Camshaft Sprocket Bolt Replacement

WARNING: This page is about a different variant/trim than selected.

Special Tools

EN-955-A V-Belt and Timing Tensioner Locking Pin
EN-45059-A Angle Meter
EN-52455 Open End Wrench
EN-52457 Camshaft Locking Tool
EN-52458 VCP Locking Tool
EN-52476 Flywheel Locking Tool

Equivalent regional tools: Special Tools

Removal Procedure

NOTE:

DO NOT remove the positive crankcase ventilation vacuum hose unless replacement of the hose is necessary.

The positive crankcase ventilation vacuum hose clamps are tamper-proof connections.
The turbocharger must be removed in order to install the positive crankcase ventilation vacuum hose at the turbocharger.
The camshaft cover, turbocharger, and vacuum hose can be removed together as an assembly and set aside so long as the tamper-proof connection remains intact.
The camshaft cover or turbocharger can be removed and set aside so long as the vacuum hose connection remains intact and undamaged.

Camshaft Cover - Position aside - Camshaft Cover Replacement
Camshaft Position Actuator Solenoid Valve - Intake - Remove - Camshaft Position Actuator Solenoid Valve Replacement - Intake
Camshaft Position Actuator Solenoid Valve - Exhaust - Remove - Camshaft Position Actuator Solenoid Valve Replacement - Exhaust
Starter - Remove - Starter Replacement (LIH)
Timing Belt Lower Cover - Remove - Timing Belt Lower Cover Replacement
Courtesy of GENERAL MOTORS COMPANY

NOTE:
Ensure the EN-52476 Flywheel Locking Tool (1) is properly assembled, and the timing pin plunger (3) is retracted. When using the EN-52476 Flywheel Locking Tool as an timing device, adjust the pawl armature (4) so the pawl is not engaging the teeth once installed.

EN-52476 Flywheel Locking Tool (1) - Install
Bolt (2) - Install and tighten [2x]
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Crankshaft Balancer Bolt (1) - Install

NOTE:

The engine timing is located 118.14 degrees after top dead center.

Adjust the engine to the engine timing position. Set the crankshaft in direction of engine rotation until the pin (2) of the EN-52476 Flywheel Locking Tool snaps automatically into the hole of the automatic transmission flex plate (3) or the engine flywheel.
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If the engine timing is adjusted correctly, the valves (1, 3) of the 3rd cylinder must be closed. Also the 2 flats (2) must stand in vertical position.
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NOTE:
The EN-52457 Camshaft Locking Tool has an identification for which side it must be used. Place the EN-52457 Camshaft Locking Tool with the identification mark I (1) facing upwards. Also the surface has an identification for the intake (2).

EN-52457-2 Locking Tool - Intake (5) - Install
Bolt (3, 4) - Install and tighten
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NOTE:
The EN-52457 Camshaft Locking Tool has an identification for which side it must be used. Place the EN-52457 Camshaft Locking Tool with the identification mark I (1) facing upwards. Also the surface has an identification for the exhaust (2).

EN-52457-2 Locking Tool - Exhaust (5) - Install
Bolt (3, 4) - Install and tighten [2x]
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Bolt @ EN-52458 VCP Locking Tool (2) - Loosen
EN-52458 VCP Locking Tool (1) - Adjust
EN-52458 VCP Locking Tool (1) - Install

CAUTION:

Fastener Caution

Bolt (3) - Install and tighten [4x] 6 N.m (53 lb in)
Bolt (2) - Tighten
Courtesy of GENERAL MOTORS COMPANY

Loosen the timing belt tensioner bolt (2) and release the tension from the timing belt tensioner (1). Rotate the timing belt tensioner counter-clockwise.
EN-955-10-A locking pin (3) - Install
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Install the EN-52458-3 locking tool (2) to the holes in the camshaft sprocket.
Check that the EN-52458-3 locking tool (2) sits correctly in the hole of the camshaft sprocket.
Bolt (3, 4) - Tighten [2x] 20 N.m (15 lb ft)
Camshaft Sprocket Actuator Valve Bolt (1) - Loosen [2x]
Bolt (3, 4) - Loosen [2x]
Courtesy of GENERAL MOTORS COMPANY

Bolt (3) - Remove [4x]
EN-52458 locking tool (1) - Remove
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Camshaft Sprocket Actuator Valve Bolt (1) - Remove and DISCARD [2x]

Inspection Procedure

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NOTE:
Do not use the camshaft sprocket actuator valve bolt again. Install a NEW valve during assembly. The inspection procedure below is provided for off-vehicle diagnostic purposes only.

Inspect the valve bolt for the following conditions:
- Dirt, debris, or restrictions within the oil passages (1)
- Damaged threads (2)
  If the threads of the valve are damaged, also inspect the threads in the front of the camshaft for damage.
- Dirt, debris, or restrictions within the oil inlet (3)
  If debris is detected, the engine assembly should be inspected to determine the source of contamination.
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Inspect for a sticking valve spool or broken valve spool spring.
Depress the valve spool into the housing. The valve should move freely with no binding or sticking and minimal resistance inward. When released, the valve spring should return the spool to the proper extended position (1) of 11.9 - 13.1 mm (0.469 - 0.516 in).

