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.

’K16 with VVC’

The alloy inlet manifold assembly comprises a manifold chamber bolted to the inlet manifold with a gasket interposed between the two components. The throttle housing is bolted to the manifold chamber and sealed with and ’O’ ring.

The manifold chamber incorporates the manifold absolute pressure sensor and brake servo vacuum hose union. The air intake temperature sensor is incorporated in the inlet manifold. The inlet manifold is attached to the cylinder head and sealed with a gasket. A strut between the inlet manifold and the cylinder block supports the inlet manifold assembly.

’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.

EXHAUST MANIFOLD

’K’ series engine

The 4 branch fabricated steel exhaust manifold terminates in a siamised front pipe flange. The heated oxygen sensor is located in the manifold at the rear and in the outlet for numbers 2 and 3 cylinders. The manifold flanges are sealed by gaskets.

’L’ series engine

The cast iron exhaust manifold carries an EGR valve and a variable wastegate Garrett turbocharger. There are two tappings on the compressor housing; the ’N’ port to the wastegate and the ’J’ port to the boost pressure sensor on the bulkhead.

NOTE: Gaskets are NOT fitted between the manifold to turbocharger joint or between the turbocharger to exhaust outlet pipe joint.