Loose RV8 head stud

[number 7]

Just returned from a European trackday with what I thought was a blown exhaust manifold or gasket. Further investigation revealed that gas was escaping from the n/s head, so stripped things down today. Got as far as cracking 6 of the 10 nuts (ARP studs used)and when I came to the 7th., it was not even finger tight. This was the stud closest to the leak. The first thing is I'm a bit puzzled how one can have slackened, albeit c. 5 yrs. from when they were fitted by the garage. Is this possible? Can the engine have run for all this time with one loose and no symptoms? Secondly, should I even contemplate just torquing it all back up again without taking the head off completely?

It didn't overheat, and only possibly showed slight presurisation of the coolant when attempting to find the gas leak - i.e. not even hot.

Any thoughts guys?

7.

[Boosted LS1]

The studs are only supposed to be installed hand tight in the first place. Then the torque on the nut nut pull's everything into tension. Maybe somebody forgot to torque that nut. Seeing as you've got this far I'd certainly change the gasket and retorque it again.

Boosted.

[number 7]

Pulled the head. Gasket completely shot next to the loose nut. Ho hum.

7.