2018 BMW M550i xDrive

The 2018 BMW M550i xDrive is a high-performance sedan that bridges the gap between the standard 5 Series and the full-fledged M5. It comes equipped with a potent 4.4-liter TwinPower Turbo V8 engine producing 456 horsepower and 480 lb-ft of torque. The engine is mated to an 8-speed automatic transmission. People generally praise the car for its strong acceleration, comfortable ride, and luxurious interior. Common complaints often revolve around the high cost of maintenance, complex electronics, and the potential for expensive repairs.

Engine

4.4L TwinPower Turbo V8 (N63B44TU2)

• Oil Leaks
  • Description/Symptoms: Oil leaks can occur from various points in the engine, including valve cover gaskets, oil filter housing, and the oil pan gasket. Symptoms include visible oil drips under the car, a burning oil smell, and low oil levels.
  • Solution: Replace the leaking gaskets or seals. Clean the affected areas to ensure proper sealing.
  • Estimated Cost to Fix: $200 - $1,500+ depending on the location of the leak.
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant leaks often originate from the coolant transfer pipe (the “valley pan”) located beneath the intake manifold. This can lead to overheating, coolant loss, and potential engine damage. A sweet, antifreeze-like odor may be present.
  • Solution: Replacement of the coolant transfer pipe, intake manifold gaskets and other potentially brittle coolant lines.
  • Estimated Cost to Fix: $1,500 - $3,000+
  • Recalls: None Found
• Turbocharger Issues
  • Description/Symptoms: Some owners have reported issues with turbocharger failure or wastegate malfunctions. Symptoms include loss of power, whistling noises, and fault codes related to turbocharger boost.
  • Solution: Replacement of the faulty turbocharger(s) or repair of the wastegate mechanism.
  • Estimated Cost to Fix: $3,000 - $6,000+ per turbocharger.
  • Recalls: None Found

Transmission

8-Speed Automatic (ZF 8HP75)

• Rough Shifting/Hesitation
  • Description/Symptoms: Some owners experience rough or delayed shifting, particularly when cold or between certain gears. Hesitation during acceleration can also be a symptom.
  • Solution: Software update, transmission fluid change, or valve body replacement.
  • Estimated Cost to Fix: $300 - $2,000+ depending on the issue.
  • Recalls: None Found
• Mechatronic Unit Failure
  • Description/Symptoms: The Mechatronic unit controls the transmission’s shifting. Failure can result in erratic shifting, limp mode, or complete transmission failure.
  • Solution: Replacement of the Mechatronic unit.
  • Estimated Cost to Fix: $2,500 - $4,000+
  • Recalls: None Found

Suspension

• Air Suspension Issues (If Equipped)
  • Description/Symptoms: If the vehicle is equipped with optional air suspension, issues such as compressor failure, air leaks in the struts, or ride height sensor malfunctions may occur. Symptoms include the vehicle sitting unevenly, a noisy compressor, or suspension warning lights.
  • Solution: Replacement of the faulty compressor, struts, or ride height sensors.
  • Estimated Cost to Fix: $800 - $3,000+ per strut/compressor.
  • Recalls: None Found
• Adaptive Damper Malfunctions
  • Description/Symptoms: Failure of the electronic dampers (if equipped with Adaptive M Suspension) can lead to a harsh or bouncy ride, loss of handling precision, and fault codes.
  • Solution: Replacement of the faulty damper(s).
  • Estimated Cost to Fix: $500 - $1,500+ per damper.
  • Recalls: None Found

Electrical

• Battery Drain Issues
  • 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: Diagnosis and repair of the cause of the battery drain. Replacement of the battery if necessary.
  • Estimated Cost to Fix: $150 - $1,000+ depending on the issue.
  • Recalls: None Found
• iDrive System Malfunctions
  • Description/Symptoms: The iDrive infotainment system can experience glitches, freezes, or complete failure.
  • Solution: Software updates, replacement of the iDrive controller, or replacement of the head unit.
  • Estimated Cost to Fix: $200 - $2,000+ depending on the issue.
  • Recalls: None Found

Exterior

• Adaptive Headlight Malfunctions
  • Description/Symptoms: The adaptive headlights can experience issues such as failure to adjust properly, error messages, or complete failure.
  • Solution: Replacement of the headlight unit or repair of the headlight control module.
  • Estimated Cost to Fix: $800 - $2,500+ per headlight.
  • Recalls: None Found

Interior

• Seat Motor Failure
  • Description/Symptoms: The electric seat motors that control seat position can fail, preventing the seat from moving in one or more directions.
  • Solution: Replacement of the faulty seat motor or the entire seat assembly.
  • Estimated Cost to Fix: $300 - $1,500+ depending on the repair.
  • Recalls: None Found
• Sunroof Issues
  • Description/Symptoms: Sunroofs can experience issues such as motor failure, jamming, or leaks.
  • Solution: Repair or replacement of the sunroof motor, track, or seals.
  • Estimated Cost to Fix: $200 - $1,000+ depending on the issue.
  • Recalls: None Found

Summary

The 2018 BMW M550i xDrive, while offering impressive performance and luxury, can be prone to a range of issues, especially as it ages. The engine and transmission are common areas of concern, with oil leaks, coolant leaks, turbocharger issues, and transmission shifting problems being frequently reported. Electrical gremlins, suspension issues, and interior component failures also occur. The severity of these issues can range from minor inconveniences to major repairs, with costs varying accordingly. Potential buyers should be aware of these potential problems and factor them into their ownership considerations. Routine maintenance and a pre-purchase inspection by a qualified BMW technician are highly recommended.