i have a koyo aluminum radiator with my stock cap on it. the cap never really fit fight from the start but i was told by a few shops that the stock cap would be fine. i don't think it's fine because i can smell antifreeze every time the car gets hot and so i think the coolant is getting out there. has anybody had any problems like this before. or does anybody know of a cap that will fit on the koyo 100% correct