ok heres the deal, bought a b18c1, 5spd tranny w/stage 3 clutch. when the car is idling there is a loud clanking and rattling noise coming from the engine bay. when i engage the clutch the noise goes away. after i shift and then accerlerate the car seems hesitant, also my 5th gear pops out while im on the highway. no grinds. can anyone help, or ideas?

 

Speechless here. Doesn't sound good. Sounds like transmission/clutch problems.