Your Mazda millenia timing belt broke while driving do you need to replace your engine?

You just discovered how inconvenient it is to lose all power for some unknown reason out of the blue. But to answer your question - no, you do not need to replace the engine. It is not a interference motor. Meaning that the valves will not hit the piston tops as the valve train freewheels because the timing belt broke. Congratulation for diagnosing the problem, it took me a while before I figured it out when it happened to me - on a Toyota cressida.

If you have a timing belt it is a good idea to replace it when scheduled or u risk being stuck out who knows where. If the motor happens to be an interference motor - you will have had major engine damage, cannot be avoided. If it is a non-interference motor (There are reference books that will need you VIN number to say exactly what stock motor you have in the vehicle), there is a slight chance you might have damaged it, but more often than not it is just the inconvenience of the whole issue. Beware that some service shops will mislead you to scare you into a expensive service. I have assumed that we are talking about a 2.3 liter supercharged motor in your Millenia. Just look it up yourself at the library or online to be sure in your case.