Installation Procedure

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Camshaft Sprocket Actuator Valve Bolt (1) - Install NEW and hand tighten [2x]
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Timing Belt Tensioner (1) - Install
Timing Belt Tensioner Bolt (2) - Loosely install
Timing Belt Idler Pulley (4) - Install

CAUTION:

Fastener Caution

Timing Belt Idler Pulley Bolt (3) - Install and tighten 36 N.m (27 lb ft)
Courtesy of GENERAL MOTORS COMPANY

EN-955-10-A pin (2) - Remove

NOTE:

The nominal position of the timing belt tensioner is when the mobile index (5) is between the gap in the front plate (4).

Tension the timing belt tensioner (1) to the nominal position and an additional a = 10 degrees. Rotate the timing belt tensioner clockwise.
Timing Belt Tensioner Bolt (3) - Tighten 36 N.m (27 lb ft)
Courtesy of GENERAL MOTORS COMPANY

Bolt (2) - Loosen
Slide the EN-52458 VCP Locking Tool (1) apart.
EN-52458 VCP Locking Tool (1) - Install
Bolt (3) - Install and tighten [4x] 6 N.m (53 lb in)
Bolt (2) - Tighten
Courtesy of GENERAL MOTORS COMPANY

Install the EN-52458-3 locking tool (2) to the holes in the intake camshaft sprocket.
Check that the EN-52458-3 locking tool (2) sits correctly in the hole of the camshaft sprocket.

NOTE:

A second technician is required.

Tighten the EN-52458-3 locking tool (2) to 20 N.m (15 lb ft). Rotate the EN-52458-3 locking tool clockwise.
While holding the EN-52458-3 locking tool to 20 N.m (15 lb ft), tighten the bolt (3) to 20 N.m (15 lb ft).

CAUTION:

Torque-to-Yield Fastener Warning

Camshaft Sprocket Actuator Valve Bolt (1) @ Intake Camshaft - Tighten
1. First Pass: 50 N.m (37 lb ft)
2. Final Pass: 28 degrees, use the EN-45059 meter
Courtesy of GENERAL MOTORS COMPANY

Install the EN-52458-3 locking tool (3) to the holes in the exhaust camshaft sprocket.
Check that the EN-52458-3 locking tool (3) sits correctly in the hole of the camshaft sprocket.

NOTE:

A second technician is required.

Tighten the EN-52458-3 locking tool (3) to 20 N.m (15 lb ft). Rotate the EN-52458-3 locking tool clockwise.
While holding the EN-52458-3 locking tool to 20 N.m (15 lb ft), tighten the bolt (2) to 20 N.m (15 lb ft).

CAUTION:

Torque-to-Yield Fastener Warning

Camshaft Sprocket Actuator Valve Bolt (1) @ Exhaust Camshaft - Tighten
1. First Pass: 50 N.m (37 lb ft)
2. Final Pass: 28 degrees, use the EN-45059 meter
Courtesy of GENERAL MOTORS COMPANY

Bolt (3) - Remove [4x]
EN-52458 locking tool (1) - Remove
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Bolt (3, 4) - Remove [2x]
EN-52457-1 locking tool (5) - Remove
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Bolt (3, 4) - Remove
EN-52457-2 locking tool (5) - Remove
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Turn the crankshaft 720 degrees in the direction of engine rotation by the crankshaft balancer bolt (1) until the pin (2) of the EN-52476 lock tool snaps automatically into the hole (3) of the automatic transmission flex plate or the engine flywheel.
Courtesy of GENERAL MOTORS COMPANY

NOTE:
The nominal position of the timing belt tensioner is when the mobile index (2) sits in the middle between the gap of the front plate (3). A tolerance is given when half of the hole (4) is visible (+/- 5 degrees).

Check that the timing belt tensioner (1) is in the nominal position.
If not, repeat the step to adjust the tensioner.
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NOTE:
The EN-52457 Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457 Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification intake (2) for use on the intake camshaft.

EN-52457-2 locking tool (5) @ Intake Camshaft - Install
Courtesy of GENERAL MOTORS COMPANY

NOTE:
The EN-52457 Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457 Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification exhaust (2) for use on the exhaust camshaft.

EN-52457-2 locking tool (5) - Install
If the EN-52457 Camshaft Locking Tool can be installed, the engine timing is properly adjusted.
If the EN-52457 Camshaft Locking Tool can not be installed, repeat the steps to set the engine timing.
EN-52457 Camshaft Locking Tool - Remove
Courtesy of GENERAL MOTORS COMPANY

Crankshaft Balancer Bolt (1) - Remove
Courtesy of GENERAL MOTORS COMPANY

Bolt (2) - Remove [2x]
EN-52476 Flywheel Locking Tool (1) - Remove
Timing Chain Lower Cover - Install - Timing Belt Lower Cover Replacement
Starter - Install - Starter Replacement (LIH)
Camshaft Position Actuator Solenoid Valve - Exhaust - Install - Camshaft Position Actuator Solenoid Valve Replacement - Exhaust
Camshaft Position Actuator Solenoid Valve - Intake - Install - Camshaft Position Actuator Solenoid Valve Replacement - Intake
Camshaft Cover - Install - Camshaft Cover Replacement