2005 MCS 6spd manual....

Ok I'm hearing a noise from the front end and mainly the passenger side. It sounds rotational, speed dependent, and is worst between 30-45mph but then gets quieter when I go faster than that. It makes no difference what gear or what rpms. It happens whether I'm braking or not, accelerating or decelerating. It's pronounced enough that I can feel a little vibration in the floor from it. It stops when I stop rolling.
It sounds a LOT like tire noise (like a chopped tire due to bad alignment) but it isn't. Yes, I've rotated tires and the noise sounds exactly the same. I inspected the tires and found no visible problems. The CV boots look to be in good shape with no evidence of leaking or cracks so I don't think its a cv joint.
But, I did find oil on the passenger side around the oil pan gasket area (which is also in the same area of the passenger side axle. I did install a 17% pulley a couple of weeks ago but surely that small amount of added power wouldn't take out an axle, would it?!? Any advice would be GREATLY appreciated!

 

Stupid question, but did you check the underneath of the car for anything that's snagged, or perhaps some dragging part?

You say it's speed dependent.

 

Your description makes it sound like wheel bearing failure... usually it will also get quieter if you turn the steering wheel one direction (while moving) and quieter the other direction... this diagnosis is especially convincing if this noise has gotten steadily louder over the last few hundred miles, and towards the end gets very VERY LOUD... Wheel bearings sometimes develop flat spots on the roller bearings and when the wheel turns on the spindle, the ridges formed by the flat spots make that noise...

That is what I would look at it being, but there may be more that know more about diagnosing a mini in-particular... usually this applies to most any car.

Good luck.

 

Maybe control arm bushing? My car had the same roaring noise, most noticeable at around 40 mph. At highway speeds, I'm not sure if it was any quieter, or whether the wind and engine noise just drowned it out a bit. My mechanic, who is a mini specialist, told me the control arm bushings are a common problem with the mini. He replaced mine with polyurethane ones that won't go bad again.

 

Another reason why I bring up the lower control arm bushing is because you mentioned it sounded like the tire was making the noise. In my case, it was the tire making the noise. The way my mechanic described it was because the control arm bushing was broken, the wheel was wobbling. So obviously switching the tires would not make a difference. If you let that go on, your front tires will wear out unevenly very fast.

I'm no mechanic, though, so get it checked!

 

I would agree with pilotguy1050 on this. Best way to test this theory is to do a lane change test. Get it up to the speed where it makes the most noise and change lanes. I think left to right will unload the passenger side but as I sit at my desk I'm not sure . If an abrupt lane change makes that noise go away while the passenger side of the car is unloaded... it's the wheel bearing.

If you have a basic set of tools and are mechanically inclined enough to do a brake job, a wheel bearing replacement should be no problem. You will need a 32mm socket (1.25 inch will work too) and a breaker bar with a cheater pipe to break the axle nut loose. An impact gun makes it super easy. Good luck.

 

another way to test for wheel bearing failure would be to jack up the car and spin the wheel by hand to see if the wheel spins nice and smooth or if it feels rough when spinning. You can get a good idea of what a good bearing is supposed to feel like by spinning another wheel that isn't making the noise.