The valve clearance generally does not need adjustment unless valvetrain components have been replaced, a valve job has been performed, or if the valves are noisy. The simplest check for proper valve adjustment is to listen carefully to the engine running with the hood open; if the valvetrain is noisy, adjustment is necessary. The valve clearance must be checked and adjusted with the engine cold. To begin, remove the
Valve Covers and rotate the crankshaft clockwise to position the number 1 piston at TDC. In this position, check and, if necessary, adjust the valves for cylinder number 1, which has four valves. Starting with the intake valve, insert a feeler gauge of the correct thickness between the valve stem and the rocker arm. Withdraw it to feel a slight drag; if there's no drag or a heavy drag, loosen the adjuster nut and back off the adjuster screw. Carefully tighten the adjuster screw until a slight drag is felt on the feeler gauge upon withdrawal. Hold the adjuster screw with a screwdriver to prevent it from turning, then tighten the locknut and recheck the clearance to ensure it hasn't changed. Repeat this process for the other intake valve and the two exhaust valves. Next, rotate the crankshaft pulley clockwise until the number 4 on the camshaft sprocket aligns with the pointer on the timing belt cover, then check and adjust the number 4 cylinder valves. Rotate the crankshaft pulley 120 degrees clockwise until the number 2 cylinder is at TDC and check and adjust its valves. Continue rotating the crankshaft pulley clockwise, following the firing order to adjust the remaining valves. Finally, install the valve covers.