Hi there, new to the forum, bought an '04 Mazda3 Sport GT a week ago.

When I'm going at about 80km/h and above there is a loud rotational noise coming from the front wheels. I just got it back from the garage today and they had replaced the front rotors. However, as soon as I drove home, there it was again. Its fine during slow speeds but whenever you get up to a decent highway speed it just gets ridiculous. Its not a banging noise, sounds more like something is rubbing on something else. Tires seem new.
Any ideas?

Thanx.

 

Hmmmm? Well, is the suspension (and everything else) stock?
If the brakes were messed w/before you had the rotors done, could it be that someone removed/replaced the pads and did not replace/install the shims or retaining clips properly?

That's my best guess but here are a few others:
A bad CV joint is usually best heard @ slow speeds.
And a bad strut bearing does not sound rotational. However if the bearing has let go and caused the suspension to "drop" slightly it might be causing an out-of-alignment situation w/an axle or some other moving part of the drive train?
Or, it could be an outer axle bearing too??
I don't know for sure, Man, I'm just throwing it out there as possibilities to be looked into.

 

Agreed.

Some of the checks can be done to help a mechanic understand what needs to be done.
First you can try doing some hard left or right turns which may cause a clunking noise and/or an increase or decrease in the rubbing noise which would typically be a wheel bearing.
If you lift the car you can check a couple of things.

[ol][*]I believe that wheel bearings (or maybe it was outer CV joints) can be checked by grabbing the tire at the 12 and 6 o'clock positions and attempting to rock the tire. Any play what-so-ever would insinuate a bad wheel bearing (or joint if I'm wrong).[*](OPTIONAL) While you are there you can attempt the 3 and 9 o'clock positions on your tire to check your ball joints.[*](Easiest if you take off the tire) You can try moving the break pads physically with your hands on both sides and see if they have any play, which some cheap shim could fix if your bothered by the noise.
[/ol]I forget the way of figuring out the CV joints (inner or outer) other then by eliminating the other possibilities. It has been a while since my last car had made noises so I can not really remember everything.

Keeping in mind that my last car was a Volkswagen, working on things with the Mazda 3 could be different. But if it is a wheel bearing your stuck floating the bill for the mechanic to do it because the tools required to do drive line wheel bearings typically require a hydraulic press. Also, when you are replacing one, it is best to do both and it becomes ridiculously expensive to replace a $50 part with labor rates added in. As for the CV Joints, they are doable, they are just a pain in the butt.

 

I just replied to a similar post, if the sound intensifies and then goes away while the brakes are applied the problem is brake related (warped rotor, sticky caliper).

If the sound intensifies with a turn in one direction over the other its most likely the wheel bearing on the side the sound is emmenating from.

if it seems the extension/retraction of the suspension effects the sound get ready for a CV.

The bad news, two of the three options will cost you in the $300 to $500 range. Let us know how it turns out.

 

Oh one more thing, you can't replace the wheel bearing on its own...you have to replace the hub assymbly-only slightly more work than changing the brake rotors.