I am getting a groaning noise (mainly above 50 miles per hour). I can't tell if it's tire noise or something else. Could a wheel bearing (front or rear) cause this. The tires are Nitto 555 with about 43k on them (but good tread).

Could alignment cause this? Tires are wearing relatively evenly. If I put the car in neutral (manual) on the highway and disengage the trans, it still makes the same noise so I'm guessing hubs/tires? I don't think it's the rear end. Help!!

 

Could be road noise.
Also... have you changed mufflers lately?
Might be drone from exhaust.

 

If the roar get progressively louder as you are on the freeway, then the most common case is wheel bearing, but oddly, its not suppose to go out on the given mileage you have provided.

I would check the tire pressure first, then replace the bearing.

 

I put the oe mufflers back on when I did the high flow cats and X - no drone at all - I wish I still had the other wheels and tires so I could swap temporarily

 

All tires are 32psi cold, I checked before this last trip. I would just do the bearings 1st but I don't feel like spending $400; maybe 2 rear, then 2 front later

 

more than likely its your tires...

 

I think you're right...

 

Try to identify which corner the noise is coming from. If it is coming from the front right, then swap your front tires from left to right. If it is coming from the rear, swap the rear tires left to right. See if the noise follows the tire. To check the wheel bearings, jack up the car and try to shake the tires to see if you can feel free play by holding the tire at 6 and 12.

 

I doubt that it's the tires.

I'd check wheel bearings/hubs first for play.
Then the drive shaft joints and especially the loop housing since it's a 2 piece part.
Lastly, the rear axle.

If it's related to drive shaft and close to $500 in repair, get a one piece aluminum and be done with that with a great upgrade to boot.

 

I have a humming -whirring noise periodically and can't find the prob. when it makes this noise I have went as far as putting car in neutral and turning off key so it's coating and still hear it. only have 30k miles and all wheel bearings feel tight. put new brakes all around still hear it after I drive about an hour. any Ideas? It resembles a large fan and minor whining sound.