Need help to diagnose Xantia wheel humming

[citroDane]

Hi guys,

For the past two three months I got a low frequency noise on my 99 Xantia (/ humming)
coming from either the front or the rear wheels. The reason I can’t figure out whether it’s
coming from the front or rear is because it’s in the “bass” frequency area. It sounds like a
propeller airplane flying at a distance, starts at around 70 km/h and doesn’t get too much
louder at a lot higher speeds.

I am thinking it could be:

1. The tires (all tires got some mileage on them but have 1/3-1/4 of the threads left)
2. One or more of the ball bearings (though I’d expect this to make the noise appear at speeds lower than 70 km/h and maybe get worse as the speed increases)
3. The exhaust (2.5 years old and looks good, so I almost didn’t want to mention this but anyway)

I would appreciate any hint that could help me properly diagnose & locate this problem.

Cheers,
Gabriel

[KP]

It will likely be a front wheel bearing. Does the noise change when you go round a long corner either left or right at all?

[citroDane]

Not that I can hear. As I mentioned it's not there below 70km/h which is most of my driving -in the city. Generally I haven't detected any dependency to steering left or right.
Are you saying the kind of noise I have described is most commonly connected to a wheel bearing?

[HDI Dave]

I had that on mine,only at speed,motorway etc.

Intermediate bearing

front right hand (OS,UK version) driveshaft iirc

Proper drone it was,like a washing machine!

You can't tell if it's from the front or the back,as it's near the middle /front ish, and the whole car humms!

[RichardW]

Worth running your hand around the rear tyres - they can develop a stepped profile on the inner edge which causes a humming noise. No idea why - I had one go like this. Mind you it was on the car when I bought it, and it was still there, humming away, when I sold the car 65k miles later. They do last and last tyres on the rear of Xantias!

[citroDane]

Hi Dave, Richard,

Thanks for your responses.

Dave, is there any way I can examine the intermediate bearing for wear (the way you can
do with wheel bearings by wobbling the wheels when jacked up)? And if it’s that, how
urgent is it to replace the bearing? I’m going on vacation next week and will be driving
a 1000 kms!

Richard, I’ll check the rear tires tomorrow. It’s right what you said about the rear tires lasting.
Mine have been there for more than 70 tkm. I guess they can do another 1000 km then!

Cheers,
Gabriel

[KP]

Worth running your hand around the rear tyres - they can develop a stepped profile on the inner edge which causes a humming noise. No idea why - I had one go like this. Mind you it was on the car when I bought it, and it was still there, humming away, when I sold the car 65k miles later. They do last and last tyres on the rear of Xantias!

Not unless you drive an Activa

The intermediate bearing is a good call as it wont change with cornering but with speed only and can be heard more when coasting out of gear.

If you can get it changed before you go then its worth changing as the time you need it and don't want it to fail is the time that it will fail, or it gets really really loud and noisey... had that on a 1.9td mk2 and before the car was scrapped it was very loud at speed!

[rory_perrett]

I've got the same thing, sounds a bit like turbo prop aircraft. I'm convinced it is from the offside rear. This is the wheel that is difficult to balance so I'm hoping its the tyre. Keep meaning to change it for the spare and see if it goes away.

[h2ocooler]

Only way to check it would be to prop the car up SAFELY and then using a screwdriver with the blade on the bearing housing and your ear on the handle get someone to spin the wheel and listen for a rumble.
Rob

[citroDane]

Hi KP, Rory, et al,

Thanks for your replies. I checked the rear tires as per Richard’s suggestion and sure enough they have developed a stepped profile on the inner edge so I guess we can’t rule them out as the culprit.
Given that my game plan is to change those and if the noise is still around after that to replace the intermediate (front) bearing.

How does that sound?

Rory, I'd appreciate it if you could speed up you plans to change your rear tire to see how it plays out –say do it today or tomorrow?!

Cheers,
Gabriel

[rory_perrett]

CitroDane

I've just changed the wheel and will check if the noise has gone when I hit the motorway tomorrow. I only notice it at speeds above about 45mph (70kmh) although it has been getting loader over the last 2 months or so.

I'll let you know.

If this doesn't fix it I might have to look at the bearing as it has now done 265,000 miles (424,000km) so it could be a suspect.

Rory

[rory_perrett]

Ok so I've changed the wheel and it hasn't made a lot (or any) difference.

Next stop rear wheel bearing. When I was changing the wheel I had a feel of and listen to the bearing. Seems to run smoothly and there is no sign of any movement or play but I'm still convinced that the noise is coming from the back.

[citroDane]

Hi fellas,

Computer problems took me off line but I'm all fine & back.

Like Rory I replaced the tires and the noise is still there. I also get the feeling (though no actual proof as yet) it’s coming from the rear end of the car.
The next step? Well I am not too sure.
The intermediate bearing sounds like a good place to take action. But I suppose I ought to check all the wheels (starting with the rear ones) for play first!?

I am a fairly good DIY guy but don’t have a lift and miss some tools (e.g. puller) to get on with the intermediate bearing myself. Apart from rumbling while steering left or right, is there any other health check to perform on that?

[kevino]

I know this oesn't help your predicament but as an aside did you know the rear bearings are the same for the xantia as they are for the bx !!!

[HDI Dave]

The intermediate bearing sounds like a good place to take action. But I suppose I ought to check all the wheels (starting with the rear ones) for play first!?

Ah,maybe not so then,you might be lucky,it might be the rear bearing, as KP said and my own experience - the intermediate doesn't seem to rumble on cornering..it just gets noisier the faster you go, ie 40mph onwards,till it's Bloody loud!