GM 12567679
Intake Manifold

To remove the lower Intake Manifold, one should first remove the negative Battery Cable and breather at the air cleaner outlet duct along with their respective retaining wingnut, and disconnect the iat sensor harness connection. Next, remove the air cleaner outlet duct from Throttle Body, the accelerator cable from Throttle Body and the accelerator control cable bracket as well as disconnect the cruise control cable from throttle shaft and accelerator cable bracket if so equipped. Remove the vacuum hose from the Intake Manifold if built in a/c, from the power Brake Booster Vacuum Hose, and drain the cooling system. Unbolt the radiator inlet hose, heater hose, and water pump inlet hose from the Intake Manifold. Remove the fuel meter body assembly, evap canister purge solenoid valve, manifold air pressure (MAP) sensor, exhaust gas recirculation (EGR) valve, ignition coil, ignition control module (ICM), generator, idle air control (IAC) motor, throttle position (TP) sensor, a/c compressor cutoff switch if available and a/c clutch switch if available, and engine coolant temperature (ECT) sensor. Unclip the engine wire harness clips, pull the harness out of the way, and unsecure the accelerator cable bracket from the Throttle Body and Intake Manifold but leave the cables connected to the bracket. Loose the pcv hose assembly from the Intake Manifold and valve rocker arm cover, the evap canister purge solenoid valve, and the sparkplug wire harness retainer off the EGR Valve inlet pipe. Unscrew the clamp bolt that's connected to the egr inlet pipe and pull the pipe away from the intake and exhaust manifolds, and the Distributor. One must disconnect the fuel supply and return pipes that are located behind the Intake Manifold while avoiding the discharge of the refrigerant. To access the rear left front bolt for the Intake Manifold, remove the Drive Belt, loosen the nut for the power steering pump rear bracket, secondary air injection (AIR) reactor pipe bracket nut if equipped, nut of the power steering pump rear bracket and in the front of the engine. Smack the bolts and nut on the power steering pump mounting bracket while you flip off at the a/c compressor and chat along with power steering pump still on the bracket, then scoot the bracket laying on the bracket eradicate to the bolt up front achieve on the Intake Manifold. Unplug the ect sensor wire connector if available, and unbolt the lower Intake Manifold bolts. The Intake Manifold can also be taken out as an assembly; do not remove specific component unless service is required and do not let dirt or debris enter it the fuel system. Unscrew and remove the lower inlet manifold gaskets and clean the entrance manifold in cleaning solvent, and dry with compressed air at the same time checking the condition of the gasket sealing surfaces and restricted egr system passages , restricted cooling system passages , cracks, or damage, and damaged to keened threaded bolt holes respectively. Replace if needed, and use a 4.0 mm (0.157 inch) patch of adhesive gm p/n12346141 or equivalent on each end of the cylinder head of the lower Intake Manifold gasket while wet. Mount the lower Intake Manifold gaskets onto the cylinder head using the gasket locator pins and apply gm p/n 12346141 or equivalent adhesive at a 5mm (0.197 inch) wide bead size to the top of the front and rear engine block with the adhesive bead extending 13mm (0.50 inch) onto each lower Intake Manifold gaskets. Mount the lower Intake Manifold on the engine block, and apply threadlock gm p/n 12345382 or equivalent if you are going to reuse the lower Intake Manifold bolts and install the bolts. Follow the right tightening sequence and specifications for torque. First pass to 3 nm (27 inch lbs.), second pass to 12 nm (106 inch lbs.) and final pass to 15n.m (11 ft. Lbs.). Mount the power steering pump mount bracket loosely and bolt with nuts and tighten to 41 nm (30 ft. Lbs.). Install the air reactor pipe bracket nut where fitted, it should be tightened to 41 nm [30 ft. Lbs.] then install the Drive Belt, fuel supply and return pipes, with a correct positioning of the engine to number one cylinder top dead center for Distributor installation. To mark the position of the crankshaft balancer, remove the number one Spark Plug, rotate the crankshaft to the compression stroke, align the reference marks of the crankshaft balancer with the alignment marks of the front cover, and reinstall the number one Spark Plug together with the Distributor. In the evap canister purge solenoid valve: install EGR Valve inlet pipe to the intake and exhaust manifolds, tighten nut for Intake Manifold 25 nm (18 ft. Lbs.), in exhaust manifold tighten nut 30 nm (22 ft. Lbs), and clamp bolt 25 nm (18 ft. Lbs). Reconnect both the Spark Plug wire harness retainer, pcv hose assembly, accelerator cable and cruise control cable bracket to the Throttle Body, with nuts tightened to 9 nm (80 inch lbs.) nuts and both the accelerator cable bracket to the Intake Manifold and Throttle Body, with studs and nuts tightened to 12 nm (106 inch lbs.). Mount the engine wiring harness, install the clips, hook up the iac motor ,tp sensor, a/c compressor cutoff switch if necessary, a/c clutch switch if necessary, ect sensor ,fuel meter body assembly, evap canister purge solenoid valve, map sensor, egr valve, ignition coil, icm, and generator. On our minivan we also connected the Brake Booster Vacuum Hose, vacuum to intake if we had a/c, water pump inlet hose, heater hose, and radiator inlet hose. Cruise control cable if we have it and accelerator cable to the Throttle Body making sure that the cable would seat correctly. Carefully install the air cleaner outlet duct to the Throttle Body and maf sensor, tightening hose clamp to 4 nm (32 inch lbs.), connect the iat sensor harness connector and leave air cleaner duct installed with retaining wingnut set to 2 nm (18 inch lbs.). Finally, join the breather tube to the air cleaner outlet duct, fill the cooling system, and reconnect the battery negative cable.

