Removal Procedure
Important: The intake manifold, throttle body, fuel rail, and injectors may be
removed as an assembly. If not servicing the individual components, remove
the manifold as a complete assembly.
- Remove the throttle body. Refer to
Throttle Body Assembly Replacement
in Engine Controls - 4.8L, 5.3L,
and 6.0L.
- Remove the fuel injectors. Refer to
Fuel Injector Replacement
in Engine Controls - 4.8L, 5.3L,
and 6.0L.
- Disconnect the following
electrical connectors:
• | Manifold absolute pressure (MAP) sensor (1) |
• | Exhaust gas recirculation (EGR) valve, if equipped. |
- Remove the knock sensor harness electrical connector from the
intake manifold.
- Set the electrical harness aside.
- If equipped, remove the
following EGR pipe bolts:
- If equipped, remove the EGR pipe with valve.
- If equipped, remove the EGR pipe gasket from the exhaust manifold.
- If equipped with vacuum
assisted brakes, remove the vacuum brake booster hose from the rear of the
intake manifold.
- Remove the positive crankcase
ventilation (PCV) hose with valve.
- Remove the MAP sensor
(1) from the intake manifold.
- Remove the accelerator control cable bracket bolts (1).
- Remove the accelerator control cable bracket (2) from the intake
manifold.
- Remove the evaporative
emission (EVAP) purge solenoid vent tube by performing the following:
14.1. | Remove the EVAP tube end (2) from the solenoid (1). |
14.2. | Squeeze the EVAP pipe quick connect fitting (3) retainer together. |
14.3. | Remove the EVAP tube end (3) from the vapor pipe. |
- Remove the EVAP purge
solenoid bolt (2), solenoid (3), and isolator (1) from the intake manifold.
- Remove the intake manifold
bolts.
- Remove the intake manifold.
- Remove the intake manifold gaskets (1) from the intake manifold.
- Discard the old intake manifold gaskets.
- Clean and inspect the intake manifold. Refer to
Intake Manifold Cleaning and Inspection
in the Engine Mechanical
- 4.8L, 5.3L, and 6.0L Unit Repair.
- If equipped with EGR, clean the gasket surfaces of the EGR pipe
and the exhaust manifold.
Installation Procedure
- Install new intake manifold gaskets (1) to the intake manifold.
- Install the intake manifold.
- Apply a 5 mm (0.20 in) band of threadlock GM U.S. P/N 12345382,
Canada P/N 10953489, or equivalent to the threads of the intake
manifold bolts.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the intake
manifold bolts.
Tighten
- Tighten the intake manifold bolts a first pass in sequence to
5 N·m (44 lb in).
- Tighten the intake manifold bolts a final pass in sequence to
10 N·m (89 lb in).
- Install the EVAP purge
solenoid (3), isolator (1), and bolt (2) to the intake manifold.
Tighten
Tighten the EVAP purge solenoid bolt to 10 N·m (89 lb in).
- Install the EVAP purge
solenoid vent tube to the solenoid (1) and vapor pipe.
- Install the accelerator control cable bracket (2) to the intake manifold.
- Install the accelerator control cable bracket bolts (1).
Tighten
Tighten the accelerator control cable bracket bolts to 10 N·m
(89 lb in).
Important: Lightly coat the MAP sensor seal with clean engine oil before installing.
- Install the MAP sensor (1) to the intake manifold.
- Install the PCV hose with
valve.
- If equipped with vacuum
assisted brakes, install the vacuum brake booster hose to the
rear of the intake manifold.
- If equipped, position
a new EGR pipe gasket on the exhaust manifold.
- If equipped, install the EGR pipe with valve.
- If equipped, install the following EGR pipe bolts until snug:
- If equipped, tighten the EGR pipe bolts.
Tighten
• | Tighten the EGR valve pipe-to-intake manifold bolts to 10 N·m
(89 lb in). |
• | Tighten the EGR valve pipe-to-cylinder head bolts to 50 N·m
(37 lb ft). |
• | Tighten the EGR valve pipe-to-exhaust manifold bolts to 30 N·m
(22 lb ft). |
- Route the electrical harness into position over the engine.
- Connect the knock sensor
harness electrical connector to the intake manifold.
- Connect the following electrical connectors.
- Install the fuel injectors. Refer to
Fuel Injector Replacement
in Engine Controls - 4.8L, 5.3L,
and 6.0L.
- Install the throttle body. Refer to
Throttle Body Assembly Replacement
in Engine Controls -
4.8L, 5.3L, and 6.0L.