Manifold & exhaust systems (Inlet manifold): Description and operation

INLET MANIFOLD

’K’ Series Engine

The inlet manifold is a one piece plastic moulding which is attached to the cylinder head on three locating studs and nuts and further retained by four bolts. A rubber moulded gasket, which is located in a corresponding recess in the inlet manifold mounting face, seals the manifold to the cylinder head.

The inlet manifold has vacuum take-off points for the fuel pressure accumulator, the brake servo, the engine control module and the purge valve. A further take-off vents the camshaft cover into the inlet manifold.

Two threaded lugs on the inlet manifold provide for the attachment of the fuel rail. Four ports at the base of each inlet tract house the injectors which are sealed to the manifold with O-ring seals and retained in position by the fuel rail.

The Idle Air Control (IAC) valve is attached to the inlet manifold, adjacent to the throttle housing and is secured with four Torx bolts and sealed to the manifold with an O-ring seal.

The throttle housing is attached to the left hand end of the inlet manifold and is secured with four bolts and sealed with an O-ring seal. The Intake Air Temperature (IAT) sensor is mounted in No.4 inlet tract.

’L’ Series Engine

The inlet manifold is a one piece aluminium alloy casting. The inlet manifold is attached to the cylinder head with four bolts and two nuts. A metal laminated gasket seals the inlet manifold to the cylinder head. The same gasket also seals the exhaust manifold to the cylinder head.

An Intake Air Temperature (IAT) sensor is located in the left hand end of the inlet manifold. An air inlet port on the top face of the inlet manifold mates with the plenum chamber. The Exhaust Gas Recirculation (EGR) cooler pipe is attached to the plenum chamber. A paper gasket seals the plenum chamber to the inlet manifold and the EGR cooler pipe to the plenum chamber.