warped brake discs?

[e30lou]

hi everyone. i've had this strange noise when i'm driving and my initial thoughts were maybe one of the brake discs is warped.....it's hard to describe the sound but its like a warbling type sound if that makes any sense the sound gets more repetitive as i drive faster but eventually goes away when i start getting up to around 50-60mph

any thoughts appreciated

[Rtaylor2208]

Sounds like a wheel bearing to me, can you tell if its comming from the front or rear.

[suedenim]

Wheel bearing?
You should feel vibration through the brake pedal when applying light pressure if the disc is warped.

[e30lou]

Thanks, must be a bearing then as there's no vibration when applying brakes. Can't really tell where the sounds coming from. Could I do a check by jacking up the car and feeling for any movement from the wheels?

[suedenim]

Yes, holding the wheel at 3-9, 12-6 o'clock positions. Be sure to support on axle stands.

[clipper]

Yes, holding the wheel at 3-9, 12-6 o'clock positions. Be sure to support on axle stands.

IMHO the bearing needs to get quite bad before you can feel it like that.

My wheel bearing started with an odd noise which was tricky to trace and describe, but over a few months (about 2000kms) it got "bad" enough to be sure which bearing it was.
Changed it a few weeks ago and no worries.

If you dont want to play the waiting game I reckon the noise of the bearing makes as you spin the wheel will give a better clue as to which whel it is, assuming its a front.

Does the noise go away when you corner in one particular direction?

[mrLEE30]

As above wheel bearings can be hard to find, if there is no play when the wheel off the ground I would just keep using it until the noise gets louder up to the point you are sure which end the noise comes from, personally unless you are really low on funds I would replace left and right as a pair. Fronts are DIY with basic tools, rears are harder and best done with a hydraulic press after removing the trailing arm.

[clipper]

I would replace left and right as a pair.

I asked on here if I should o the pair regardless and loads of people (IIRC BrianMoooore included) said why the hell would I change the one which isn't broken !!!!

[mrLEE30]

my logic is if one is worn then the other is not far behind so whlie you have the tools and time to do one you may as well do two (plus most garages will not charge double for two), more saving when you consider driving to get the parts etc etc, so whilst i would not normally suggest brian is wrong i would change both if i had time/funds

but dont confuse this with me saying you must change both!

If it were me i would inspect the opposite side, if both bearings are by same manufacturer and appear in the same condition then i would consdier changing both, if one side is SKF the other FAG bearings for example then in the past one has likely been changed, in this case if it feel fine then no i would not change it....secondly if you car will be with you for years i would change both irregardless, if you may sell/scrap the car in the coming year i would not bother!!

Two lines of thought:

if it aint broke done fix it
prevention is better than cure

so over to you!

[e30lou]

thanks everyone for all the replies. will check it as soon as i get back to my place, which incidentally is 150 miles away which shouldn't cause too much of an issue should it?

mtLEE30 - the car is definitely a keeper so I'll consider doing both