zx3focus

iTrader: (1)

I have a ticking sound on the back cylinder on the passenger side. It is most apparent between 2k and 2500 rpm. Inside the car it sounds like an exhaust leak but my exhaust is all one peice and I have double checked everything. The manifolds are tight and the exhaust is tight at the collectors. If the motor is revved by hand at the throttle body, as the revs come down it sounds like something it ticking loud, like metal on metal. Car runs fine, pulls hard. What could this be? Lifter? I pulled off the valve cover and checked to see if the rockers were loose but they were fine. Springs look fine.