Easy way to check man, let it get to running temperature from cold (make sure the coolant is full before you start), id say 15-20 minutes. Cut the car off, pull the #1 spark plug wire and plug out and put a mirror (a makeup style compact one will work) over the hole for 20-30 seconds.if you pull it off and theres condensation on the mirror, then you got coolant leakage in that cylinder. put the plug back in, and go down the line making sure to only have 1 plug out at a time, and doing it in a timely manner.