To replace the upper Intake Manifold, one should disconnect the breather tube at the outlet duct of the air cleaner; remove the outlet duct retaining wingnut; and disconnect the iat sensor harness connector. Next, you will pull off the air cleaner outlet duct from the Throttle Body, then pull off the accelerator cable from the Throttle Body and pull it from the accelerator control cable bracket. Deadline: if possible, remove the cruise control cable from the throttle shaft and the accelerator cable bracket, and also the vacuum hose of the vacuum tank and the power brake booster of the vacuum hose. Remove the electrical connector on the a/c compressor clutch , a/c compressor cutoff switch , throttle position (TP) sensor , idle air control (IAC) motor , fuel meter body assembly, manifold absolute pressure (MAP) sensor and evap canister purge solenoid valve . Take off the engine wire harness clip from the accel cable bracket; move away the engine wire harness; and take off the accel cable bracket from the Throttle Body and Intake Manifold. Take out the accelerator and cruise control cable bracket from the Throttle Body with leaving the cables to the bracket, then detach the PCV Valve Hose assembly from the Intake Manifold and valve rocker arm cover. Take off the bracket for the engine wiring harness from the Intake Manifold stud, from the fuel lines from the fuel meter body assembly, and from the evap canister purge solenoid valve. These cover grabbing and removing the studs and the upper Intake Manifold and removing upper Intake Manifold gasket and seal from the fuel meter body assembly discarding both gaskets. Clean all sealing surfaces and upper Intake Manifold interior using a shop towel and cleaning solvent and inspecting for cracks, damage, or loose threads. If replacing the upper Intake Manifold, unsnapping the power vacuum fitting from the brake booster tube and pcv valve cover, discard their seals. In the case of installation, begin with installing the Throttle Body and the MAP Sensor if disconnected, a subsequent installation of the pcv valve cover using a new seal lubricated with fresh clean engine oil, and secure it to its position. Replace the power brake booster vacuum tube fitting with a new seal and lubricate it, then lock it in. Install a new seal on the fuel meter body assembly, lubricate it, and put in a new upper Intake Manifold to lower Intake Manifold gasket in the groove of the upper Intake Manifold after which put the upper Intake Manifold onto the lower Intake Manifold. If reusing fasteners, apply threadlock gm p/n 12345382 or equivalent, to the threads of the upper Intake Manifold attaching bolts then install the upper Intake Manifold attaching studs, torquing the studs to 5 nm (44 inch lbs.) on the first pass and 9 nm (80 inch lbs.) in the final pass. Replace fuel lines, evap canister purge solenoid valve, then reinstall and tighten bracket for the engine wiring harness to the lower Intake Manifold stud with a nut to 12 nm (106 inch lbs). Attach the accelerator and cruise control cable bracket to the throat body with nuts that should be screwed to 9 nm (80 inch lbs), and add the accelerator control cable bracket to the Throttle Body and Intake Manifold, screwing the studs with nuts to 12 nm (106 inch lbs). Connect the PCV Valve Hose assembly, install the engine wiring harness to the position, and install the wire harness clip to the accelerator cable bracket. Reconnect the electrical connectors of the fuel meter body assembly ,map sensor ,evap canister purge solenoid valve,a/c compressor clutch,a/c compressor cutoff switch, throttle position tp sensor, and idle air control iac motor. Connect the vacuum hose from the vacuum tank into the vacuum system at the Intake Manifold, connect the power Brake Booster Vacuum Hose, and if so equipped, place the cruise control cable onto the throttle shaft and mounting bracket. Mount the accelerator cable onto the Throttle Body, making sure that it is correctly seated, and connect it to the accelerator cable control bracket. The matter of metering angle fuel sensor (MAF) should be handled carefully in order to avoid damaging it then the outlet duct for air cleaner is fitted to the Throttle Body and maf sensor and the hose clamp bound to 4 nm (32 inch lbs.). Connect the iat sensor harness connector, install the air cleaner outlet duct retaining wingnut and tighten it at 2 nm (18 inch lbs.), and finally connect the breather tube into the air cleaner outlet duct.

