GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

    Important: Some models use a second design inverted tooth timing drive system on the secondary drive components. Refer to Camshaft Timing Drive Design Identification for more information on specific changes.

  1. Clean all the following components with solvent:
  2. • Crankshaft sprocket
    • Primary timing drive chain
    • Primary timing drive chain shoe
    • Primary timing drive chain guides
    • Primary timing drive chain tensioner
    • Secondary timing drive chains
    • Secondary timing drive chain shoes
    • Secondary timing drive chain guides
    • Secondary timing drive chain tensioners
    • Timing component fastening bolts
  3. Clean each camshaft position actuator's exterior with solvent.
  4. Caution: Refer to Safety Glasses Caution in the Preface section.

  5. Dry the timing components with compressed air.

Visual Inspection

Camshaft Position Actuators


    Object Number: 1849184  Size: SH
  1. Inspect the front of the exhaust camshaft position actuators for the following:
  2. • Sprocket damage (1)
    • Reluctor/sensor wheel damage (2)
    • Camshaft position actuator bolt seating/sealing inner hub flange damage (3)

    Object Number: 1849185  Size: SH
  3. Inspect the back of the exhaust camshaft position actuators for the following:
  4. • Sprocket damage (1)
    • Camshaft locating pin damage (2)
    • Camshaft seating/sealing inner hub flange damage (3)
    • Blockage to the oil passages (4)
    • Loose or missing housing bolts (5)

    Object Number: 1849186  Size: SH
  5. Inspect the front of the left intake camshaft position actuators for the following:
  6. • Sprocket damage (1)
    • Reluctor/sensor wheel damage (2)
    • Camshaft position actuator oil control valve bolt seating/sealing inner hub flange damage (3)

    Object Number: 1849187  Size: SH
  7. Inspect the back of the left intake camshaft position actuators for the following:
  8. • Sprocket damage (1)
    • Camshaft locating pin damage (2)
    • Camshaft seating/sealing inner hub flange damage (3)
    • Blockage to the oil passages (4)
    • Loose or missing housing bolts (5)

    Object Number: 1849190  Size: SH
  9. Inspect the front of the right intake camshaft position actuators for the following:
  10. • Sprocket damage (1)
    • Reluctor/sensor wheel damage (2)
    • Camshaft position actuator oil control valve bolt seating/sealing inner hub flange damage (3)

    Object Number: 1849187  Size: SH
  11. Inspect the back of the right intake camshaft position actuators for the following:
  12. • Sprocket damage (1)
    • Camshaft locating pin damage (2)
    • Camshaft seating/sealing inner hub flange damage (3)
    • Blockage to the oil passages (4)
    • Loose or missing housing bolts (5)
  13. Replace a damaged camshaft position actuator.

Camshaft Position Actuator Oil Control Valves


    Object Number: 1326149  Size: SH
  1. Inspect the camshaft position actuator oil control valves for the following:
  2. • 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 oil control valve solenoid oil seal (4)
    • Damage to the bracket (5)
    • Damage to the wiring harness connection and/or terminals (6)
  3. Replace a damaged camshaft position actuator oil control valve.

Left Intermediate Sprocket with Primary and Secondary Inverted Tooth (IT) Chain


    Object Number: 1849191  Size: SH
  1. Inspect the front of the left intermediate sprocket for the following:
  2. • Damage to the primary camshaft drive chain sprocket (1)
    • Damage to the hub bearing (2)--Ensure the hub bearing spins freely. If the hub bearing wobbles, is noisy, or feels rough when rotated, replace the intermediate sprocket.
    • Damage to the bolt flange seating/sealing surface (3)

    Object Number: 1849192  Size: SH
  3. Inspect the back of the left intermediate sprocket for the following:
  4. • Damage to the left secondary camshaft drive chain sprocket (1)
    • Damage to the bearing hub-to-engine block sealing surface (2)
  5. Replace a damaged left intermediate sprocket.

Right Intermediate Sprocket with Primary and Secondary Inverted Tooth (IT) Chain


    Object Number: 1849193  Size: SH
  1. Inspect the front of the right intermediate sprocket for the following:
  2. • Damage to the right secondary camshaft drive chain sprocket (1)
    • Damage to the hub bearing (2)--Ensure the hub bearing spins freely. If the hub bearing wobbles, is noisy, or feels rough when rotated, replace the intermediate sprocket.
    • Damage to the bolt flange seating/sealing surface (3)

    Object Number: 1849194  Size: SH
  3. Inspect the back of the right intermediate sprocket for the following:
  4. • Damage to the primary camshaft drive chain sprocket (1)
    • Damage to the bearing hub-to-engine block sealing surface (2)
  5. Replace a damaged right intermediate sprocket.

