Captiva

Engine Component Description

The cylinder hollow frame structured 4 cylinder in-line. The block has 5 crankshaft bearings with the thrust bearing located on the third bearing from the front of the engine.

The crankshaft is a steel crankshaft. It is supported in 5 main journals with main bearings which have oil clearance for lubricating. The 3rd bearing of the 5 main bearings is the thrust bearing whose the crankshaft has properly axial end play.

The oil pump is a rotor pump located in the crankshaft balancer and driven by the balance shaft. The oil pump draws engine oil from the oil sump and feeds it under pressure to the various parts of the engine. At high engine speeds, the oil pump supplies a much higher amount of oil than required for lubrication of the engine. The oil pressure regulator prevents that too much engine oil is entering the lubricating passages.

The pistons are aluminium pistons with top land. The connecting rods are fractured steel connecting rods with bushing. The piston pin is floating the connecting rod bore.

This cylinder head is double over head camshaft (DOHC) type and has 2 camshafts that open 4 valves per cylinder with tappets. The cylinder head is made of cast aluminium alloy for better strength in hardness with light weight.

Intake and exhaust camshaft are connected to each other with gears. The intake camshaft has a camshaft sprocket which is driven by the timing chain. The valve actuation occurs by hydraulic tappets and valve rocker arms which are located between cam and valve stem. The valve clearances are self adjusting.

The intake manifold is the air flow passage to the cylinder combustion chamber through the throttle body and has an effect on engine torque, power, noise, driveability, emission, fuel economy and performance. The intake air amount is regulated by vacuum controlled flaps.

The exhaust manifold is located to the cylinder head and send the turbocharger the exhaust gas out of the combustion chamber. It is designed to endure on high pressure and high temperature.

The turbocharger is located between exhaust manifold and exhaust particulate filter. It consists of an exhaust gas turbine and a fresh air turbine which are connected to each other by a rod. The exhaust gas turbine is driven by the exhaust gas and the fresh air turbine is driven by the exhaust gas turbine. The fresh air turbine creates compressed air which is cooled down in the charger air cooler. The charge air cooling increases the air density. The cooled, compressed air is discharged under pressure to the engine. The turbocharger has a vacuum controlled variable turbine geometry which modulates the charge pressure to the engine speed and load.

The recirculation of exhaust gas to the combustion chamber causes a reduction of NOx - emissions. The reduction of exhaust gas emissions can be increased by the cooling of the recirculating exhaust gas. Therefor a exhaust gas recirculation cooler with exhaust gas recirculation valve is located between exhaust manifold and cylinder head.

The engine is equipped with a common rail direct injection system. A high pressure fuel pump, driven by the intake camshaft discharges the fuel to the fuel rail, where the fuel is stored with pressure up to 1800 bar (26107 psi). The fuel is injected by electronic controlled fuel injectors direct to the combustion chamber.