Intake Manifold: Description and Operation

Intake and Exhaust Manifolds, and Components




The one-piece intake manifold incorporates a number of revisions:

- Integral coolant heated part load breather

- Accommodation for the new electronic EGR valve at the top of the manifold

- Revised EGR pipe connection at the bottom of the manifold

- Deletion of the separate idle air control valve orifice.

Intake Manifold - SC Engine




A new intake manifold, with an integral intercooler, is introduced for the SC engine. The manifold is attached to the cylinder head in the same way as the manifold for NA engines.

Throttle Body




The new throttle body integrates the idle air control valve (IACV) and the base idle channel. The base idle is set during manufacture and is not field-serviceable. A single track nonadjustable throttle posit on sensor (TPS) is mounted on the throttle body. Refer to Powertrain Management for operating information.

Air Cleaner And Intake

Minor air cleaner and intake modifications have been made to accommodate the new mass air flow sensor (MAFS) and improve intake tuning.

Air Cleaner




The location lugs are enlarged to accommodate the new mass air flow sensor of the EMS. The surface texture of the cleaner casing is revised to improve appearance. A new intake duct positions the air intake immediately behind the left headlamp housing, to eliminate water ingress.
On the SC engine the base of the air cleaner is revised to accommodate minor changes to the position of the mass air flow sensor and the air injection pipe.

Exhaust Manifolds




To improve sealing, seven studs secure each manifold in position, instead of four as previously. A new gasket is introduced to accommodate the revised fixing arrangement. On the NA engine of North American vehicles, the rear exhaust manifold is revised to replace the EGR valve mounting provisions with a connection for the EGR transfer pipe.

Intake Manifold Component Cover




A streamlined finisher covers the intake manifold components and fuel rail to provide enhanced underhood appearance.

Exhaust Gas Recirculation










An electronically controlled EGR system has been introduced with improved piping between the exhaust and intake manifolds. The electronic EGR valve (EGRV) replaces the previous vacuum solenoid and vacuum valve arrangement. Refer to Powertrain Management for operating information.