Hi, my question is what would cause a roaring sound that gets louder with speed? The car is a 99 camaro V6 5speed, I know this is not 3rd gen related but thought somebody might know. I don't know what to check, could it be the rear end or the driveshaft u joints, or maybe the front wheel bearing? This is my girlfriend's car, she said it sounds like its coming from the rear of the car but isn't sure. Any help at all would be appreciated, thanks. How would i check the rear and ujoints to see if they are bad?

 

Out of shape tyres can also cause the most horrendous noises, get them checked first as its easier than everything else.
Dont forget wheel bearings, jack up the car and give the wheels a spin.

To check the u\j on the proshaft [driveshaft] you can jack it, or do it car on the floor if your not huge, and just reach under, just put it in park, handbrake on, grab the shaft where it meets the diff, one hand on the prop, one on the flange attached to the diff,, there should be no movement as you twist it back and forth, any real play will be really obvious.
Theres a nice gash in my rear floorpan, where some dip**** of a previous owner let the the uj get so bad it snapped.
But ive heard them lots of times before they go, and diffs and props usually are accompanied by lots of vibes and a bit [or a lot] of body shake.
A wheel bearing when it starts eventually takes on a droning sound, similar to a swarm of bees in the boot [if its the rear] then eventually it sounds like an incoming B-17.

 

There's also the pinion bearing in the rear - this bearing is held with a large nut in the front of the rear, directly behind the drive shaft. I had a pinion bearing go bad and it roared, and louder with more speed. Not hard to replace, and cheap to do, just make sure you torque to specs when replacing the nut, or you'll crush the "crush sleeve". Better yet, get the pinion spacer to replace the crush sleeve.