Ok here goes. My eXTCy is two months old has about two cases through it. I run HPA with a QEV and Firebolt and my dwell is set to 17. I clean my gun after every day of play using the manufactures suggestions as outlined in the user guide using GR33SE etc.
Today I gassed up my gun in the house and I could hear a faint constent hiss of air as soon as I slowly turned the Asa. The air seams to be coming from the bolt. However after pulling five or six shots and it seems to go away. Should I be worried or is that normal?
Its definitely not normal. Did you try unscrewing the hpa tank and screwing it back in again? Did it start leaking again. If not, then the bolt probably just needed a few cycles to lube itself properly. If the leak persists, check the o rings on the bolt and bolt guide.
That has happened to me once when I first used my eXTCY. It is probably just the o-rings needing to re-lube themselves. Check all the blot and breach o-rings to make sure that they are in good form. Make sure you keep everything nicely lubed (which it sounds like you are doing). If the leak persists don't hesitate to contact gog to send it in for service. You should still have a warranty on the gun, and if there is anything wrong they will take care of it for you quickly.