Crankcase Ventilation (S80)
To counteract the risk of freezing in the crankcase ventilation pipe, on turbocharged engines, it has been equipped with engine coolant heating. The heating is achieved by the coolant pipe being laid parallel to the crankcase ventilation pipe. The pipes have a common insulated sleeve.
The heated coolant comes from the rear of the engine. The coolant pipe inlet is connected to the engine using a banjo coupling. The coupling hole diameter is calibrated so that the removal of the coolant should not affect the engines normal coolant flow.
The return coolant flows via a rubber hose to the coolant pump inlet pipe at the rear of the engine.
To ensure that there is always negative pressure in the crankcase ventilation, the hose connection at the flame trap has been equipped with an extra suction pipe. At the other end this extra suction pipe is connected to the engine intake manifold with a banjo coupling. The banjo coupling hole diameter is calibrated so that the negative pressure in the flame trap is maintained by the vacuum in the engine intake manifold. After that the vacuum is taken from the turbocharger fresh air intake terminal.