That really depends on the location of the roar.
front of vehicle could be the cooling fan, bad wheel bearings, worn engine bearings, aggressive tread in tires.
rear might be exhaust noise, aggressive tires, worn rear end.
You might also just have a plastic bag stuck under the car.
Remove the muffler
the wheel bearing on the vehicle will make a roaring noise when you accelerate the faster you go the louder it gets
If applicable, you may have a faulty (locked up) fan clutch.
Brakes
The compressor may have a locked rotor in the condenser causing the loud roaring noise. Another possibility is low refrigerant.
A Toyota RAV4 would make a loud noise while driving if a piece of hardware like the camshaft is damaged or something is caught in the drivetrain. This will result in noise and potentially costly repairs.
My car was making this noise when I started it up. the noise went away after driving for a while. turnd out I just needed more oil.
is it a stick shift? mine is a stick shift and it got alot quieter after i changed the transmission fluid... google it.
Bad fan clutch!!
need to know what causes my car to make a heavy noise when driving. i have changed both front bearings but have discovered the noise still exist. Could it be a problem with the drive axlel?
Hi. it could possibly be your electric thermo fan.They work when the engine is hot even when the vehicle is stopped
That is your bearings. You need to replace them.