Intake and Exhaust System (Supplementary Information: Turbocharger (TC))

Crankcase ventilation




1. Oil trap
2. Cylinder head inlet hose
3. Cylinder block inlet hose
4. Oil pan return connector
5. crankcase ventilation hose
6. PTC-nipple
7. Vacuum hose
The crankcase gases are removed from the cylinder block and to a certain extent the cylinder head to the flame trap (1) where the oil is separated from the gases and returned to the oil pan. The pressure differences between the upper and lower sections of the engine are equalized by the hose to the cylinder head.

When the turbocharger cuts in the crankcase gases pass through the PTC nipple (6) in the crankcase hose (5) to the fresh air intake.

When the engine is idling and lightly laden the vacuum in the fresh air intake in front of the turbocharger (TC) is missing and there is very little crankcase gas. Because of this a vacuum hose (7) is routed from the PTC nipple to a calibrated intake downstream of the throttle so that the crankcase gases are led directly to the intake manifold when lightly laden.

The PTC nipple is calibrated to give a controlled flow of crankcase gases. Power to the PTC nipple is supplied by the engine management system main relay and prevents water vapor in the crankcase freezing in the fresh air intake terminal which would otherwise occur at low temperatures.

The PTC nipple stabilizes at approximately 80°C just after the engine is started.