Q: How to remove the lower intake manifold on 2002 Chevrolet Express 2500?
A: To remove the lower Intake Manifold, disconnect first the battery negative cable and remove the engine cover. Drain the cooling system, then remove the retaining nut from the air cleaner outlet and disconnect the air cleaner outlet duct from the Throttle Body assembly. Remove the connector harness of the intake air temperature (IAT), loosen the air cleaner outlet duct from the intake air (IAF) sensor, and eliminate air cleaner outlet duct and assembly. First, strip off the accelerator control cable and cruise control cable from the throttle shaft and bracket, the PCV Valve Hose assembly from the Intake Manifold, and the valve rocker arm cover. Then, unplug all electrical connectors for throttle position (TP) sensor , idle air control (IAC) motor , engine coolant temperature (ECT) gauge sensor , a/c high pressure switch if available, fuel meter body assembly connector , evap canister purge solenoid valve , and manifold absolute pressure (MAP) sensor . Also, disconnect the A/C Compressor clutch if so equipped, egr valve, engine coolant temperature (ECT) sensor. Pull out the ground wire from the stud in the water outlet, remove the radiator inlet hose, heater hose, and water pump inlet hose from the Intake Manifold. Remove the a/c vacuum hose and power Brake Booster Vacuum Hose from the Intake Manifold and then the power Brake Booster Vacuum Hose bracket and nut. Eliminate accelerator control cable bracket, evap canister purge solenoid valve, Distributor, and disconnect fuel supply from the rear of the Intake Manifold. After that, relocate the ignition control module (ICM) and the spark plug wire harness retainer to EGR Valve inlet pipe, then take out the clamp bolt for the EGR Valve inlet pipe and disconnect it from intake and exhaust manifolds. To gain access to the front Intake Manifold bolt, disconnect the auxilary evaporator tube from the A/C Compressor if equipped, drive belt, loosening the nut for the power steering pump rear bracket. First remove the bolts and nut for the power steering pump mounting bracket and the A/C Compressor and power steering pump stays on the bracket then slide the power steering pump bracket outward. Take off the engine coolant temperature (ECT) sensor wire connector out of the engine wiring harness bracket and so on the lower Intake Manifold bolts. The Intake Manifold can be removed in a package; do not remove specific components unless service is required and spare dirt or debris from getting into the fuel system. Clean all surfaces of sealing as well as the Intake Manifold and if required continue with the disassembly of the Intake Manifold. Lastly, pull out the bottom Intake Manifold gaskets and throw them away.