Originally Posted by DukeSkywalker

Sounds like a head gasket or it could have sucked in a valve, or opposing cylinders that were top dead center at that time could have wacked the top of the valve and bent the stem leaving it partially open.
I dont know if its a turbo, but you could have done something to that from the over rev. It doesnt sound good though.
I hope it's nothing big and costly.
Cheers,
Duke