Disconnect the cable from the negative terminal of the battery, then remove the spark plugs and the valve covers. Using a socket and a breaker bar on the crankshaft pulley center bolt, rotate the engine until the cam lobes on the cylinder to be checked are pointing away from the lifters. Measure the clearance of the valves with a feeler gauge, ensuring that the gauge has the specified thickness; if the clearance is correct, a slight drag should be felt when pulling it out. Record each measurement and compare them with the desired valve clearance found in the specifications, noting any that are out of specification for later reference regarding required replacement lifters. Repeat the measurement process until all valve clearances have been assessed. If any clearance is out of specification, replace the lifter with a new one that has a different thickness head to correct the clearance, which requires removing the camshafts to access the lifters. Mark the lifters to be replaced and record their corresponding valves, using a micrometer to measure the thickness of the head of each lifter precisely at the center projection on the underside. To calculate the correct thickness for a replacement lifter that will achieve the specified valve clearance, use the formula: N equal R + (M1 - M2), where N is the thickness of the new lifter, R is the thickness of the old lifter, M1 is the measured valve clearance, and M2 is the standard valve clearance. Lifters are marked on the underside to indicate their size; for example, a marking of 3.310 indicates a thickness of 3.31 mm or 0.13 inch. Finally, mark the new lifters for their destination, lubricate them with engine assembly lube, and install them. After replacing the lifters, reinstall the camshafts and timing chains, then re-check the valve clearances.
