What model of mazda do you have?
Year / Engine etc?
It is a 1999NB, 1.8 litre
Hi.there..sorry for the delay...
There should be gasket between the cam cover and the cylinder head..you shouldnt need any sealer - if the cam cover was leaking then normally its just the gasket..the cam cover shouldnt need replaced.unless its cracked for some reason..as long as the mating surfaces on the cam cover / top surface of the cylinder head is clean - new gasket fitted and the cam cover torqued down in spiral formation it should be sealed..if the oil leak is still happening at the front end of the engine..then checks need to be made the front end seals cam seal/botom crank oil seal/ oil pan gasket