INTRODUCTION - CRANKCASE VAPOUR/GAS RECIRCULATION SYSTEM

1.4 16v

OPERATION

The oil vapours coming from the crankcase go as far as the cylinder head and are then directed into two different intakes:

- with the accelerator throttle opening medium-high, the vapours are drawn in by the duct immediately downstream of the air filter (1);

- with small throttle openings (and, in particular, with the engine idling or in deceleration conditions) the vapours are drawn in downstream of the throttle via the pipe (2).

1.9 JTD 16v

SPECIFICATIONS

Function

The oil vapour emissions are controlled by means of an oil separator (1) which collects the vapours coming from the crankcase (2) and from the tappet cover (3). The condensed vapours return to the sump, via a pipe, whilst the uncondensed vapours are sent, via a pipe (5) to the turbocharger air inlet hose.

1 - Oil separator

2 - Oil vapour outlet from the crankcase

3 - Oil vapour outlet from the tappet cover

4 - Condensed vapour sump return

5 - Inlet vapour delivery pipe

6 - Regulation valve

There is a regulation valve (6), on the inlet vapour delivery pipe (5), with a spring that in normal conditions acts on a diaphragm keeping it open, thereby allowing the flow of oil vapours coming from the oil separator.

When the vacuum inside the pipe (5) overcomes the calibration of spring, the diaphragm moves thereby closing the duct from the oil vapour separator preventing the intake of oil from the sump.

1.9 JTD 8v

SPECIFICATIONS

Function

The oil vapour emissions are controlled by the pipe (4) which collects the vapours escaping from the crankcase and the tappet cover (1) and ensures their partial condensation.

The vapours that are not condensed are sent, via the pipe (5), to the turbocharger air intake hose (3).

1 - Tappet cover

2 - Turbocharger

3 - Corrugated hose

4 - Oil vapour recovery pipe

5 - Oil vapour recirculation pipe

The regulation valve in the tappet cover that consists of a spring (1) and a diaphragm (2) prevents faulty intake phenomenon occuring.

When the vacuum values inside the tappet cover exceed a recommended limit, the diaphragm moves downwards sealing the duct from the crankcase.

1.4 16v TJet

CONSTRUCTION SPECIFICATIONS

The system is design to decant and burn the breather gases from the cylinder block/crankcase. These gases are made up of a mixture of air, fuel vapours and lubricant oil vapours.

The gases coming from the crankcase rise to the cylinder head and are then directed to a separator (1) which has a diaphragm which allows:

- the condensation and collection of the vapours

- the absorption of the vapours in the intake circuit for their combustion.

The system is equipped with a pipe (2) for the intake of vapours connected to the air chamber and a pipe (3) connected to the turbocharger intake.

This makes it possible to:

- during supercharging, send the vapours via the duct (3) to the turbocharger intake

- during idling or release, send the vapours to the duct (2) connected to the air chamber, downstream of the throttle.

1. Separator

2. Vapour supply pipe at idle speed

3. Vapour supply pipe at supercharging speed

4. Air chamber

5. Turbocharger air intake hose

Vapour separator

1. Connection to air chamber

2. Connection to turbocharger intake hose

3. Flow switching diaphragm

4. Vapour condensation cones

5. Condensed vapour collection on cylinder head