Step 1: Remove Crap in the way of the rear VC
Step 2: Remove Rear VC
Step 3: Unbolt the ICM and crank the motor over and see if there is any strange movement on the Intake or Exhaust valves on the cylinder closet to the drivers side...or the far right if your standing in the front of the car...also...check the rocker arm/bolt to see if one or the other is loose.
Step 4: Report your findings and have a few burz