1999 Audi A6 freeze plugs

Gonna need more than that to go on. Do you have a question?

Will i need a engine if the freeze plugs bad

Well, that's one way to solve it, but no, you just replace the core plug, (freeze plug). They usually leak due to corrosion so be sure you're replacing the antifreeze every two years. It's the water pump lubricant and corrosion inhibitor additives that wear out in about two years. The plugs can also pop out if the coolant is too high a percentage of water and it freezes, hence the name people call these plugs. If that happened, then yes, it could do serious damage to the engine. If the coolant is running out, I doubt it froze.