Engine management system - Td5 (Intercooler): Description and operation

The turbocharger is exposed to extremely high operating temperatures (up to 1,000 °C (1832 °F)) because of the hot exhaust gases and the high speed revolution of the turbine (up to 150,000 rev/min). In order to resist wear of the turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings cool. Oil is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo connections. Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the turbocharger assembly.

A heatshield is attached to the left hand side of the engine to protect adjacent components from the heat generated at the turbocharger. The heatshield is attached to the engine by two bolts an additional bolt attaches the heatshield to the turbocharger casting.

The engine control module controls the amount of boost pressure the engine receives by way of the turbocharger. When full boost is reached a control signal is sent to the wastegate modulator, and a vacuum is applied to the wastegate valve. The wastegate valve opens, bypassing some of the exhaust gas away from the turbine to be output to the exhaust system.

The engine should be allowed to idle for 15 seconds following engine start up and before the engine is switched off to protect the turbocharger by maintaining oil supply to the turbine bearings.

Intercooler

The intercooler is an air-to-air heat exchanger which lowers the intake air temperature to obtain a higher air density for better combustion efficiency. The intercooler receives compressed air from the turbocharger via a metal pipe; it cools the intake air via the intercooler matrix and delivers it to the intake manifold by means of a rubber hose which connects between the intercooler outlet and the intake manifold outlet. The rubber hose is connected to ports at each end by metal band clips. COOLING SYSTEM - Td5, DESCRIPTION AND OPERATION, Description.

The intercooler is located at the front of the engine bay, forward of the radiator.