2002 BMW 745i
The 2002 BMW 745i marked a significant departure from its predecessors with its controversial styling and advanced technology. The primary engine option was the 4.4L N62B44 V8 engine producing 325 horsepower and 330 lb-ft of torque, paired with a 6-speed automatic transmission. While some appreciated the car’s innovative features like iDrive and its luxurious interior, others criticized its complex electronics, polarizing design, and potential for expensive repairs. Common complaints included electrical gremlins, suspension issues, and engine oil leaks. A strong selling point for this car was its luxury features and powerful engine. A sore point was the high cost of maintenance and repairs, along with the complexity of the vehicle.
Engine
4.4L N62B44 V8
- Valve Stem Seal Failure
- Description/Symptoms: Excessive oil consumption, blue smoke upon startup, especially after the car has been sitting.
- Solution: Replacement of the valve stem seals.
- Estimated Cost to Fix: $3,000 - $6,000+
- Recalls: None Found
- Coolant Leaks (Valley Pan)
- Description/Symptoms: Coolant smell, visible coolant loss, overheating. Leaks often originate from the valley pan, which sits beneath the intake manifold.
- Solution: Replacement of the valley pan and associated gaskets.
- Estimated Cost to Fix: $1,500 - $3,000+
- Recalls: None Found
- Oil Leaks (Valve Cover Gaskets, Oil Pan Gasket, Timing Cover Gaskets)
- Description/Symptoms: Visible oil leaks on the engine, burning oil smell.
- Solution: Replacement of the affected gaskets.
- Estimated Cost to Fix: Valve Cover Gaskets: $500 - $1,500+, Oil Pan Gasket: $800 - $2,000+, Timing Cover Gaskets: $2,000+
- Recalls: None Found
- Alternator Bracket Oil Leak
- Description/Symptoms: Oil leaking from the front of the engine, near the alternator. This is often mistaken for a timing cover leak.
- Solution: Replacement of the alternator bracket gasket.
- Estimated Cost to Fix: $800-$1500+
- Recalls: None Found
Transmission
6-Speed Automatic (ZF 6HP26)
- Slipping/Harsh Shifting
- Description/Symptoms: Noticeable slipping between gears, delayed or harsh shifts, transmission fault codes. Can be more pronounced when cold.
- Solution: Fluid flush, Mechatronic unit replacement, valve body rebuild/replacement, or complete transmission replacement.
- Estimated Cost to Fix: Fluid flush: $300 - $500, Mechatronic Unit: $1,500 - $3,000+, Transmission Replacement: $5,000+
- Recalls: None Found
- Torque Converter Failure
- Description/Symptoms: Shuddering at low speeds, especially when accelerating. Can cause transmission fault codes.
- Solution: Replacement of the torque converter.
- Estimated Cost to Fix: $2,000 - $4,000+
- Recalls: None Found
Suspension
- Air Suspension Compressor Failure
- Description/Symptoms: “Self Level Susp. Inact.” warning on the iDrive screen, the car sitting low or unevenly, the compressor running constantly, or the car completely bottomed out.
- Solution: Replacement of the air suspension compressor and potentially the air struts if they are leaking.
- Estimated Cost to Fix: Compressor: $800 - $1,500+, Air Struts: $800 - $2,000+ per strut
- Recalls: None Found
- Air Strut Leaks
- Description/Symptoms: The car sitting low on one or more corners, “Self Level Susp. Inact.” warning, the compressor running excessively.
- Solution: Replacement of the leaking air struts.
- Estimated Cost to Fix: $800 - $2,000+ per strut
- Recalls: None Found
- Thrust Arm Bushings
- Description/Symptoms: Shaking or vibration in the steering wheel, especially when braking at highway speeds.
- Solution: Replacement of the thrust arm bushings or the entire thrust arm.
- Estimated Cost to Fix: $300 - $800 per side
- Recalls: None Found
Electrical
- iDrive Failures
- Description/Symptoms: The iDrive screen freezing, rebooting, or failing to function entirely.
- Solution: Software update, replacement of the iDrive controller, or replacement of the entire iDrive system.
- Estimated Cost to Fix: Controller: $500 - $1,500, iDrive system: $2,000+
- Recalls: None Found
- Battery Drain Issues
- Description/Symptoms: The battery draining overnight, difficulty starting the car. This is often due to a parasitic draw from a faulty module.
- Solution: Diagnosis of the parasitic draw and replacement of the faulty module.
- Estimated Cost to Fix: Varies greatly depending on the source of the drain. $200 - $1,000+
- Recalls: None Found
- Alternator Failure
- Description/Symptoms: Battery light on the dashboard, dimming headlights, difficulty starting the car, or the car stalling.
- Solution: Replacement of the alternator.
- Estimated Cost to Fix: $500 - $1,200+
- Recalls: None Found
- Comfort Access System Failures
- Description/Symptoms: The key fob not being recognized, difficulty locking/unlocking the doors, push-button start not working.
- Solution: Replacement of the comfort access antennas, control module, or key fob.
- Estimated Cost to Fix: $300 - $1,000+
- Recalls: None Found
Exterior
- Door Lock Actuator Failure
- Description/Symptoms: Door not locking or unlocking with the key fob or interior switch.
- Solution: Replacement of 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 backing and sagging down.
- Solution: Replacement or re-upholstering of the headliner.
- Estimated Cost to Fix: $500 - $1,500+
- Recalls: None Found
Summary
The 2002 BMW 745i, while offering luxury and performance, is plagued with a number of potentially costly issues. Engine problems such as valve stem seal failure and coolant leaks can lead to expensive repairs. The transmission is also prone to problems, with slipping and harsh shifting being common complaints. Electrical gremlins, particularly with the iDrive system and battery drain, can be frustrating to diagnose and fix. Suspension issues, especially with the air suspension, can also be costly. Overall, potential buyers should be aware of these potential issues and budget accordingly for repairs and maintenance. The severity of these issues ranges from moderate to severe, with costs ranging from a few hundred dollars to several thousand.