BMW 3-Series (E46) Repair Manual M3, 323i, 325i, 325xi, 328i, 330i, 330xi, Sedan, Coupe, Convertible, Sport Wagon 1999-2005

• BMW 323i, 323Ci: M52 TU, 2.5L engine



• BMW 328i, 328Ci: M52 TU, 2.8L engine



• BMW 325i, 325Ci, 325xi: M54/M56, 2.5L engine



• BMW 330i, 330Cis/330xi: M54, 3.0L engine



• BMW M3: S54, 3.2L Motorsport engine

RADIATOR AND EXPANSION TANK

The radiator is a crossflow design. An expansion tank provides for coolant expansion at higher temperatures and easy monitoring of the coolant level.

On cars with automatic transmission, ATF is circulated through an additional heat exchanger (ATF cooler).

Cooling fan (primary)

See illustration. There are two cooling fan configurations used on the cars covered by this manual, depending on transmission application.

On cars with automatic transmissions, the main fan is electric and mounted on the bumper side of the radiator. The fan is controlled by the DME control module via the output final stage. Additionally a belt-driven fan via a viscous Fluid coupling (clutch) is attached to the front of the coolant pump. The fan clutch controls the speed of the fan based on engine compartment temperature.

On cars with manual transmissions, a single multi-speed electric cooling fan is used. The fan is mounted on the engine side of the radiator and controlled by the DME control module via the output final stage.

On both configurations, the output final stage is mounted on the fan housing, next the fan motor. The fan is operated using a pulse width modulated (PWM) signal and is protected by a 50-amp fuse. Electric fan activation is based on the following inputs to the ECM:

• Radiator outlet temperature



• Catalyst temperature (calculated temperature)



• Vehicle speed



• Battery voltage



• A/C pressure (calculated pressure)

When the vehicle is first started, the ECM activates the electric fan briefly at 20% of its maximum speed, and then switches off. This is for diagnostic monitoring. The voltage generated by the fan when it slows down (acting as a generator) must match the stored 'rpm' values in the fan power output stage to confirm that the fan is operating correctly.

PARKING BRAKE

See illustration. The parking brake is a brake drum system integrated into the rear brake rotors.

The parking brake can be adjusted with the rear wheels installed but off the ground.

Adjust the parking brake under the following circumstances:

• Replacing parking brake shoes



• Replacing rear brake rotors



• Excessive stroke of parking brake handle required for actuation (more than 10 notches)



• Replacement of adjustment unit or parking brake cables



PARKING BRAKE SHOES | ADJUSTING


• See photo. Lift parking brake lever boot out of console. While holding cables stationary, loosen parking brake cable nuts (A) until cables are completely slack.



• Raise rear of car.



• Remove one lug bolt from each rear wheel. Turn road wheel until lug bolt hole lines up with parking brake adjuster (approximately 65 degrees to rear of wheel centerline).



• See illustration. Use flat-bladed screwdriver to turn adjuster.



• Left wheel: Turn adjuster in direction 1 to expand shoes.



• Right wheel: Turn adjuster in direction 2 to expand shoes.

• Important Safety Notice
• General Data and Maintenance
• Warnings and Cautions
• Vehicle Identification and VIN Decoder
• Engine
• Engine Removal and Installation
• Cylinder Head Removal and Installation
• Cylinder Head and Valvetrain
• Camshaft Timing Chain
• Lubrication System
• Ignition System
• Battery, Starter, Alternator
• Fuel Injection
• Radiator and Cooling System
• Transmission
• Clutch
• Manual Transmission
• Sequential Manual Gearbox (SMG)
• Automatic Transmission
• Gearshift Linkage
• Transfer Case
• Suspension, Steering and Brakes
• Body
• Body Equipment
• Seats
• Sunroof
• Convertible Top
• Electrical System
• Electrical Component Locations
• Instruments
• Heating and Air-conditioning
• Radio
• Equipment and Accessories
• Airbag System (SRS)
• Electrical Wiring Diagrams
• On-Board Diagnostics