How would i get rid of a head gasket leak? Im sealing up my new kit, because it had a bunch of airleaks. it doesnt have a huge airleak at the head, but it changes the idle speed slightly when i spray carb cleaner on there. ive got a brand new head gasket on there, so i dont know what else to do. maybe put a thin bead of high temp permatex rtv sealant on the metal head gasket?