2003 BMW 745Li
The 2003 BMW 745Li, part of the E65/E66 generation, marked a significant departure in BMW design. It was available with a 4.4L N62 V8 engine producing 325 horsepower and 330 lb-ft of torque. A shorter wheelbase version, the 745i, was also available with the same engine. A larger 6.0L V12 engine was used in the 760i and 760Li versions. All models used a 6-speed automatic transmission. Owners generally appreciated the car’s luxurious features, comfortable ride, and advanced technology for its time, but often found the iDrive system confusing and reliability to be a concern. The complex electronics and relatively short lifespan of some components resulted in numerous maintenance issues.
Engine
4.4L N62 V8
- Valve Stem Seal Failure
- Description/Symptoms: Excessive oil consumption, blue smoke from the exhaust, especially after the car has been sitting.
- Solution: Replacing the valve stem seals.
- Estimated Cost to Fix: $3,000 - $5,000+
- Recalls: None Found
- Coolant Leaks
- Description/Symptoms: Coolant loss, overheating, visible coolant leaks around the engine. Common sources include the coolant transfer pipe (also known as a “valley pan leak”) located under the intake manifold, and the coolant expansion tank.
- Solution: Replacing the coolant transfer pipe or coolant expansion tank.
- Estimated Cost to Fix: Coolant Transfer Pipe - $1,500 - $3,000+, Coolant Expansion Tank - $300 - $600+
- Recalls: None Found
- Alternator Failure
- Description/Symptoms: Battery light on, dimming headlights, difficulty starting, or complete electrical failure.
- Solution: Replacing the alternator.
- Estimated Cost to Fix: $500 - $1,000+
- Recalls: None Found
Transmission
6-Speed Automatic (ZF 6HP26)
- Slipping or Harsh Shifting
- Description/Symptoms: Delayed gear changes, jerky shifts, or the transmission slipping out of gear.
- Solution: Often requires a complete transmission rebuild or replacement. Replacing the valve body can sometimes address the issue, but it is not always a permanent fix.
- Estimated Cost to Fix: Transmission Rebuild - $3,000 - $6,000+, Valve Body Replacement - $1,000 - $2,000+
- Recalls: None Found
- Mechatronic Sleeve Leak
- Description/Symptoms: Transmission fluid leak, often noticeable as a puddle under the car. Can also lead to transmission issues due to low fluid levels.
- Solution: Replacing the mechatronic sleeve and refilling the transmission fluid.
- Estimated Cost to Fix: $300 - $700+
- Recalls: None Found
Suspension
- Air Suspension Failure
- Description/Symptoms: The car sitting unevenly, a warning light on the dashboard, the air compressor running constantly, or the car not raising or lowering properly.
- Solution: Replacing the air struts, air compressor, or ride height sensors. Leaks in the air lines can also cause problems.
- Estimated Cost to Fix: Air Strut Replacement - $800 - $1,500+ per strut, Air Compressor Replacement - $500 - $1,000+
- Recalls: None Found
- Control Arm Bushing Failure
- Description/Symptoms: Clunking noises from the front suspension, especially when going over bumps. Poor handling and uneven tire wear can also occur.
- Solution: Replacing the control arm bushings or the entire control arm assembly.
- Estimated Cost to Fix: $300 - $800+ per control arm
- Recalls: None Found
Electrical
- iDrive System Malfunctions
- Description/Symptoms: The iDrive screen freezing, rebooting, or displaying error messages. Buttons and the iDrive controller may become unresponsive.
- Solution: This can be caused by a variety of issues, including software glitches, a failing iDrive controller, or problems with the Central Information Display (CID). Sometimes a software update can resolve the issue, but often requires replacing faulty components.
- Estimated Cost to Fix: Software Update - $100 - $300, iDrive Controller Replacement - $500 - $1,000+, CID Replacement - $800 - $1,500+
- Recalls: None Found
- Battery Drain
- Description/Symptoms: The battery draining quickly, especially if the car sits for a few days. Can be caused by a parasitic drain from a faulty module or component.
- Solution: Requires diagnosing the source of the drain and repairing or replacing the faulty component.
- Estimated Cost to Fix: $200 - $1,000+ (depending on the source of the drain)
- Recalls: None Found
- Sensor Failures (ABS, TPMS, etc.)
- Description/Symptoms: Warning lights on the dashboard, such as the ABS light, TPMS light, or other system malfunction indicators.
- Solution: Replacing the faulty sensor.
- Estimated Cost to Fix: $200 - $500+ per sensor
- Recalls: None Found
Exterior
- Door Lock Actuator Failure
- Description/Symptoms: Doors not locking or unlocking properly, either with the key fob or the interior door lock switch.
- Solution: Replacing the faulty door lock actuator.
- Estimated Cost to Fix: $300 - $700+ per door
- Recalls: None Found
Interior
- Headliner Sagging
- Description/Symptoms: The headliner fabric detaching from the roof and sagging.
- Solution: Replacing or re-gluing the headliner fabric.
- Estimated Cost to Fix: $400 - $1,000+
- Recalls: None Found
- Sunroof Issues
- Description/Symptoms: Sunroof failing to open or close properly, getting stuck, or making excessive noise.
- Solution: Repairing or replacing the sunroof motor, tracks, or other components.
- Estimated Cost to Fix: $300 - $1,000+
- Recalls: None Found
Summary
The 2003 BMW 745Li, while offering a luxurious and technologically advanced driving experience, is prone to several common issues that can be expensive to repair. Engine issues like valve stem seal failures and coolant leaks, transmission problems such as slipping and harsh shifting, and suspension issues like air suspension failure are frequently reported. Electrical problems, particularly related to the iDrive system and battery drain, are also common. The severity of these issues ranges from moderate inconvenience to major mechanical failures. The cost to address these issues can be significant, making thorough inspection and maintenance history crucial when considering purchasing this vehicle.