Car humming after a timing belt change?

I recently changed the timing belt in my car. Now there is a humming sound coming from the engine. What could it be? Thank you.
Car humming after a timing belt change?
timing belt rubbing, tensioner maybe damaged, pulley misaligned, maybe a loose bolt, waterpump? lots of things really. i would tear it back down to be sure its not something bad cause you dont want it to break!