Observing Piston to Valve Relationship

OBSERVING PISTON TO VALVE RELATIONSHIP

NOTE: This procedure is meant to place the engine in a safe condition to prevent valve damage (or further valve damage) if the timing belt is broken or you are unsure of the current crankshaft/camshaft relationship.




Remove Valve Cover
This will allow your to observe the position of the valves. Each valve is opened as the lobe on the camshaft rotates around and contacts the rocker and pushes the the valve downward against the spring pressure.




Remove Spark Plugs and Observe Pistons
After removing all 4 spark plugs, rotate the crankshaft until #1 piston is moving upwards, midway through its stroke. View all pistons through the spark plug holes and verify that no piston is at or near top dead center.

CAUTION: Never rotate the crankshaft so that a piston reaches top dead center while its associated valves are at or near their fully open position. Carefully observe valve and piston positions and if necessary alternately rotate the camshaft and crankshaft.