Exactly what happened to mine !The gasket is leaking because the manifold has warped which has physically pulled the studs out of the head, yes it needs sorting as its will only get worse.
Nip the nuts up on the effect cylinder and see how long it is before it gets noisy again, might make a week if you are lucky.
Not a hard job, but you will need the manifold skimming and well worth doing the mods to stop it happening again.