2021 BMW 840i

The 2021 BMW 840i is a luxury grand tourer known for its sleek design, comfortable ride, and powerful engine options. The 840i is equipped with a 3.0-liter turbocharged inline-6 engine producing 335 horsepower and 369 lb-ft of torque. Other engine options for the 2021 8 Series include a more powerful V8. All engines are paired with an 8-speed automatic transmission. Owners generally appreciate the car’s styling, performance, and luxurious interior. Common complaints tend to focus on the infotainment system’s complexity and the high cost of maintenance and repairs.

Engine

3.0L Turbocharged Inline-6 (B58)

• Oil Leaks
  • Description/Symptoms: Oil leaks can occur from the oil filter housing gasket or the valve cover gasket. Symptoms include visible oil leaks under the vehicle, a burning oil smell, and low oil levels.
  • Solution: Replacing the faulty gasket is the typical solution.
  • Estimated Cost to Fix: $300 - $800+
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant leaks can develop from the water pump or coolant hoses. Symptoms include low coolant levels, overheating, and visible coolant leaks.
  • Solution: Replacing the water pump and/or coolant hoses.
  • Estimated Cost to Fix: $500 - $1200+
  • Recalls: None Found

Transmission

8-Speed Automatic (ZF 8HP)

• Rough Shifting
  • Description/Symptoms: Some owners report experiencing rough or jerky shifting, particularly during low-speed acceleration or deceleration. This may be more noticeable in earlier production units or under specific driving conditions.
  • Solution: In some cases, a software update can address the issue. In others, a transmission fluid flush and filter replacement may improve shifting smoothness. If the problem persists, valve body replacement or complete transmission overhaul might be necessary.
  • Estimated Cost to Fix: $200 (software update) - $400 (fluid flush) - $2000+ (valve body/overhaul)
  • Recalls: None Found
• Hesitation
  • Description/Symptoms: The transmission hesitates or “slips” when accelerating, followed by a harsh engagement.
  • Solution: A software update or transmission fluid replacement. In severe cases, the transmission needs to be replaced.
  • Estimated Cost to Fix: $200 (software update) - $400 (fluid flush) - $5,000+ (transmission replacement)
  • Recalls: None Found

Suspension

• Adaptive Damper Malfunctions
  • Description/Symptoms: The adaptive dampers can fail, causing a noticeably harsher or bouncier ride. Error messages related to the suspension system may appear on the dashboard.
  • Solution: Replacing the faulty damper(s) is the usual fix.
  • Estimated Cost to Fix: $800 - $1500+ per damper
  • Recalls: None Found

Electrical

• Infotainment System Glitches
  • Description/Symptoms: The iDrive infotainment system can experience occasional glitches, such as freezing, slow response times, or unexpected reboots.
  • Solution: Often, a software update can resolve these issues. However, in some cases, a replacement of the infotainment control unit may be required.
  • Estimated Cost to Fix: $0 (software update) - $1000+ (control unit replacement)
  • Recalls: None Found
• Sensor Failures
  • Description/Symptoms: Various sensors, such as parking sensors, can malfunction, leading to inaccurate readings or error messages.
  • Solution: Replacing the faulty sensor.
  • Estimated Cost to Fix: $200 - $500+ per sensor
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Seat Motor Failure
  • Description/Symptoms: The power seat motors might fail.
  • Solution: Replacing the failed motor.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found

Summary

The 2021 BMW 840i presents a mix of common luxury car issues. While the engine is generally reliable, potential oil and coolant leaks should be monitored. The transmission can experience some shifting issues that may require software updates or more extensive repairs. Electrical glitches and sensor failures are also relatively common. Suspension issues, particularly with the adaptive dampers, can be costly to fix. While many issues are relatively minor, the high cost of parts and labor at BMW dealerships or qualified independent shops can make repairs expensive.