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

INLET MANIFOLD

’K’ Series engine

The inlet manifold is a one piece plastic moulding attached to the cylinder head with a gasket interposed between the 2 components. The throttle housing is bolted to the manifold chamber, sealing being effected by means of an ’O’ ring. The intake air temperature sensor is inserted at the rear just above the pipe flange.

’D’ Series engine

Up to 97.5 MY

The cast alloy inlet manifold is bolted to the cylinder head and is supported by a stay. It incorporates the manifold absolute pressure (MAP) sensor, the throttle body, the electronic air control valve (IAC) and the fuel injectors. Also incorporated is the tapping for the brake servo.

97.5 MY on

The plastic inlet manifold is bolted directly to the cylinder head and utilises an individual gasket for each inlet port and the coolant feed. The manifold also incorporates the fuel injectors, electronic air control valve (IAC) and the brake servo vacuum adaptor. The throttle body is bolted directly to the inlet manifold.

’L’ Series engine

The inlet manifold is manufactured from aluminium alloy and the gasket is a multi-leaf type which also seals the exhaust manifold.

On vehicles fitted with an intercooler, an intake air temperature sensor is located at the timing belt end to measure the temperature of the boosted air supply.

’T’ Series engine

The inlet manifold assembly comprises a manifold chamber bolted to the inlet manifold with additional support being provided by two brackets bolted to the inlet camshaft cover. The throttle housing is bolted to the inlet manifold chamber via a flexible mounting plate. The inlet manifold is bolted to the cylinder head and carries the fuel injectors and the intake air temperature sensor. Gaskets are used to seal the inlet manifold joint faces.