Cooling System may have a air lock. You can remedy this problem possibly by removing the radiator cap, starting you engine and allowing the vehicle to reach it's operating temp. All air which is trapped will gradually work it's way out through the spout. Be sure to top up the system gradually, as you will loose some coolant during this procedure, also be sure to have something under you vehicle to catch the coolant that will be lost. Not doing this could cause an animal to possibly lick it up. I am sure you know coolant is poisonous.
G.Davis, August 2007
