First off, check to make sure timing didn't jump. Take off the upper timing cover to line up the timing marks. The cam dowels should be at 12 o'clock and the notches on the cam gears should line up in the center. Then look down towards the crank pulley, theres a notch cut out on it, and right next to it, the plastic cover should have a tab sticking off it with some marks. It will say "10", "5", and "T". Make sure that notch is on that "T". If not that sound could be valves tapping pistons. I'll try to find pictures.