Diagnosing Valve Train Noise

To diagnose and correct noisy hydraulic lifters and valve train components, use the following procedures:

1. With engine and oil at normal operating temperature, check oil pressure at 3000 rpm. If oil pressure is above 50 psi or below 5 psi, inspect oil pump, crankcase passages and oil hoses for restrictions or blockage. Repair or replace parts as necessary.

2. With engine running, raise push rod cover at the noisy lifter and check to see that oil is reaching the tappet. If oil is not reaching the tappet, inspect the passages in the tappet, tappet block and right crankcase for restrictions or blockage.

If oil is reaching the tappet, remove the hydraulic unit and inspect per procedure listed under "Valve Tappets and Guides." Clean tappet bore of all foreign material.

Replace hydraulic unit if necessary.

3. Examine push rod, hydraulic unit, tappet and tappel block for proper fits and any signs of unusual wear. Replace parts as necessary.

4. Visually inspect camshaft lobes for abnormal wear.

5. Remove camshaft and pinion gear, clean and inspect for wear and fit. Measure pitch diameters and check for out of round condition. Replace parts as necessary.

6. Remove cylinder head and rocker box assemblies. Check rocker arm end play and check for binding. Inspect valve stems for scuffing and check stem to guide clearance. Check valve seats for signs of looseness or shifting.

7. Grind valves and valve seats.

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