Intake Manifold Replacement Upper
Removal Procedure
Important: This engine uses a sequential multiport fuel injection system. Connect
the injector wiring harness connectors to their appropriate fuel injector
or exhaust emissions and engine performance may be seriously affected.
- Disconnect the battery ground (negative) cable. Refer to Refer
to
Battery Negative Cable Disconnection and Connection
in Engine Electrical.
- Disconnect the vacuum hose connection from the throttle body air
inlet duct.
- Disconnect the wiring harness connection from the intake air temperature
(IAT) sensor in the throttle body air inlet duct. Refer to
Intake Air Temperature Sensor Replacement
in Engine Controls-3.1L.
- Remove the throttle body air inlet duct.
- Drain the engine coolant from the cooling system. Refer to
Cooling System Draining and Filling
in Engine Cooling.
- Remove the accelerator control and cruise control cables with
bracket from the throttle body. Refer to
Accelerator Control Cable Bracket Replacement
in Engine Controls -
3.1L.
- Disconnect the wiring harness connectors from the throttle body.
• | Throttle position (TP) sensor |
• | Idle air control (IAC) valve |
- Disconnect the (left) front spark plug wires. Refer to
Spark Plug Wire Harness Replacement
in Engine
Electrical.
- Disconnect the wiring harness attachment clips.
• | Camshaft position (CMP) sensor wiring harness |
• | Left (front) spark plug wire harness |
- Disconnect the thermostat bypass pipe coolant hoses from the throttle
body.
- Remove the ignition coil bracket with the coils, the purge solenoid
and the vacuum canister solenoid. Refer to
Ignition Control Module Replacement
and
Evaporative Emission Canister Purge Solenoid Valve Replacement
in Engine Controls - 3.1L.
- Disconnect the vacuum
hose at the manifold air pressure (MAP) sensor and upper intake manifold.
- Remove the manifold air pressure (MAP) sensor and the bracket.
Refer to
Manifold Absolute Pressure Sensor Replacement
in Engine Controls - 3.1L.
- Disconnect the emission
control vacuum harness.
- Disconnect the vacuum hose connections from the upper intake manifold.
• | Automatic transaxle vacuum modulator hose |
• | Heater and air conditioning vacuum source hose |
• | Fuel pressure regulator |
- Remove the generator brace. Refer to
Generator Brace Replacement
in Engine Electrical.
- Remove the generator bracket. Refer to
Generator Bracket Replacement
in Engine Electrical.
- Remove the exhaust gas
recirculation (EGR) valve. Refer to
Exhaust Gas Recirculation Valve Replacement
in Engine Controls-3.1L.
- Remove the right (rear)
upper intake manifold bolts and studs.
- Remove the left (front)
upper intake manifold bolts.
- Remove the upper intake manifold.
- Remove the upper intake
manifold gasket.
- If replacing the upper
intake manifold, remove the throttle body. Refer to
Throttle Body Assembly Replacement
in Engine Controls -
3.1L.
- Clean the seal surfaces on the manifold with degreaser.
Installation Procedure
- If removed, install the
throttle body. Refer to
Throttle Body Assembly Replacement
in Engine Controls - 3.1L.
- Install the upper intake
manifold gasket.
- Install the upper intake
manifold.
- Loosely install the left (front) upper intake manifold bolts.
- Loosely install the right
(rear) upper intake manifold bolts and studs.
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 upper
intake manifold bolts and studs.
Tighten
Tighten the upper intake manifold bolts and studs to 25 N·m
(18 lb ft).
- Install the exhaust gas
recirculation (EGR) valve. Refer to
Exhaust Gas Recirculation Valve Replacement
in Engine Controls - 3.1L.
- Install the generator bracket. Refer to
Generator Bracket Replacement
in Engine Electrical.
- Install the generator brace. Refer to
Generator Brace Replacement
in Engine Electrical.
- Connect the vacuum hose connections to the upper intake manifold.
• | Automatic transaxle vacuum modulator hose |
• | Heater and air conditioning vacuum source hose |
• | Fuel pressure regulator |
- Connect the emission control
vacuum harness.