Crankshaft Sprocket with Second Version Primary Inverted Tooth (IT) Chain


    Object Number: 1849196  Size: SH
  1. Inspect the crankshaft sprocket for the following:
  2. • Sprocket damage (1)
    • Bore damage (2)
    • Keyway damage (3)
  3. Replace a damaged crankshaft sprocket.

Secondary Timing Chains with Inverted Tooth (IT) Chain


    Object Number: 1545381  Size: SH
  1. Inspect the secondary timing chain for the following:
  2. • Binding or worn links (1)
    • Loose links (2)
    • Loose pins (3)
  3. Replace a damaged secondary timing chain.

Primary Timing Chain with Inverted Tooth (IT) Chain


    Object Number: 1545381  Size: SH
  1. Inspect the primary timing chain for the following:
  2. • Binding or worn links (1)
    • Loose links (2)
    • Loose pins (3)
  3. Replace a damaged primary timing chain.

Primary Timing Chain Upper Guide


    Object Number: 1210923  Size: SH
  1. Inspect the primary timing chain upper guide for the following:
  2. • Worn guide surface (1)
    • Cracked or broken guide surface (2)
    • Cracked or damaged guide base (3)
  3. Replace a damaged primary timing chain upper guide.

Primary Timing Chain Lower Guide


    Object Number: 1579175  Size: SH
  1. Inspect the primary timing chain lower guide for the following:
  2. • Worn guide surface (1)
    • Cracked or broken guide surface (2)
    • Cracked or damaged guide base (3)
  3. Replace a damaged primary timing chain lower guide.

Left Secondary Timing Chain Guide


    Object Number: 1849198  Size: SH
  1. Inspect the left secondary timing chain guides for the following:
  2. • Worn guide surface (1)
    • Cracked or broken guide surface (2)
    • Cracked or damaged guide base (3)
  3. Replace a damaged left secondary timing chain guide.

Right Secondary Timing Chain Guide


    Object Number: 1326158  Size: SH
  1. Inspect the right secondary timing chain guides for the following:
  2. • Worn guide surface (1)
    • Cracked or broken guide surface (2)
    • Cracked or damaged guide base (3)
  3. Replace a damaged right secondary timing chain guide.

Left Secondary Timing Chain Shoe


    Object Number: 1326159  Size: SH
  1. Inspect the front of the left secondary timing chain shoe for the following:
  2. • Worn shoe surface (1)
    • Cracked or broken shoe surface (2)
    • Cracked or damaged shoe (3)

    Object Number: 1326160  Size: SH
  3. Inspect the back of the left secondary timing chain shoe for a damaged, worn, or missing left secondary timing chain tensioner contact pad (1).
  4. Replace a damaged left secondary timing chain shoe.

Right Secondary Timing Chain Shoe


    Object Number: 1326161  Size: SH
  1. Inspect the front of the right secondary timing chain shoe for the following:
  2. • Worn shoe surface (1)
    • Cracked or broken shoe surface (2)
    • Cracked or damaged shoe (3)

    Object Number: 1326162  Size: SH
  3. Inspect the back of the right secondary timing chain shoe for a damaged, worn, or missing right secondary timing chain tensioner contact pad (1).
  4. Replace a damaged right secondary timing chain shoe.

Primary Timing Chain Tensioner


    Object Number: 1210924  Size: SH
  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. Reset the plunger (3) and ensure the plunger moves freely (2) in and out of the body of the tensioner. Refer to Primary Camshaft Intermediate Drive Chain Tensioner Installation .
  3. Replace a damaged primary timing chain tensioner.

Left Secondary Timing Chain Tensioner


    Object Number: 1326164  Size: SH
  1. Inspect the left secondary timing chain tensioner for damaged plunger-to-shoe contact surface (1).
  2. Inspect the left secondary timing chain tensioner for locked or binding timing chain tensioner. Reset the plunger (3) and ensure the plunger moves freely (2) in and out of the body of the tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Installation - Left Side .
  3. Replace a damaged left secondary timing chain tensioner.

Right Secondary Timing Chain Tensioner


    Object Number: 1326165  Size: SH
  1. Inspect the right secondary timing chain tensioner for damaged plunger-to-shoe contact surface (1).
  2. Inspect the right secondary timing chain tensioner for locked or binding timing chain tensioner. Reset the plunger (3) and ensure the plunger moves freely (2) in and out of the body of the tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Installation - Right Side .
  3. Replace a damaged right secondary timing chain tensioner.