How to Change an Intake Manifold on a 5.3 Vortec Chevyby Cayden Conor
When you remove the intake manifold on the 5.3-liter Vortec Chevrolet, you should remove it as an assembly, along with the throttle body, fuel injectors and fuel injection rail. The intake has to be removed to replace the intake manifold gasket, which does crack and leak after some time. The leak will only get bigger, and cause the engine to run poorly if excess air is sucked in via vacuum, and oil will also leak out onto the engine.
Slide the drain pan under the radiator petcock. Loosen the petcock and allow the coolant to drain. If the coolant and drain pan is clean, and the coolant is less than five years old, you can reuse the coolant. Remove the PCV hose and valve by pulling it off the engine. Unplug the manifold absolute pressure sensor, then remove it, using the appropriate socket. Remove engine coolant air bleed clamp, using the screwdriver, then remove the hose from the throttle body.
Unplug the knock sensor. Remove the accelerator control cable bracket, using the appropriate socket. Remove the cable from the throttle body, using the screwdriver. Unscrew the fuel line from the fuel rail, using the appropriate line wrench. Remove the EVAP solenoid, its bolt and isolator, using the appropriate sockets.
Number the intake manifold bolts, using the marker in the following sequence: Starting on the passenger side front of the engine, number the bolts 10, 4, 1, 5 and 8. On the driver's side, starting at the front of the engine, number the bolts 7, 6, 2, 3 and 9. Number the head of the bolt and the intake manifold, so you know where each bolt goes.
Remove the intake manifold bolts, then lift the intake manifold off the engine. Clean the gasket-mating surfaces of the intake manifold and the head, using the plastic scraper and shop rags. If you are not reusing the intake transfer the throttle body and any sensors, including the MAP sensor and EVAP solenoid, from the old intake to the new intake. Number the bolt holes with the same numbers as on the old intake manifold.
Fit a new intake manifold gasket onto the engine. Set the intake manifold onto the gaskets. Apply a 0.20 inch band of threadlock on the threads of the intake manifold bolts. Tighten the bolts, in sequence, to 44 inch-pounds on the first pass, then on the second pass to 89 inch-pounds of torque.
Reinstall the PCV valve and hose. Reinstall the coolant air bleed hose and clamp onto the throttle body. Reinstall the accelerator control cable and its bracket. Tighten the bolts to 89 inch-pounds of torque.