I have a busted stud, notm until engine is reeally wamre up does it seal almost completely. can hear it cracking back as it cools down after you have turned off the car. You can feel it, and see it on your boost gauge, epecially after start up on cold engine, even reving to 5 gradn- no boost, after a few mins you start getting boost as the manifold seals up. Getting mine fixed soon, havent been quoted nearly as much as soem fo you though