For 1990-2009 cars

1. Measure the valve spring height. Refer to Engine Mechanical Specifications. If the valve spring height does not match the specifications, replace the valve spring.
2. Measure the valve spring squareness. Refer to Engine Mechanical Specifications. If the valve spring squareness does not match the specifications, replace the valve spring.
3. Inspect the valve spring seating surface of the valve rotators for wear or gouges. Replace as required.