Well...
Is the sound coming from the front? The middle? Or the back?
One thing that makes older Toyota's MUCH louder is that the fan clutch will start to go and basically be engaged all the time. The "engine" sounds a lot louder when that fan is blowing constantly. Though that would normally be reserved for a vehicle with more like 250k on it :/
But uh, you'll need to isolate the noise location a little bit more as a first step