First dis-connect the neg. Battery cable and the breather tube at air cleaner outlet duct.then remove the air cleaner outlet duct to replace the lower Intake Manifold. Defeat the accelerator cable from the Throttle Body and keep it away from accelerator control cable bracket and followed by defeating the cruise control cable from throttle shaft and accelerator cable as well, if there's one. Remove the vacuum hose at the Intake Manifold if a/c is equipped, the power Brake Booster Vacuum Hose, and drain the cooling system. Disconnect the radiator inlet hose, hose leading to heater, and water pump inlet hose from the Intake Manifold. Cease the electrical connectors for fuel meter body assembly , evap canister purge solenoid valve,mapview sensor (MAP), ignition coil, ignition control module (ICM),generator, idle air control ( IAC ) motor, throttle position ( TP ) sensor, a/c compressor cutoff switch, a/c clutch switch, and engine coolant temperature ( ECT ) sensor. Cease the engine wiring harness clips and move the harness away and remove the accelerator cable bracket from the Throttle Body and Intake Manifold whiles keeping the cables connected. The pcv hose assembly must be removed from the Intake Manifold and valve rocker-arm cover, the evap canister purge solenoid valve and the Distributor. Remove the fuel supply and return hoses at the back of the Intake Manifold while avoiding the release of the refrigerant. To get access for left front bolt to the Intake Manifold, remove the Drive Belt, loosen and remove the power steering pump rear bracket nuts, and slide the power steering pump bracket front. Unplug the ect sensor wire connector, if available, and then unbolt the lower Intake Manifold bolts and Intake Manifold assembly, and dispose of the lower Intake Manifold gaskets. Clean the lower Intake Manifold with the cleaning solvent and dry it by compressed air checking on gasket sealing surfaces for damage or restricted cooling passages, cracks or damage to threading bolt holes. If a replacement was needed, use gm 4.0 mm (0.157 inch) patch of adhesive gm p/n 12346141 (Canadian P/N 10953433) or equivalent to the side of the Cylinder Head of the lower Intake Manifold gasket on each side, must be installed while the adhesive is still wet. Mount the lower Intake Manifold gasket on Cylinder Head using the gasket locator pins; apply a 5mm (0.197 inch) bead of adhesive gm p/n 12346141 (Canadian P/N 10953433) to the front and rear top of the engine block with bead running onto each lower Intake Manifold gasket. Mount the lower Intake Manifold on to the engine block and if bolts are re-used use thread lock gm p/n 12345382 (Canadian P/N 10953433) on the bolt heads, then tighten the bolts according to a predetermined sequence in a three-step sequence up to the specified torque values. Mount and loosely install power steering pump mounting bracket and tighten bolts and nuts at 41 nm (30 ft.blbs) and reinstall Drive Belt. Install the supply and return pipes of fuel while ensuring that the engine is at number one cylinder top dead center for fixing the Distributor. Remove the Spark Plug from the number one cylinder, turn Crankshaft to stop on the compression stroke, align the marks of reference, and re-install the Spark Plug and the Distributor. Replace the evap canister purge solenoid valve, pcv hose assembly, accelerator and cruise control cable bracket, tightening the nuts to specified torque values. Mount the engine wiring harness, attach the clips, and attach necessary electrical connectors. Attach the vacuum hose to the power brake booster, vacuum hose to the Intake Manifold if you have an a/c, and reinstall the water pump inlet hose, heater hose, and radiator inlet hose. If the vehicle comes with a cruise control cable, reinstall this particular cable, and then reinstall a cable that controls the accelerator on the Throttle Body making sure it is seated well, and attach the accelerator cable to the control bracket. Lastly, replace the air cleaner outlet duct, reconnect the breather tube, refill the cooling system, and reconnect the negative Battery Cable.

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.