Visual Inspection

Camshaft Position Actuator

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the front of the right exhaust camshaft position actuators for the following:

   • Sprocket damage (1)
   • Loose or missing housing bolts (2)
   • Camshaft position actuator bolt seating/sealing inner hub flange damage (3)

2. Courtesy of GENERAL MOTORS COMPANY

   Inspect the back of the right exhaust camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft locating pin damage (2)
   • Camshaft seating/sealing inner hub flange damage (3)
   • Blockage to the oil passages (4)

3. Courtesy of GENERAL MOTORS COMPANY

   Inspect the front of the right intake camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft position actuator oil control valve bolt seating/sealing inner hub flange damage (2)

4. Courtesy of GENERAL MOTORS COMPANY

   Inspect the back of the right intake camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft locating pin damage (2)
   • Blockage to the oil passages (3)
   • Loose or missing housing bolts (4)

5. Courtesy of GENERAL MOTORS COMPANY

   Inspect the front of the left exhaust camshaft position actuators for the following:

   • Sprocket damage (1)
   • Loose or missing housing bolts (2)
   • Camshaft position actuator bolt seating/sealing inner hub flange damage (3)

6. Courtesy of GENERAL MOTORS COMPANY

   Inspect the back of the left exhaust camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft locating pin damage (2)
   • Camshaft seating/sealing inner hub flange damage (3)
   • Blockage to the oil passages (4)

7. Courtesy of GENERAL MOTORS COMPANY

   Inspect the front of the left intake camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft position actuator oil control valve bolt seating/sealing inner hub flange damage (2)

8. Courtesy of GENERAL MOTORS COMPANY

   Inspect the back of the left intake camshaft position actuators for the following:

   • Sprocket damage (1)
   • Camshaft locating pin damage (2)
   • Blockage to the oil passages (3)
   • Loose or missing housing bolts (4)
9. Replace a damaged camshaft position actuator.

Camshaft Position Actuator Solenoid Valve

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the camshaft position actuator solenoid valves for the following:

   • Blockage to the oil passage (1)
   • Missing or damaged oil screen clip (2)
   • Blockage or damage to the oil screen (3)
   • Damage to the sealing surface for the camshaft position actuator solenoid valve solenoid oil seal (4)
   • Damage to the wiring harness connection and/or terminals (5)
   • Damage to the bracket (6)

2. Courtesy of GENERAL MOTORS COMPANY

   Inspect the camshaft position actuator solenoid valves for the following:

   • Blockage to the oil passage (1)
   • Missing or damaged oil screen clip (2)
   • Blockage or damage to the oil screen (3)
   • Damage to the bracket (4)
   • Damage to the wiring harness connection and/or terminals (5)
3. Replace a damaged camshaft position actuator solenoid valve.

Camshaft Position Sensor

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the camshaft position sensor for the following:

   • Damage to the camshaft position sensor (1)
   • Damage to the sealing surface for the camshaft position sensor (2)
   • Damage to the wiring harness connection and/or terminals (3)
   • Damage to the bracket (4)
2. Replace a damaged camshaft position sensor.

Crankshaft Sprocket

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the crankshaft sprocket for the following:

   • Sprocket damage (1)
   • Bore damage (2)
   • Keyway damage (3)
2. Replace a damaged crankshaft sprocket.

Crankshaft Sprocket

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the crankshaft sprocket for the following:

   • Sprocket damage (1)
   • Bore damage (2)
   • Keyway damage (3)
2. Replace a damaged crankshaft sprocket.

Oil Pump Sprocket

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the crankshaft sprocket for the following:

   • Sprocket damage (1)
   • Bore damage (2)
   • Bore damage (3)
   • Keyway damage (4)
2. Replace a damaged crankshaft sprocket.

Timing Chains with Inverted Tooth (IT) Chain

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the timing chain for the following:

   • Binding or worn links (1)
   • Loose links (2)
   • Loose pins (3)
2. Replace a damaged timing chain.

Timing Chain Guide

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the 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 upper guide.

Timing Chain Guide

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the 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 upper guide.

Timing Chain Tensioner

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the timing chain tensioner for worn timing chain tensioner surface (1).

2. Inspect the timing chain tensioner for worn timing chain tensioner spring (2).
3. Inspect the timing chain tensioner for locked or binding timing chain tensioner. Reset the plunger (4) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
4. Replace a damaged primary timing chain tensioner.

Timing Chain Guide

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the 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 upper guide.

Timing Chain Guide

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the 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 upper guide.

Timing Chain Tensioner

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the timing chain tensioner for worn timing chain tensioner surface (1).

2. Inspect the timing chain tensioner for worn timing chain tensioner spring (2).
3. Inspect the timing chain tensioner for locked or binding timing chain tensioner. Reset the plunger (4) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
4. Replace a damaged primary timing chain tensioner.

Timing Chain Tensioner

1. Courtesy of GENERAL MOTORS COMPANY

   Inspect the timing chain tensioner for worn timing chain tensioner surface (1).

2. Cracked or broken tensioner surface (2)
3. Inspect the timing chain tensioner for worn timing chain tensioner spring (3).
4. Replace a damaged primary timing chain tensioner.