humming noise???

[kris2487]

hey all! i have an 04 nissan altima se. recently its been making a new noise. its a humming noise that seems to get most noticeable at about 45mph-55mph. i had a friend that said hers made a noise like that and it was bearings. had that checked and its not bearings. bought new tires because the humming sounds a lot like road noise and it was time for new tires. new tires on and still the noise. any ideas?

[EOrdonez3229]

when you hear this at these speeds, do you notice any shaking of the chassis and/or steering wheel?

[kris2487]

not at all. my dad says maybe a transmission module. i was thinking maybe something w/ the exhaust.

[Darius]

Exhaust noises won't vary with car speed. Its noise will be probably be rpm related. Rev it up in the driveway and see if it makes the sound at a particular rpm. If it doesn't do it in the driveway, take it out to 45-55mph and see if the noise changes when you let off the gas or not. If it doesn't vary with engine load, then it is not the exhaust.

If the car is only 4 years old, I highly doubt that the wheel bearings are bad. My 240 is 11 and I haven't had any issues with them.

About the transmission module, again I highly doubt it is bad. When was the last time you had the transmission fluid changed? Should probably do it every year or two. If you haven't done it, do it regardless of the noise issue.