2018 BMW 550i xDrive

The 2018 BMW 550i xDrive is a luxurious and powerful sedan that sits near the top of the 5 Series range. It came standard with a 4.4L TwinPower Turbo V8 engine producing 456 horsepower and 480 lb-ft of torque. Other engine options available for the 2018 5 Series included a 2.0L Turbo 4-cylinder and a 3.0L Turbo inline-6. All engine options in the 2018 5 Series were paired with an 8-speed automatic transmission. Owners generally praise the 550i xDrive for its strong acceleration, comfortable ride, and well-appointed interior. Common complaints include high maintenance costs, complex electronics, and occasional reliability issues.

Engine

4.4L TwinPower Turbo V8 (N63TU2)

• Oil Leaks
  • Description/Symptoms: Oil leaks can develop from various areas of the engine, including valve cover gaskets, oil filter housing gasket, and the turbocharger oil lines. Symptoms include visible oil leaks, burning oil smell, and low oil level.
  • Solution: Replace the leaking gaskets or seals.
  • Estimated Cost to Fix: $200 - $1500+ depending on the source of the leak.
• Coolant Leaks
  • Description/Symptoms: Coolant leaks can occur from the coolant expansion tank, hoses, or water pump. Symptoms include low coolant level, overheating, and visible coolant leaks.
  • Solution: Replace the leaking components.
  • Estimated Cost to Fix: $150 - $800+ depending on the source of the leak.
• Turbocharger Issues
  • Description/Symptoms: The turbos in the 4.4L V8 are complex and prone to issues such as oil leaks, boost leaks, or complete failure. Symptoms include reduced power, whistling noises from the engine bay, and check engine light.
  • Solution: Replace or rebuild the turbochargers.
  • Estimated Cost to Fix: $2,500 - $6,000+

Transmission

8-Speed Automatic (ZF 8HP)

• Rough Shifting
  • Description/Symptoms: The ZF 8HP transmission can sometimes exhibit rough or jerky shifting, especially during cold starts or at low speeds.
  • Solution: A software update or transmission fluid change may improve the shifting. In some cases, valve body replacement may be necessary.
  • Estimated Cost to Fix: $100 (fluid change) - $2500+ (valve body)
• Mechatronic Failure
  • Description/Symptoms: Internal failure of the transmission mechatronic (valve body) can occur. Symptoms include erratic shifting, gear slipping, or complete loss of drive.
  • Solution: Replace the valve body.
  • Estimated Cost to Fix: $2,500+

Suspension

• Adaptive Damper Issues
  • Description/Symptoms: If equipped with the adaptive suspension (Dynamic Damper Control), the dampers can fail, leading to a harsh ride or uneven handling. Error messages may appear on the dashboard.
  • Solution: Replace the faulty dampers.
  • Estimated Cost to Fix: $500 - $1200+ per damper

Electrical

• Battery Drain
  • Description/Symptoms: Excessive battery drain can occur due to various factors, including faulty modules, aftermarket accessories, or a failing battery. Symptoms include difficulty starting the car or a dead battery.
  • Solution: Diagnose and repair the source of the battery drain.
  • Estimated Cost to Fix: $100 - $500+ depending on the cause
• iDrive Issues
  • Description/Symptoms: The iDrive system can experience software glitches, screen freezes, or complete failure.
  • Solution: Software updates or replacement of the iDrive module may be necessary.
  • Estimated Cost to Fix: $100 - $1500+

Exterior

• Adaptive Headlight Malfunction
  • Description/Symptoms: The adaptive headlights can sometimes malfunction, causing them to point in the wrong direction or display error messages.
  • Solution: Recalibration or replacement of the headlight units may be required.
  • Estimated Cost to Fix: $200 - $1500+

Interior

• Seat Comfort Issues
  • Description/Symptoms: Some owners have complained about the seat bolsters being too firm or the lumbar support being inadequate.
  • Solution: Adjust seat settings to find a more comfortable position. Aftermarket seat cushions or professional upholstery modifications can be considered.
  • Estimated Cost to Fix: $0 - $500+

Recalls:

• 18V-362: The engine control unit (ECU) software may allow the engine to stall under certain conditions, increasing the risk of a crash.
• 18V-755: The front seat frames may not have been properly welded, which could increase the risk of injury in a crash.

Summary

The 2018 BMW 550i xDrive offers a potent blend of performance and luxury but can be prone to certain issues, particularly with the engine, transmission, and electrical systems. While some problems are relatively minor and inexpensive to fix, others, such as turbocharger failures or mechatronic issues, can be costly. Potential buyers should be aware of these potential issues and factor in maintenance costs when considering this vehicle. Addressing known issues promptly and performing regular maintenance can help mitigate the risk of major repairs.