For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Is a light tapping sound heard from the engine? | Go to Step 2 | System OK
2 | Inspect the valve springs. Are the springs weak or broken? | Go to Cylinder Head Disassemble | Go to Step 3
3 | Inspect the valves. Are the valves sticking or warped? | Go to Cylinder Head Disassemble | Go to Step 4
4 | Inspect the valve lifters. Are the valve lifters dirty, stuck, or worn? | Go to Cylinder Head Disassemble | Go to Step 5
5 | Inspect the camshaft lobes. Are the camshaft lobes damaged or improperly machined? | Go to Camshaft Replacement | Go to Step 6
6 | Inspect the oil supply to the valve train. Is the oil supply insufficient or poor? | Go to Cylinder Head Disassemble | Go to Step 7
7 | Inspect the valve guides. Are the valve guides worn? | Go to Cylinder Head Disassemble | Go to Step 8
8 | Inspect the valve spring seat. Is the valve spring seat incorrect? | Go to Cylinder Head Disassemble | System OK