OEM GMC Sonoma Intake Manifold

GMC Sonoma Intake Manifold Parts Questions & Experts Answers

• Intake Manifold
  12567679
  Q: How to replace the upper intake manifold on GMC Sonoma?

  A: Begin upper Intake Manifold replacement by disconnecting the breather tube at the air cleaner outlet duct followed by removing the air cleaner outlet duct retaining wingnut and disconnecting the iat sensor harness connector. You must take the following steps to replace the upper Intake Manifold: remove the air cleaner outlet duct from the Throttle Body and disconnect the accelerator cable from the Throttle Body before removing it from the accelerator control cable bracket. Start by disconnecting the throttle shaft from the cruise control cable as well as the accelerator cable bracket. Then remove both the vacuum hose connecting the power brake booster to the vacuum tank and the vacuum tank hose itself if vehicle is equipped with these components. Disconnect power cables of the a/c compressor clutch and a/c compressor cutoff switch alongside the throttle position (TP) sensor and idle air control (IAC) motor and fuel meter body assembly and manifold absolute pressure (MAP) sensor and evap canister purge solenoid valve . First free the engine wire harness clip connected to the accelerator cable bracket and shift the engine wiring harness into place before extracting the accelerator cable bracket from its position between Throttle Body and Intake Manifold. First remove the Throttle Body's accelerator and cruise control cable bracket ensuring the bracket retains the cables before separating the PCV Valve Hose assembly between the Intake Manifold and valve rocker arm cover, and finally removing the engine wiring harness bracket fastened to the Intake Manifold stud. First remove fuel lines from the fuel meter body assembly and from the evap canister purge solenoid valve before finally removing studs and the upper Intake Manifold while discarding the upper Intake Manifold gasket and fuel meter body assembly seal. Remove all dirt from all sealing surfaces inside the upper Intake Manifold while inspecting the submerged parts for cracks and damages and loose threads. To replace the upper Intake Manifold, both PCV Valve cover seals and power brake booster vacuum tube fitting need replacement. First install the Throttle Body and MAP Sensor if you need to remove them before putting a new seal (O-ring) on the PCV Valve cover and oiling it with clean engine oil then securing the piece in position. Use this installation method twice for the power brake booster vacuum tube fitting by adding a fresh seal at each step. To complete the installation, insert a fresh seal onto the fuel meter body assembly followed by lubrication before placing a new upper Intake Manifold to lower Intake Manifold gasket in the groove of the upper Intake Manifold. Finally, install the upper Intake Manifold onto the lower Intake Manifold. Reused fasteners require thread-lock gm p/n 12345382 or equivalent which must be applied to the upper Intake Manifold attaching bolts before installation. The attaching studs should be tightened first to 5 nm (44 inch lbs.), then to 9 nm (80 inch lbs.). Put back the fuel lines followed by the evap canister purge solenoid valve and engine wiring harness bracket before tightening the nut to 12 nm (106 inch lbs.). First position the accelerator and cruise control cable bracket to the Throttle Body and Intake Manifold before tightening the studs and nuts to 12 nm (106 inch lbs.). After installing the PCV Valve Hose assembly you should place the engine wiring harness before attaching the wire harness clip. Rejoin the electrical connectors that service the fuel meter body assembly as well as the MAP Sensor , evap canister purge solenoid valve , a/c compressor clutch , a/c compressor cutoff switch , tp sensor , and iac motor . Move on by connecting the vacuum hose from the vacuum tank to the Intake Manifold, installing the power Brake Booster Vacuum Hose while also attaching the cruise control cable to its throttle shaft and bracket. Following proper seat alignment of the Throttle Body position the accelerator cable then route it to the accelerator cable control bracket. Screw the air cleaner outlet duct to the Throttle Body where it meets the maf sensor while tightening the clamp to 4 nm (32 inch lbs.). Install the iat sensor harness connector and tighten the retaining wingnut to 2 nm (18 inch lbs.). You should complete the installation by connecting the breather tube to the air cleaner outlet duct.