Yeah.

 

Well the most common and easiest tell tale is a enormous amount of white smoke out the tail pipe's.. Water in your oil is another common symptom.. I'm sure there are others..

 

Compression and/or Leak-down test would probably be the most useful, but coolant entering the combustion chamber will cause white smoke as IllusionalTA stated above (-should be fairly obvious if you're burning coolant)...

 

Check for coolant in your oil and vice versa.