scoober steve

dont worry panic over its not the engine its the exhaust manifold Phew

just bought a 1998 xj8 3.2, at idle on the top right hand bank it started making a metalic whack noise every now and then and its making me panick sounds heavy but idle is smooth and silent otherwise. im scared it might be a broken cam i dont think theres any valve damage as it idles and runs to well for that and if the chain was slack im shore it would contine all the time but it only hapens say 2 or 3 times a min any ideas guys please.