We can't help you identify which is the cause. Generally overheating would occur due to coolant losses but if obverheating had occurred due to faults in the cooling system, it can result in cooant being discharged through recovery tank.
Is the recovery tank empty?
Have you checked for leaks in the cooling system?
Please consider a to help us answer more questions.
Saturday, November 24th, 2012 AT 1:17 PM