Our 182 is overheating.We top up the water regularly and there is no loss of water when it is stood still overnight for example.Upon driving,water is getting lost somewhere and causing the engine to overheat. First thought was head gasket but having looked at oil filler cap it's perfectly normal...no residue at all. Can anyone suggest anything else it might be ? Can it be head problems without creating creamy mixture on oil cap ?? Any suggestions would be appreciated.:S