Intake Manifold: Description and Operation

DESCRIPTION

Upper Intake Manifold





The upper intake manifold is an injection molded nylon composite design. The upper intake manifold is sealed to the lower intake manifold using six individual press-in-place port silicone gaskets. Replace the gaskets whenever the upper intake manifold is removed from the engine. There is a silencer pad positioned between the upper and lower intake manifolds for improved noise, vibration and harshness (NVH). The left cylinder head cover has two alignment posts to aid proper installation of the silencer pad. The seven upper intake manifold fasteners thread directly into the composite lower intake manifold and are a self-taping design. If the upper intake manifold is damaged or cracked, it must be replaced.

The Electronic Throttle Control (ETC) and Manifold Air Pressure (MAP) sensor are attached directly to the upper intake manifold. The upper intake manifold also provides vacuum ports for brake booster, positive crankcase ventilation (PCV) and emissions control.

Lower Intake Manifold





The lower intake manifold is an injection molded nylon composite design. The lower intake manifold is sealed to the cylinder heads using six individual press-in-place port silicone gaskets. Replace the gaskets whenever the lower intake manifold is removed from the engine. The seven upper intake manifold fasteners thread directly into the composite lower intake manifold and are a self-taping design.

The fuel injection fuel rail is also a composite design. The four fuel rail fasteners thread directly into the composite lower intake manifold and are a self-taping design. The lower intake manifold can be serviced without removing the fuel injector rail. The fuel rail and fuel injectors must be installed into the lower intake manifold as an assembly. Do not attempt to install the fuel rail when the injectors are in the manifold. Always install new O-rings on the fuel injectors.

If the lower intake manifold is damaged or cracked, it must be replaced.