I was driving my car close to home when a Stop, Check Coolant warning light appeared. I arrived home ok. When the engine cooled down i checked the coolant level on the expansion tank and the coolant level was just below Min. I filled the coolant to just below the Max.I took the car for a drive until the engine reached its normal driving temperature and when the car reached 10 miles the Stop, Check Coolant warning light appeared. I stopped the car and checked the coolant expansion tank and it was still just below Max. I checked around the engine and the rubber hoses for any water leaking and i could not find any water leaks. The engine has always stayed at normal driving temperature. The only thing that i can think of is maybe there is an airlock somewhere in the radiator system as the coolant level was below Min before i topped it up. Any help would be great as my car knowledge is minimal. Thanks.