Charge Air Cooling: Notes
The N63 engine was the first BMW engine to use indirect charge air cooling; this has now also been adopted for the N74 engine. The heat is extracted from the charge air by means of an air to coolant heat exchanger. This heat is then released to the ambient air across a coolant to air heat exchanger. To achieve this, the charge air cooling has its own low-temperature cooling circuit. This is independent of the engine cooling circuit.
N74 Cooling Circuit for Charge Air Cooling
INDEX EXPLANATION REFERENCE CHART
| Index | Explanation |
|---|---|
| 1 | Radiator for charge air cooling |
| 2 | Electric coolant pump for charge air cooling |
| 3 | Engine control unit |
| 4 | Expansion tank |
| 5 | Charge-air cooler |
N74 Air Intake and Exhaust System
INDEX EXPLANATION REFERENCE CHART
| Index | Explanation |
|---|---|
| 1 | Unfiltered air intake |
| 2 | Unfiltered air pipe |
| 3 | Unfiltered air resonator |
| 4 | Connection for crankcase ventilation, charged operation |
| 5 | Intake silencer |
| 6 | Intake manifold |
| 7 | Charge-air cooler |
| 8 | Charging pressure sensor |
| 9 | Throttle valve |
| 10 | Charge air pipe |
| 11 | Hot film air mass meter |
| 12 | Exhaust-gas turbocharger |
| 13 | Charge-air temperature sensor |
| 14 | Purified air pipe |