- Install the manifold air pressure (MAP) sensor and bracket. Refer
to
Manifold Absolute Pressure Sensor Replacement
in Engine Controls - 3.1L.
- Connect the vacuum hose
at the manifold air pressure (MAP) sensor and the upper intake manifold.
- Install the ignition coil bracket with the coils, the purge solenoid
and the vacuum canister solenoid. Refer to
Ignition Control Module Replacement
and
Evaporative Emission Canister Purge Solenoid Valve Replacement
in Engine Controls - 3.1L.
- Connect the thermostat bypass pipe coolant hoses to the throttle
body.
- Connect the wiring harness attachment clips.
• | Camshaft position (CMP) sensor wiring harness |
• | Left (front) spark plug wire harness |
- Connect the left (front) spark plug wires. Refer to
Spark Plug Wire Harness Replacement
in Engine
Electrical.
- Connect the wiring harness connectors to the throttle body.
• | Throttle position (TP) sensor |
• | Idle air control (IAC) valve |
- Install the accelerator control and cruise control cables with
bracket to the throttle body. Refer to
Accelerator Control Cable Bracket Replacement
in Engine Controls -
3.1L.
- Fill the cooling system with engine coolant. Refer to
Cooling System Draining and Filling
in Engine Cooling.
- Install the throttle body air inlet duct.
- Connect the wiring harness connection to the intake air temperature
(IAT) sensor in the throttle body air inlet duct. Refer to
Intake Air Temperature Sensor Replacement
in Engine Controls -
3.1L.
- Connect the vacuum hose connection to the throttle body air inlet
duct.
- Connect the battery ground (negative) cable. Refer to Refer to
Battery Negative Cable Disconnection and Connection
in Engine Electrical.
Intake Manifold Replacement Lower
Removal Procedure
Important: This engine uses a sequential multiport fuel injection system. Injector wiring
harness connectors must be connected to their appropriate fuel injector or exhaust
emissions and engine performance may be seriously affected.
- Disconnect the battery ground (negative) cable. Refer to
Battery Negative Cable Disconnection and Connection
in Engine Electrical.
- Remove the upper intake manifold. Refer to
Intake Manifold Replacement
.
- Remove the left (front) valve rocker arm cover. Refer to
Valve Rocker Arm Cover Replacement
.
- Remove the right (rear) valve rocker arm cover. Refer to
Valve Rocker Arm Cover Replacement
.
- Disconnect the engine coolant temperature
(ECT) wiring harness.
- Disconnect and remove the fuel injector
and manifold air pressure (MAP) wiring harness.
- Remove the fuel pipe clip bolt.
- Remove the fuel pipe clip.
- Disconnect the fuel feed pipe from the fuel injector rail.
- Disconnect the fuel return pipe from the fuel injector rail.
- Remove the fuel injector rail. Refer to
Fuel Injection Fuel Rail Assembly Replacement
in Engine Controls - 3.1L.
- Remove the power steering pump from the front engine cover and reposition.
Refer to
Power Steering Pump Replacement
in
Power Steering System.
- Disconnect the heater inlet pipe with heater hose from the lower intake manifold
and reposition. Refer to Heater Pipe Replacement - Inlet (3.1L)
in HVAC.
- Disconnect the radiator inlet hose from the engine. Refer to
Radiator Inlet Hose Replacement
in Engine Cooling.
- Disconnect the thermostat bypass hose from
the thermostat bypass pipe and lower intake manifold pipe.
- Remove the lower intake manifold bolts.
- Remove the lower intake manifold.
- Remove the valve rocker arms and the push rods.
- Remove
the lower intake manifold gaskets and seals.
- Clean the lower intake manifold gasket and seal surfaces on the cylinder
heads and the engine block.
- Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
- Remove all the loose RTV sealer.
- If replacing the lower intake manifold remove
the engine coolant temperature (ECT) sensor.
- If replacing the lower intake manifold remove the water outlet bolts.
- Remove the water outlet.
- If replacing the lower intake manifold remove
the thermostat.
Installation Procedure
- If removed, install the thermostat.
- If removed, install the water outlet.
Notice: Refer to Fastener Notice in the Preface section.
- Install the water outlet bolts.
