Camshaft Timing Chain Adjustment

Special Tools

• EN-952  Fixing Pin
• EN-953-A  Fixing Tool
• EN-45059  Angle Meter
• EN-49977-100  Fixation Sensor Discs

For equivalent regional tools, refer to Special Tools .

1. Remove the ignition coil. Refer to Ignition Coil Replacement .
2. Remove the camshaft cover. Refer to Camshaft Cover Replacement .
3. Remove the camshaft position actuator solenoid valves. Refer to Camshaft Position Actuator Solenoid Valve Replacement .
4. Remove the right front wheelhouse liner. Refer to Front Wheelhouse Liner Replacement .
5. Remove the front compartment insulator. Refer to Front Compartment Insulator Replacement .
6. Set the crankshaft balancer in the direction of the engine rotation to "1st cylinder TDC", for this rotate the engine clockwise until the bore (2) in the crankshaft balancer aligns with the mark (1) on the engine front cover.
   Fig 1: Bore And Mark

   Courtesy of GENERAL MOTORS COMPANY
7. Remove the crankshaft bearing cap tie plate hole plug (2) and the seal ring (1).
   Fig 2: Crankshaft Bearing Cap Tie Plate Hole Plug And Seal Ring

   Courtesy of GENERAL MOTORS COMPANY
8. Install the EN-952  fixing pin (1) to hold the crankshaft in "1st cylinder TDC" position.
   Fig 3: Fixing Pin

   Courtesy of GENERAL MOTORS COMPANY
   CAUTION: To ensure proper crankshaft top dead center (TDC) alignment, the retention pin should fit easily through the bore in the crankshaft tie plate and into the crankshaft. Binding of the retention pin could affect proper engine timing.
9. Loosen the intake camshaft sprocket bolt (2) while holding the hexagon of the intake camshaft with a wrench (1) until the camshaft position exciter wheel is clearly rotatable.
   Fig 4: Intake Camshaft Sprocket Bolt And Wrench

   Courtesy of GENERAL MOTORS COMPANY
10. Loosen the exhaust camshaft sprocket bolt while holding the hexagon of the exhaust camshaft with a wrench until the camshaft position exciter wheel is clearly rotatable.
11. Adjust the camshafts so that the EN-953-A  fixing tool (1) can be installed.
    Fig 5: Fixing Tool

    Courtesy of GENERAL MOTORS COMPANY
    NOTE: The fixing tool should be installed completely to both camshaft grooves without high effort.
12. Remove the 2 upper timing chain guide bolts (1).
    Fig 6: Upper Timing Chain Guide And Bolts

    Courtesy of GENERAL MOTORS COMPANY
13. Remove the upper timing chain guide (2).
14. Install the EN-49977-200  fixing tool (2) and adjust the gearing of the fixing tool so it engages with the intake camshaft sprocket gearing (1).
    Fig 7: Intake Camshaft Sprocket Gearing And Special Tool

    Courtesy of GENERAL MOTORS COMPANY
    NOTE: Push the fixing tool in the direction of the arrow to ensure it engages without clearance.
15. Tighten the 2 fastening bolts (1) of the EN-49977-200  fixing tool while pushing the fixing tool in direction of the arrow.
    Fig 8: Adjuster Bolt And Fastening Bolts

    Courtesy of GENERAL MOTORS COMPANY
16. Tighten the adjuster bolt (2).
17. Install the EN-49977-100  fixation (2) to find and hold the camshaft position exciter wheels in the correct position.
    Fig 9: Fastening Bolts And Fixation Tool

    Courtesy of GENERAL MOTORS COMPANY
    NOTE: A wrong installation position is possible. Make sure that the fixation tool is installed without clearance to the cylinder head in areas (3) and (5).
18. Tighten the 2 fastening bolts (6) of the EN-49977-100  fixation.
19. Tighten the intake camshaft sprocket bolt (4) while holding the hexagon (1) of the intake camshaft a first pass to 50 N.m (37 lb ft).
    CAUTION: Refer to Fastener Caution .
    CAUTION: Refer to Torque-to-Yield Fastener Caution .
20. Tighten the intake camshaft sprocket bolt (4) while holding the hexagon (1) of the intake camshaft a final pass to an additional 60 degrees, using the EN-45059  meter.
21. Tighten the exhaust camshaft sprocket bolt while holding the hexagon of the exhaust camshaft a first pass to 50 N.m (37 lb ft).
    CAUTION: Refer to Torque-to-Yield Fastener Caution .
22. Tighten the exhaust camshaft sprocket bolt while holding the hexagon of the exhaust camshaft a final pass to an additional 60 degrees, using the EN-45059  meter.
23. Remove the EN-49977-100  fixation and the EN-49977-200  fixing tool.
24. Install the upper timing chain guide (2).
    Fig 10: Upper Timing Chain Guide And Bolts

    Courtesy of GENERAL MOTORS COMPANY
25. Install the 2 upper timing chain guide bolts (1) and tighten to 8 N.m (71 lb in).
26. Remove the EN-953-A  fixing tool.
27. Remove the EN-952  fixing pin.
28. Rotate the crankshaft for 720° and check the engine timing again. Repeat the adjustment procedure if necessary.
29. Install the crankshaft bearing cap tie plate hole plug and seal ring and tighten to 40 N.m (30 lb ft).
30. Install the front compartment insulator. Refer to Front Compartment Insulator Replacement
31. Install the right front wheelhouse liner. Refer to Front Wheelhouse Liner Replacement
32. Install the camshaft position actuator solenoid valves. Refer to Camshaft Position Actuator Solenoid Valve Replacement .
33. Install the camshaft cover. Refer to Camshaft Cover Replacement .
34. Install the ignition coil. Refer to Ignition Coil Replacement .