CRANKCASE VAPOUR/GAS RECIRCULATION SYSTEM

Description 1080D

1.2 8v

The evaporation emission control system prevents fuel vapours emerging into the atmosphere from the tank.

Fuel vapours from the tank are conveyed through this system into an active carbon container, where they are absorbed.

When the engine is running, a controlled intake of environmental air regenerates the active carbon. Fuel vapours are thus extracted and directed to the engine as a result of a command from the engine control unit.

The system controls crankcase emissions of vent gases consisting of mixtures of air, fuel vapours and burnt gases that leak through the piston rings and also lubricant oil vapours by redirecting them back to the engine so they can be burnt.

Blowby gases from the crankcase rise to the cylinder head and are conveyed to two different intakes:

• with medium-high accelerator throttle openings, the gases are taken in through the port immediately downstream from the air cleaner (1).
• with small throttle openings (particularly when the engine is idling or in over-run), gases are taken in downstream of the throttle (2).

1.6 16v

CONSTRUCTION FEATURES

During engine operation, the oil vapours and the gases which escape through the piston seals into the crankcase are collected by a special system.

OPERATING

Some of the oil vapours, condensed, drop back into the crankcase; the remaining vapours are sent to the intake through pipes (2) and (5).

At idle speed, the oil vapours flow through the pipe (5); at higher engine loads through the pipe (2). There is a spark out (1) inside the pipe (2) to prevent combustion due to flame returns from the butterfly casing (4).

1, Spark out

2, Main exhaust gas recirculation pipe

3, Air filter - butterfly casing connecting hose

4, Butterfly casing

5, Idle speed exhaust gas recirculation pipe

6, Calibrated port

1.3 JTD 16V

Function

The oil vapour emissions are controlled by an oil separator (1) which collects the vapours released from the crankcase and from the tappet cover via the pipe (2). The condensed vapours pass through a pipe (3) returning to the sump, whilst the uncondensed vapours pass through a pipe (4) and are sent to the turbocharger air intake hose.

1 - Oil separator

2 - Oil vapour outlet from cover

3 - Return to the sump of condensed vapours

4 - Intake vapour pipe

1.9 JTD 8V

CONSTRUCTION FEATURES

The oil vapour emissions are controlled by a separator (1) which collects the vapours released from the crankcase using the pipe (2).

The difference in temperature between the separator and the oil vapours causes partial condensation.

The uncondensed vapours are sent, through a pipe (3), to the turbocharger air inlet hose.

CONSTRUCTION FEATURES

A regulating valve on the rocker cover, consisting of a spring (1) and diaphragm (2), prevents faulty intake phenomena.

When the vacuum values present under the rocker cover exceed a specified limit, the diaphragm moves downwards and blocks the pipe coming from the crankcase.

1.6 16v · BIPOWER

During engine operation, the oil vapours and the gases which escape through the piston seals into the crankcase are collected by a special system.

OPERATION

Some of the oil vapours, condensed, drop back into the crankcase; the remaining vapours are sent to the intake through pipes (2) and (5).

At idle speed, the oil vapours flow through the pipe (5); at higher engine loads through the pipe (2). There is a spark out (1) inside the pipe (2) to prevent combustion due to flame returns from the butterfly casing (4).

1, Spark out

2, Main exhaust gas recirculation pipe

3, Air filter - butterfly casing connecting hose

4, Butterfly casing

5, Idle speed exhaust gas recirculation pipe

6, Calibrated port

1.4 8v

SPECIFICATIONS

The system controls the emission from the crankcase of lubricant oil vapours which rise to the cylinder head. There is a special pipe from the tappet cover that directs the lubricant oil vapours immediately downstream of the air filter so that they can be drawn in and burnt in the combustion chamber.

1. Oil vapour inlet hose

2. Throttle body