My 2005 xc90 is making a strange noise. It sounds like the engine is revving, maybe in the wrong gear. But when you pop it into neutral while you driving the noise stays while the rpm drop. Sound is correlated with the speed. Faster speed more noise, slower speed less noise. Example: if you go down a hill and drop it into neutral the sound winds faster as the car speeds up. Sounds like it would if you dropped it into a lower gear to go down a hill, and the car started to go faster until it reached the max speed (but it is in neutral). Any help, I cannot take the car in for another week.....................

 

Maybe a front or rear wheel bearing is bad.

 

Would that sound like metallic grinding or could that sound lower in tone so that it could be mistaken for the engine.

 

A wheel bearing would make like a roaring noise.

 

The tires were just replaced a couple of months ago, is this something that they should have noticed when they changed the tires? Would this be covered under the warranty or no?

 

Maybe if they drove it over 35 MPH. Factory warranty yes should be covered.

 

I am experiencing a similar noise from my '04 T5 FWD with ~45000 miles. Seems to comming from the rear, at speeds above 30-35 mph, the tone is relative to speed, not as noticable when turning to the right (weight shift to left side, unloads right). My instincts point to right rear wheel bearing.

I first thought the noise was tire wear/balance related. No change after a balance & rotate, tread depth at 3/32" on original Michelin 4x4 Syncrones.

Any obvious signs/indicators of a failing wheel bearing? I don't have the ultrasonic and vibration monitoring gear like I am used to on industrial machinery. What type of bearings are used for fronts & rears?

Thanks!

 

I was able to easily replace both rear wheel bearing units in a few hours this past weekend. The roaring noise that I was experiencing is now gone.

The only difficulty I had was getting the rotors free from the hubs, but with the right pry bar and a whack with the rubber hammer I was successful.