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.
- Remove the upper intake manifold. Refer to
Upper Intake Manifold Replacement.
- Remove the valve rocker arm covers. Refer to
Valve Rocker Arm Cover Replacement - Left Side and
Valve Rocker Arm Cover Replacement - Right Side.
- Remove the coolant crossover pipe. Refer to
Engine Coolant Crossover Pipe Replacement.
- Disconnect the fuel injector wiring harness electrical connector from the engine coolant temperature (ECT) sensor.
- Disconnect the engine wiring harness electrical connector (2) from the fuel injector inline electrical
connector.
- Disconnect the fuel injector wiring harness electrical connector from the camshaft position (CMP) sensor.
- Remove the fuel injector wiring harness connector bracket bolt from the intake
manifold.
- Remove the fuel rail bolts and rail (1).
- Remove the lower intake manifold bolts.
- Remove the lower intake manifold.
- Loosen the rocker arm bolts.
Important: Place the valve train components in a rack in order to ensure that the components are installed in the same location from which they were removed.
- Remove the rocker arms.
- Remove the push rods.
• | The intake push rods measure 147.51 mm (5.81 in). |
• | The exhaust push rods measure 154.87 mm (6.1 in). |
- 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 room temperature vulcanizing (RTV) sealer.
Installation Procedure
Important: All gasket-mating surfaces need to be free of oil and foreign material. Use cleaner to clean the surfaces. Refer to
Adhesives, Fluids, Lubricants, and Sealers.
Important: RTV sealer is NOT to be placed under the lower intake manifold gaskets.
- Install the lower intake manifold gaskets and seals.
- Coat the ends of the push rods using prelube GM P/N 12345501 (Canadian P/N 992704)
or equivalent.
- Install push rods in their original location.
• | The intake pushrods are identified with yellow stripes. |
• | The exhaust pushrods are identified with green stripes. |
- Coat the rocker arm friction surfaces using prelube GM P/N 12345501 (Canadian P/N 992704) or equivalent.
Important: Shims (P/N 88894006) may be required under the valve rocker arm pedestals if reconditioning has been performed on the cylinder head or its components.
- Install the rocker arms in their original locations.
Notice: Refer to Fastener Notice in the Preface section.
- Install the rocker arm bolts.
Tighten
Tighten the bolts to 34 N·m (25 lb ft).
- With the NEW gaskets and seals in place, apply a small drop, 8-10 mm (0.31-0.39 in)
of RTV sealer to the 4 corners of the intake manifold to block joints (1). Refer to
Adhesives, Fluids, Lubricants, and Sealers.
- Install the lower intake manifold.
Notice: Maximum gasket performance is achieved when using new fasteners, which
contain a thread-locking patch. If the fasteners are not replaced,
a thread locking chemical must be applied to the fastener threads. Failure
to replace the fasteners or apply a thread-locking chemical MAY reduce
gasket sealing capability.
Notice: Failure to tighten vertical bolts before the diagonal bolts may cause
an oil leak.
- Apply sealer to the lower intake manifold bolt threads. Refer to
Adhesives, Fluids, Lubricants, and Sealers.
- Install the lower intake manifold bolts.
- Tighten the lower intake manifold bolts in the sequence shown.
Tighten
- Tighten the center lower intake manifold bolts (1, 2, 3, 4) in sequence to 20 N·m (15 lb ft).
- Tighten the visible corner lower intake manifold bolts (5, 8) to 25 N·m (18 lb ft).
- Tighten the hidden corner lower intake manifold bolts (6, 7) to 25 N·m (18 lb ft).
- Inspect the fuel rail, fuel injectors for damage and replace as necessary.
- Lubricate and install NEW injector lower O-rings seals onto the injectors. Lubricate the NEW O-rings seals with GM P/N 12345616 (Canadian P/N 993182).
- Install the injector nozzles into the lower intake manifold injector bores.
- 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 bolts to 10 N·m (89 lb in).
- Position the fuel injector wiring harness electrical connector bracket to the
intake manifold and install the bolt.
Tighten
Tighten the bolt to 14 N·m (10 lb ft).
- Connect the fuel injector wiring harness electrical connector to the CMP sensor.
- Connect the engine wiring harness electrical connector (2) to the fuel injector inline electrical connector.
- Connect the fuel injector wiring harness electrical connector to the ECT sensor.
- Install the coolant crossover pipe. Refer to
Engine Coolant Crossover Pipe Replacement.
- Install the valve rocker arm covers. Refer to
Valve Rocker Arm Cover Replacement - Left Side and
Valve Rocker Arm Cover Replacement - Right Side.
- Install the upper intake manifold. Refer to
Upper Intake Manifold Replacement.