I have checked my coolant levels with the manual all in check. So far my guess is the old radiator cap had a bad rubber seel. And a new one should do the trick.Better descriptions will get better suggestions for you. A picture is even better. Check your hose clamps and make sure your coolant is not overfilled. Do not fill radiator to the very top. You need room in there for expansion once the engine is warmed up. If you over fill radiator it will puke out coolant once the motor is shut off. Fill radiator to top of tubes only.