Tighten
Tighten the water outlet bolts to 25 N·m (18 lb ft).
- If removed, install the engine coolant temperature
(ECT) sensor.
Tighten
Tighten the coolant temperature sensor to 23 N·m (17 lb ft).
Important: All gasket-mating surfaces need to be free of oil, and foreign material. Use
GM P/N 12346139 (Canadian P/N 10953463) or equivalent
to clean surfaces.
- Install the lower intake manifold gaskets.
- With gaskets in place apply a small drop 8-10 mm (0.31-0.39 inch)
of RTV Sealer GM P/N 12346141 (Canadian P/N 10953433)
or equivalent to the 4 corners of the intake manifold to block joint (1).
- Connect the 2 small drops with a bead of RTV Sealer that is between
8-10 mm (0.31-0.39 inch) wide and 3.0-5.0 mm
(0.10.20 inch) thick (2).
- Install the valve rocker arms and pushrods. Refer to
Valve Rocker Arm and Push Rod Replacement
.
- Install the lower intake manifold .
Notice: Refer to Fastener Notice in the Preface section.
Important: All lower intake manifold bolts need to be cleaned, free of any foreign material,
and reused only if new bolts are unavailable. Use GM P/N 12345382 (Canadian P/N 10953489)
or equivalent and apply to the old intake manifold bolt threads.
Important: Manufacturer recommends the center bolts be fully torqued before the diagonal
bolts to assure proper seal ability.
Important: Lower intake manifold bolts in location 6 and 7 should be torqued
to specification using a crows foot type tool.
- Install the lower intake manifold bolts.
Tighten
- Tighten the lower intake manifold bolts in sequence to 7 N·m
(62 lb in) on the first pass.
- Tighten the lower intake manifold bolts (1,2,3,4) in sequence to
13 N·m (115 lb in) on the final pass.
- Tighten the lower intake manifold bolts (5,6,7,8) in sequence to 25 N·m
(18 lb ft) on the final pass.
- Connect the thermostat bypass hose to the
thermostat bypass pipe and lower intake manifold pipe.
- Connect the radiator inlet hose to the engine. Refer to
Radiator Inlet Hose Replacement
in Engine Cooling.
- Install the heater inlet pipe.
- Install the heater inlet pipe nut.
Tighten
Tighten the heater inlet pipe nut to 25 N·m (18 lb ft).
- Install the power steering pump to the front engine cover. Refer to
Power Steering Pump Replacement
in Power Steering System.
Important: Do not press on the fuel pressure regulator valve when installing the fuel injector
rail assembly.
- Install the fuel injector rail assembly.
16.1. | Install the fuel injector O-rings using GM P/N 12345616
(Canadian P/N 993182) or equivalent. |
16.2. | Install the injector nozzles into the lower intake manifold injector bores. |
16.3. | Press on the injector rail using the palms of both hands until the injectors
are fully seated. |
- Install the fuel injector rail bolts.
Tighten
Tighten the fuel injector rail bolts to 10 N·m (89 lb in).
- Connect the fuel return pipe to the fuel injector rail. Refer to
Fuel Hose/Pipes Replacement - Filter to Engine
in Engine
Controls - 3.1L.
- Connect the fuel feed pipe to the fuel injector rail. Refer to
Fuel Hose/Pipes Replacement - Filter to Engine
in Engine Controls - 3.1L.
- Install the fuel feed and return pipe retaining
clip.
- Install the fuel feed and return pipe retaining clip bolt.
Tighten
Tighten the fuel feed and return pipe retaining clip bolt to 8 N·m
(71 lb in).
- Install and connect the fuel injector and
the manifold air pressure (MAP) wiring harness.
- Connect the engine coolant temperature (ECT)
electrical connector.
- Install the right (rear) valve rocker arm cover. Refer to
Valve Rocker Arm Cover Replacement
.
- Install the left (front) valve rocker arm cover. Refer to
Valve Rocker Arm Cover Replacement
.
- Install the upper intake manifold. Refer to
Intake Manifold Replacement
.
- Connect the negative battery cable. Refer to
Battery Negative Cable Disconnection and Connection
in Engine Electrical.