Is a light tapping sound heard from the engine?

Go to Step 2

System OK

Inspect the valve springs.

Are the springs weak or broken?

Go to Cylinder Head Disassemble

Go to Step 3

Inspect the valves.

Are the valves sticking or warped?

Go to Cylinder Head Disassemble

Go to Step 4

Inspect the valve lifters.

Are the valve lifters dirty, stuck, or worn?

Go to Cylinder Head Disassemble

Go to Step 5

Inspect the camshaft lobes.

Are the camshaft lobes damaged or improperly machined?

Go to Cylinder Head Disassemble

Go to Step 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

Inspect the valve guides.

Are the valve guides worn?

Go to Cylinder Head Disassemble

Go to Step 8

Inspect the valve spring seat.

Is the valve spring seat incorrect?

Go to Cylinder Head Disassemble

System OK