humming noise coming from somewhere in the car? help please :)

[Tom_90]

I have recently developed a deep humming sound in the car when i go above 40mph. I think its coming from the back but i know it's not the exhaust as the noise would change with revs and not speed.

I do have a sub in the boot so could it be a problem with the alternator? was just wondering if anybody had a similar problem and a solution for me?
Thanks

 

[Malky]

Wheel Bearing possibly?

 

[Anonymous]

Yeah i'd say wheel bearing is 1st thing to rule out!

 

[Gaz_]

hhhhhhhhhhhmmmmmmmmmmmmmmmmmmmmm? ()

If its a wheel bearing sometime when you load up the side with the fault it'll sound worse, or jack up the car and spin each wheel and check for play. Should be apparent which ones at fault

 

[Tom_90]

i though that but it was MOT'd last tues!

i'm going to disconnect the sub and go for a blast along the a52 and see what happens

 

[Malky]

i though that but it was MOT'd last tues!

i'm going to disconnect the sub and go for a blast along the a52 and see what happens

I think (maybe wrong) that unless they are really bad, they may not be picked up on an MOT

 

[Tom_90]

its not my sub, just went for a spin with it disconnected and still the noise, it seems worse at 45-55 mph, after that itgets quieter but its still there. wheel bearing?

 

[Malky]

I'd say so mate

 

[Tom_90]

anybody know if its a cheap and easy job?