To change the upper Intake Manifold, start by gently removing the throttle body air inlet duct and draining the engine coolant from the cooling system. Confirm that the spark plug wire and the evaporative emissions canister purge solenoid wire harness connectors are broken. Mild the fuel pressure and take off the
Fuel Rail. Disconnect the brake booster hose from the vacuum source manifold on the upper Intake Manifold and the egr valve wiring harness heat shield nut with its bolt as well as the egr shield. Then, remove the throttle body support bracket bolts and support bracket, disconnect the map sensor electrical connector, and then remove the upper Intake Manifold bolts and stud. Clean the bolt threads on the upper Intake Manifold and remove the upper Intake Manifold right alongside the upper-to-lower Intake Manifold carrier gasket. In case one has to change the upper Intake Manifold, get rid of throttle body and vacuum source manifold as well. For installation, if it's the upper Intake Manifold, install the source of vacuum manifold first and then the throttle body. Install the upper to lower Intake Manifold carrier gasket onto the upper Intake Manifold as well as install the upper Intake Manifold onto the lower Intake Manifold with the correct dimension and then install the upper Intake Manifold. Apply thread lock compound gm p/n 12345382 or equivalent on the bolt threads and install upper Intake Manifold bolts (1-10) and tighten them in order to 10 nm (89 inch lbs.). Connect map sensor's electric connector, put on the throttle body support bracket and bolt it according to 98 nm (78 inch lbs). Install the egr shield and the egr valve wiring harness heat shield nut and bolt, tightening at 10 nm (89 inch lbs), and install the brake booster hose to the vacuum source manifold from the upper Intake Manifold. Replace the Fuel Rail, then attach the evaporative emissions canister purge solenoid valve wiring harness connector, then put back the right (rear)
Spark Plug Wires. Lastly, reinstall this fuel injector sight shield, fill the cooling system up with engine coolant, make careful entry with the throttle body air inlet duct, check for appropriate fluid levels and any fluid or vacuum leaks.