My Mazda has just started making a loud roaring noise only when accelerating. It's OK when idling. Any ideas.

Used tires sometimes are used for a reason. Also make sure your brakes are releasing completely (especially the emergency brake)...sometimes over-tightening wheels on to the disc brakes can cause excessive noise.

No they don't always do that but I have found that a roaring noise could be from the tires and not the engine.

There is no way to estimate cost until you know the exact case of the noise. See the dealer for a test drive so a tech can listen to it.

Sounds like a bad wheel hub to me

You have a front wheel bearing that is making noise. Usually the one that is the problem is louder when turning in the opposite direction. If you turn right and noise gets loud then its your left bearing and if you turn left and the noise gets loud then its your right bearing. Understand that thats just a rule of thumb and that either bearing can make noise in either direction. Good luck!

Could be something jumping around in the exhaust. Is your catalytic conv in that area?

3 suggestions for you, you may need to check the tire pressure, get a tire alligment done, or you have a bad wheel bearing, usally a bad wheel bearing make's a loud roaring sound going down the road. I hope I have helped you.

I have a very loud squealing noise in my 2003 mazda mvp engine when i accelerate. We removed the belts which would eliminate belts as the problem. And that's that it. If anyone has any info please let me know.
Thank you

jack up front of car get hold of tyre an see if u get any play if u do u may get away with nipping them up a bit

Have you given the throttle body intake a good cleaning ?