2018 BMW 640i Gran Coupe

The 2018 BMW 640i Gran Coupe is a luxury four-door coupe known for its stylish design, comfortable ride, and sporty handling. The 640i comes standard with a 3.0-liter turbocharged inline-six engine producing 315 horsepower and 330 lb-ft of torque. All 640i models came standard with an 8-speed automatic transmission. While praised for its aesthetics and driving experience, some owners have reported certain recurring issues. Owners generally appreciate the car’s elegant design, spacious interior (for a coupe), and smooth, powerful engine. Downsides often mentioned include the relatively high cost of maintenance and repairs, the sometimes-complicated iDrive infotainment system, and limited rear headroom.

Engine

3.0L Turbocharged Inline-Six (B58)

• Oil Leaks
  • Description/Symptoms: Oil leaks, often originating from the valve cover gasket or the oil filter housing. This can manifest as visible oil drips under the car, a burning oil smell, or low oil level warnings.
  • Solution: Replacing the leaking gaskets or seals.
  • Estimated Cost to Fix: $300 - $800+ depending on the source of the leak.
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant leaks, often originating from the plastic coolant hoses and fittings. Common areas of leaks include the expansion tank and the hose connecting to the turbocharger. Symptoms may include a coolant smell, low coolant level warnings, or visible leaks.
  • Solution: Replace the faulty coolant hoses and fittings with updated, more durable parts.
  • Estimated Cost to Fix: $200 - $600+
  • Recalls: None Found

Transmission

8-Speed Automatic (ZF 8HP)

• Rough Shifting/Hesitation
  • Description/Symptoms: Some owners have reported instances of rough or delayed shifting, particularly during downshifts or when accelerating from a stop. Hesitation or “jerking” motions can also be experienced.
  • Solution: A transmission fluid flush and software update may resolve the issue. In more severe cases, valve body replacement or a full transmission rebuild may be necessary.
  • Estimated Cost to Fix: $300 for fluid flush and software update, $1,500 - $4,000+ for valve body replacement or rebuild.
  • Recalls: None Found

Suspension

• Adaptive Damper Malfunction
  • Description/Symptoms: The 640i Gran Coupe equipped with adaptive dampers (Dynamic Damper Control) may experience damper malfunctions. Symptoms include a harsh ride, uneven handling, or error messages on the iDrive screen related to the suspension.
  • Solution: Replacing the faulty damper(s). A diagnostic scan is necessary to identify the malfunctioning damper.
  • Estimated Cost to Fix: $800 - $1500+ per damper, including labor.
  • Recalls: None Found

Electrical

• iDrive System Issues
  • Description/Symptoms: The iDrive infotainment system can experience glitches, freezing, or complete failure. This can affect navigation, audio, climate control, and other vehicle functions.
  • Solution: Sometimes a software update can resolve the issue. In other cases, the iDrive control unit may need to be replaced.
  • Estimated Cost to Fix: $100 - $300 for a software update; $800 - $2000+ for control unit replacement.
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Excessive battery drain, leading to a dead battery after short periods of inactivity. This can be caused by a faulty module not properly going to sleep or excessive draw from a parasitic load.
  • Solution: Diagnosis to pinpoint the source of the drain, followed by replacement of the faulty component.
  • Estimated Cost to Fix: $100 - $200+ for diagnosis, component repair/replacement costs vary greatly.
  • Recalls: None Found

Exterior

• Adaptive Headlight Malfunction
  • Description/Symptoms: Adaptive headlights may fail to adjust properly or display error messages. The headlight may not swivel or level correctly.
  • Solution: Replacing the faulty headlight control module or the entire headlight assembly.
  • Estimated Cost to Fix: $500 - $2000+ depending on the specific issue and required parts.
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: The sunroof may exhibit issues such as failure to open or close, unusual noises, or leaks.
  • Solution: Repairing or replacing the sunroof motor, tracks, or seals.
  • Estimated Cost to Fix: $300 - $1200+ depending on the complexity of the repair.
  • Recalls: None Found

Summary

The 2018 BMW 640i Gran Coupe is a desirable vehicle, but prospective buyers should be aware of potential issues, particularly with the engine’s oil leaks, coolant leaks, the transmission’s shifting performance, and electrical gremlins related to the iDrive system and battery drain. While some issues can be resolved with relatively inexpensive fixes, others, such as transmission rebuilds or adaptive damper replacements, can be quite costly. The severity of these issues varies, but careful inspection and a pre-purchase inspection by a qualified mechanic are highly recommended.