakes worn? Could be the *swish* as the worn pads scrape the rotor.

Sorry, I should have mentioned that the noise still happens and is unchanged during braking. If it was worn brakes, stuck caliper, warped rotor etc, I would expect the nature of the sound to change during braking.

 

[jamesbeat]

My front wheel bearings died and needed replacing at around 180k.

The rear cv on the front driveshaft sounds more like chains dragging than a constant swish sound, when it starts to go. Also the grease boot disintegrates and the grease slings out by centrifugal force.

That 'chains dragging' description makes sense, since it's the bearings failing. That's not what it sounded like on my previous Liberty, but the driveshaft was already pretty far gone on that one.

I wouldn't call the sound a 'swish', it's more like a quiet 'wump wump wump wump' sound. Imagine a washing machine that has a slightly uneven load and is on a spin cycle.

Is it possible for the rear driveshaft or a differential to make a sound like this? I have heard a whining diff before, and it doesn't sound like that.

 

[KJowner]

Sounds like a wheel bearing to me, is it louder to one side? Time to jack it up and have a feel and listen at each wheel.
If its a rear you may well have oil come past the seal too as a good clue! Don't ignore it, a rear bearing will destroy the halfshaft.

 

[jamesbeat]

Sounds like a wheel bearing to me, is it louder to one side? Time to jack it up and have a feel and listen at each wheel.
If its a rear you may well have oil come past the seal too as a good clue! Don't ignore it, a rear bearing will destroy the halfshaft.

That's the thing - I can't tell where it's coming from. Can a wheel bearing make a 'whumpwhumpwhump' sound and also a low whistle?

 

[KJowner]

That's the thing - I can't tell where it's coming from. Can a wheel bearing make a 'whumpwhumpwhump' sound and also a low whistle?

It's usually a drone/growing noise, but noise is hard to describe!
I'd jack it up and check all the wheel bearings and have a good look at the tyres too, you may find some damage.
I have had a BMW with a whistle, that was a split in the breather, found it when I took the oil cap off with the engine running and it suddenly went quite!

 

[jamesbeat]

Yeah, I'm wondering if it could be tire noise. I did actually notice that it happened just after I inflated my tires, but I can't see any damage to them, and they are only about 18 months old (I also only drive about 5k miles/year) so I thought it was just a coincidence.

I have watched a few videos on how to tell if it's a wheel bearing, so I will try some of the methods shown and report back. One big thing seems to be that a bad bearing will get louder when side loaded during steering. I'm pretty sure this isn't happening, but that is one thing I will check.