Valve Train Analysis

Engine

Valve Train Analysis

The following inspections are used to diagnose valve train concerns:

Valve Train Analysis - Valve Cover Removed

Check for damaged or severely worn parts rocker arm assemblies and push rods.

Valve Train Analysis - Valve Springs

- Check for broken or damaged parts.

Valve Train Analysis - Valve Spring Retainer and Valve Spring Retainer Keys

- Check for correct seating of the valve spring retainer key on the valve stem and in valve spring retainer.
- Check for correct seating on the valve stem.

Valve Train Analysis - Valves and Cylinder Head

- Check for plugged oil drain back holes.
- Check for worn or damaged valve tips.
- Check for missing or damaged guide-mounted valve stem seal.
- Check for damaged hydraulic lash adjuster.
- Check installed valve spring height.
- Check for missing or worn valve spring seats.

Valve Train Analysis - Camshaft Lobe Lift

Check the lift of each camshaft lobe in consecutive order and make a note of the readings.

1. Preform visual inspection.

2. Remove the glow plugs. Refer to Glow Plug System - 6.7L Diesel Glow Plug.

3. Remove the rocker arm assemblies for the affected cylinders. Refer to Rocker Arm Removal and Replacement.

4. Install the Dial Indicator Gauge with Holding Fixture so the needle tip of indicator is on top of the push rod.

5. Rotate the crankshaft using a breaker bar and socket attached to the crankshaft pulley retaining bolt. Rotate the crankshaft until the base circle of the camshaft lobe is reached.

6. Zero the Dial Indicator Gauge. Continue to rotate the crankshaft until the high lift point of the rocker arm is in the fully raised position (highest indicator reading).

7. To check the accuracy of the original indicator reading, continue to rotate crankshaft until the base circle is reached. The indicator reading should be zero. If zero reading is not obtained, repeat the measurement.

8. If the lift on any lobe is below specified service limits, install a new camshaft and valve tappets. Refer to Engine Engine - Disassembly.

9. Install the rocker arm assemblies. Refer to Rocker Arm Removal and Replacement.

10. Install the glow plugs. Refer to Glow Plug System - 6.7L Diesel Glow Plug.