Well it seems to me most people on this sight (Not All) usually give you the worst case scenario when it comes to car problems. I wouldn't tear that motor apart just yet. This could be something as easy as a Bad Vacuum Hose or Harmonic Balancer causing your problem. Highly doubt it's a Rod or Piston unless you were running your car a couple quarts low on oil or you've been racing the heck out of it & using nitrous
on those Hyper tech pistons which aren't nearly as strong as Forged Pistons.
If you smoke pull the Vacuum Line off your Master Cylinder for your brakes & blow a lot of smoke through it. If there's a leak you'll see the smoke come out where the leak is. Also, Look at the very bottom pulley on the front of your motor. If the Rubber ring in the pulley is coming out at all you probably have a bad Harmonic Balancer. You'll also see the motor kind of moving weird instead of nice & smooth.
Before I did any of this though I would buy a bottle of Sea Foam & put 1/2 in my gas tank & 1/2 in my oil to see if it helps. Maybe an injector is clogging up & not getting enough gas to that cylinder. After you check those things if it still has the problem pull the valve covers off & check for loose Rockers & bad springs. Loose Rocker not so bad....Broken Spring may or may not be a sign of a worse internal engine problem.
With that being said, I wouldn't tear that motor down till you know for sure the problem is internal.