Hello
I have some questions for an 2000 Elantra 2.0 L. DOHC
How often should the timming belt should be repalced?
If the timming belt brokes or jumps a tooth what happen?
Is this engine a free wheeler or the valves will hit the pistons?

Every 60k miles it should be replaced.

If it breaks or something, I'm not exactly sure what will happen, but it definitely won't be good. You'll probably be looking at a new engine.