GM 12580250
Intake Plenum

The first step for Intake Manifold replacement requires complete removal of the Fuel Rail system. You need to loosen the plenum duct clamp at the Intake Manifold front then remove the 10 bolts holding the Intake Manifold to the cylinder heads. Remove the Intake Manifold by lifting it upward starting from the back end while conducting inspection and cleaning of the components. The inside edge of rubber plenum duct requires light lubrication while removing debris from the cylinder heads and Intake Manifold before you install new gaskets on the Intake Manifold. Coordinate the installation of the Intake Manifold by tightly securing the PCV Valve Hose to its fitting at the rear portion. Place the Intake Manifold front end inside the plenum duct before lowering the rear section onto the cylinder heads. Begin by installing the Intake Manifold bolts loosely onto the cylinder heads but apply torque in a sequential order (1-10) reaching 10 n.m (89 lb in). Tighten the plenum duct clamp at the front of the Intake Manifold to 2.25 n.m (20 lb in). Check for fuel leaks by cycling the ignition through on for 2 seconds then off for 10 seconds before returning to on. Reinstall the Fuel Rail assembly before this check. The conclusion of this installation effort involves placing and securing the fuel injector sight shield.

First, you will have to remove the Fuel Rail assembly and loosen the plenum duct clamp near the front of the Intake Manifold in order to change it. Then, unbolt the 10 bolts holding the Intake Manifold to the cylinder heads and raise the Intake Manifold up and off the rear. Clean and check the Intake Manifold before lightly lubing the in side of the rubber plenum duct and quickly cleaning any de tritus in the Cylinder Head and Intake Manifold. New gaskets to the Intake Manifold while doing all to ensure that the PCV Valve Hose is well connected to the fitting at the back before putting the Intake Manifold. Mount the front side of the Intake Manifold into the plenum duct and position the rear onto the cylinder heads. Loosely install the 10 bolts you use to join the Intake Manifold to the cylinder heads, tighten aroun the bolt using a torque wrench apply 10 nm (89 inch lbs.) inch lbs. Start with bolt number 1 and go to bolt number 10 in sequence. Make sure that the plenum duct is correctly fitted to the front of the Intake Manifold and tighten plenum duct clamp to 2.25 nm (20 inch lbs.). Replace the Fuel Rail assembly and turn the ignition key on for 2 seconds and off for 10 seconds. Turn on the ignition back, and inspect for fuel leaks prior to the installation of the fuel injector sight shield.