Visual Inspection

Camshaft Position Actuators

Fig 1: Inspecting Front Of Exhaust Camshaft Position Actuator
Courtesy of GENERAL MOTORS CORP.
1. Inspect the front of the exhaust camshaft position actuators for the following:
   • Sprocket damage (1)
   • Loose or missing lock pin cover (2)
   • Reluctor/sensor wheel damage (3)
   • Camshaft position actuator oil control valve seating/sealing inner hub flange damage (4)
   • Blockage to the oil passages (5)
Fig 2: Locating Camshaft Alignment Pin Hole On Back Of Actuator
Courtesy of GENERAL MOTORS CORP.
2. Inspect the back of the exhaust camshaft position actuators for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole (2)
   • Camshaft seating/sealing inner hub flange damage (3)
   • Blockage to the oil passages (4)
   • Loose or missing housing bolts (5)
Fig 3: Inspecting Front Of Intake Camshaft Position Actuator
Courtesy of GENERAL MOTORS CORP.
3. Inspect the front of the intake camshaft position actuators for the following:
   • Sprocket damage (1)
   • Loose or missing lock pin cover (2)
   • Reluctor/sensor wheel damage (3)
   • Camshaft position actuator oil control valve seating/sealing inner hub flange damage (4)
   • Blockage to the oil passages (5)
Fig 4: Locating Camshaft Alignment Pin Hole
Courtesy of GENERAL MOTORS CORP.
4. Inspect the back of the intake camshaft position actuators for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole (2)
   • Camshaft seating/sealing inner hub flange damage (3)
   • Blockage to the oil passages (4)
   • Loose or missing housing bolts (5)
5. Replace a damaged camshaft position actuator.

Camshaft Position Actuator Oil Control Valve

Fig 5: Inspecting Camshaft Position Actuator Oil Control Valves
Courtesy of GENERAL MOTORS CORP.
1. Inspect the camshaft position actuator oil control valves for the following:
   • Thread damage (1)
   • Blockage to the oil passages (2)
   • Camshaft position actuator oil control valve seating/sealing flange damage (3)
   • Hex damage (4)
   • Spool valve head damage (5)
2. Replace a damaged camshaft position actuator oil control valve.

Intermediate Sprocket

Fig 6: Inspecting Front Of Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
1. Inspect the front of the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bearing bore damage (2)
   • Thrust surface damage (3)
Fig 7: Inspecting Back Of Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
2. Inspect the back of the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bearing bore damage (2)
   • Thrust surface damage (3)
3. Replace a damaged intermediate sprocket.

Crankshaft Sprocket

Fig 8: Inspecting Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
1. Inspect the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bore damage (2)
   • Keyway damage (3)
2. Replace a damaged crankshaft sprocket.

Primary and Secondary Timing Chains

Fig 9: Inspecting Primary And Secondary Timing Chains With Roller Chain
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary and/or secondary timing chain for the following:
   • Binding or worn rollers (1)
   • Loose links (2)
   • Loose pins (3)
2. Replace a damaged primary and/or secondary timing chains.

Primary Timing Chain Guide

Fig 10: Inspecting Primary Timing Chain Guide
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary timing chain guide for the following:
   • Worn guide surface (1)
   • Cracked or broken guide surface (2)
   • Cracked or damaged guide base (3)
2. Replace a damaged primary timing chain guide.

Secondary Timing Chain Guides

Fig 11: Inspecting Secondary Timing Chain Guide
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain guides for the following:
   • Worn guide surface (1)
   • Cracked or broken guide surface (2)
   • Cracked or damaged guide base (3)
2. Replace a damaged secondary timing chain guide.

Secondary Timing Chain Shoes

Fig 12: Inspecting Secondary Timing Chain Shoes
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain shoes for the following:
   • Worn shoe surface (1)
   • Cracked or broken shoe surface (2)
   • Cracked or damaged shoe (3)
2. Replace a damaged secondary timing chain shoe.

Primary Timing Chain Tensioner

Fig 13: Inspecting Primary Timing Chain Tensioner
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary timing chain tensioner for worn primary timing chain tensioner shoe surface (1).
2. Inspect the primary timing chain tensioner for locked or binding timing chain tensioner. Release the locking lever (2) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
3. Replace a damaged primary timing chain tensioner.

Secondary Timing Chain Tensioners

Fig 14: Inspecting Secondary Timing Chain Tensioner
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain tensioner for damaged plunger-to-shoe contact surface (1).
2. Inspect the secondary timing chain tensioner for locked or binding timing chain tensioner. Release the locking lever (2) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
3. Replace a damaged primary and/or secondary timing chain tensioner.

Timing Component Fasteners

1. Inspect the timing component fasteners.
2. Replace any damaged timing component fasteners, do not repair.