burning coolant?

So i've got a 2000 ECHO that my mother threw at me to fix. It's engine had overheated and the whole car in general was poorly taken care of. So long story short I got a used engine that was "pomised" to have not more then 13,000 miles on it. the last reported mileage on the carfaz was 11,000 - so ok.

so i put it in, everything's pretty straight forward on that car, and i start her up.

She ran fine - sort of. The idle seemed like the timing was a bit off, but it didn't sound like anything else was wrong with it. except for the white smoke pluming out of my exhaust. So yeah, she's burnin' coolant. I disconnected the wires from the spark packs and i cranked the engine a few times and let her sit. No coolant was 'puddled' in the combustion chamber - i'm stooped. Where could it be leaking? Someone suggested the throttle body - but that makes no sense to me. would/could the throttle body leak? Does anybody know anything that might point me in the right direction?

The car runs FINE! But i'll get pulled over if i go driving in an echo smokin like a jet plane.