GM 89017272
Intake Manifold

Initial steps to replace the upper Intake Manifold require a negative cable battery disconnect and sight shield removal alongside air cleaner intake duct removal. First remove and set aside the Spark Plug Wires installed on the engine's right side. Disconnect the manifold vacuum source before you depressurize the fuel lines then remove the Fuel Rail. Begin by uninstalling the egr heat shield then move to disconnect the cable bracket from the cylinder head mounting bolt and remove the accelerator cable. Follow these steps to properly remove the upper Intake Manifold and its gasket: remove the throttle body support bracket and the upper Intake Manifold bolts using a sequence for proper tightening. Begin installation by placing the new upper Intake Manifold gasket followed by upper Intake Manifold reinstallation using bolt torques set to 10 nm (89 inch lbs.) in the specified sequence. The install process requires the throttle body support bracket along with the accelerator cable and cable bracket to get installed onto the cylinder head mounting bolt. Reinstall the egr heat shield followed by the Fuel Rail then manifold vacuum source before you connect the spark plug wire(s) to the right side of the engine. The last step requires reinstalling both the air cleaner intake duct and fuel injector sight shield and then reconnecting the negative Battery Cable.

Start by disconnecting the battery ground negative cable before continuing with upper Intake Manifold and left and right valve Rocker Arm cover removal and disconnecting the engine coolant temperature (ECT) wiring harness Fuel Injector and manifold air pressure (MAP) wiring harness and fuel pipes. First detach the fuel pipe clip bolt followed by the Fuel Injector rail until you can relocate the Power Steering Pump out of the way. Follow this order for disassembly: disconnect the heater inlet pipe, radiator inlet hose, thermostat bypass hose and ect sensor followed by water outlet, thermostat and lower Intake Manifold bolts extraction which allows removal of the lower Intake Manifold. The valve rocker arms and pushrods need removal for cleaning the gasket and seal surfaces which exist on the engine block, cylinder heads and lower Intake Manifold. When installing the new lower Intake Manifold gaskets it is necessary to reinstall the valve rocker arms and pushrods before applying sealant gm p/n 12345739 to the engine block-to-lower Intake Manifold mating surface. Place new lower Intake Manifold bolts into position before applying sealer gm p/n 12345382 to the lower Intake Manifold bolt threads. Tighten bolts by following the specified torque order. Reassemble all components by joining the heater inlet pipe to the Thermostat and water outlet bolts and ect sensor while applying proper torque to the ect sensor. After reconnecting the Thermostat bypass hose and radiator inlet hose as well as the heater inlet pipe you can reinstall the Power Steering Pump while connecting the fuel return and feed pipes to the Fuel Injector rail. Reinstall the right and left valve Rocker Arm covers and upper Intake Manifold while connecting the fuel pipe clip and bolt followed by connecting the Fuel Injector and map wiring harness and the ect wiring harness and finally reconnecting the battery ground (negative) cable.

Clean and inspect the upper intake manifold and the lower intake manifold mating surface.

Reinstall the air cleaner intake duct, throttle body support bracket, and its bolts, tightening them to 10 Nm (89 inch lbs.).

The EGR tube to the intake manifold and then the thermostat housing.

First, remove the upper intake manifold, thermostat housing, and disconnect the electrical connector from the ECT.

Remove the generator and the drive belt tensioner, followed by the EGR valve outlet pipe.

Position a new throttle body gasket on the upper intake manifold, install the throttle body, and secure it with nuts tightened to 10 Nm (89 inch lbs.).

Remove the upper intake manifold bolts and stud, clean the bolt threads, and lift the back of the upper intake manifold to slide it forward from the throttle body support bracket.

Detach the radiator inlet hose from the water outlet housing.

First, remove the upper intake manifold.

The brake booster hose.

Inspect the flatness of the inlet flanges and clean the mating surfaces of the lower intake manifold, as well as the bolts and bolt holes of any adhesive compound.

Install the ECT sensor, followed by the thermostat, gasket, and water outlet housing, tightening the water outlet housing bolts to 27 Nm (20 ft. lbs.).

Apply sealant to the threads of the bolts and install new lower intake manifold bolts.

Take off the camshaft position (CMP) sensor wiring harness, left side spark plug wire harness, and engine wiring harness.

Install the lower intake manifold and bolts, tightening them in sequence to specified torque values.

Reinstall the power steering pump, then install the fuel injector rail assembly without pressing on the fuel pressure regulator valve.