2021 BMW 840i Gran Coupe

Here’s a breakdown of common issues and complaints for the 2021 BMW 840i Gran Coupe, formatted for your website.

The 2021 BMW 840i Gran Coupe is a luxurious and sporty four-door coupe offering a blend of performance and comfort. The most common engine is the 3.0-liter turbocharged inline-six, producing 335 horsepower and 368 lb-ft of torque. Other engine options include a 4.4-liter twin-turbocharged V8 in the M850i model. Both engines are paired with an 8-speed automatic transmission. Owners generally praise the 840i Gran Coupe for its elegant styling, smooth ride, and powerful engine, while some criticisms include the somewhat cramped rear seating and the complexity of the infotainment system.

Engine

3.0L Turbocharged Inline-Six (B58)

• Oil Filter Housing Gasket Leak
  • Description/Symptoms: Oil leak near the top of the engine. Burning oil smell. Low oil level warning.
  • Solution: Replace the oil filter housing gasket.
  • Estimated Cost to Fix: $300 - $600
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant leak near the engine, overheating, low coolant level warning. The source can be difficult to pinpoint, sometimes originating from hoses, the water pump, or the expansion tank.
  • Solution: Identify and replace the leaking component.
  • Estimated Cost to Fix: $200 - $1000+ depending on the location and part.
  • Recalls: None Found

4.4L Twin-Turbocharged V8 (N63/S63 - M850i)

• Oil Leaks (Multiple Sources)
  • Description/Symptoms: Oil leaks from various points, including valve cover gaskets, turbocharger oil lines, and the rear main seal. Burning oil smell, low oil level.
  • Solution: Replace the leaking gaskets or seals. This often requires significant labor.
  • Estimated Cost to Fix: $500 - $3000+ depending on the source and complexity.
  • Recalls: None Found
• Turbocharger Issues
  • Description/Symptoms: Whining noises from the turbochargers, loss of power, check engine light. Potential causes include bearing failure or wastegate issues.
  • Solution: Diagnose the turbocharger issue and replace or repair the affected components.
  • Estimated Cost to Fix: $2000 - $6000+ for turbocharger replacement.
  • Recalls: None Found

Transmission

8-Speed Automatic (ZF 8HP)

• Rough Shifting/Hesitation
  • Description/Symptoms: Jerky or delayed shifts, especially between lower gears. Hesitation when accelerating.
  • Solution: Perform a transmission fluid flush and filter replacement. If the problem persists, valve body issues may require repair or replacement.
  • Estimated Cost to Fix: $300 - $600 for fluid and filter; $1500 - $4000+ for valve body work.
  • Recalls: None Found
• Mechatronic Unit Failure
  • Description/Symptoms: Erratic shifting, transmission going into limp mode, difficulty selecting gears.
  • Solution: Replace or rebuild the mechatronic unit.
  • Estimated Cost to Fix: $2500 - $5000+
  • Recalls: None Found

Suspension

• Adaptive Damper Malfunctions
  • Description/Symptoms: Warning lights related to the adaptive suspension system. Uneven ride quality, clunking noises.
  • Solution: Diagnose the faulty damper(s) and replace them.
  • Estimated Cost to Fix: $800 - $2000+ per damper.
  • Recalls: None Found

Electrical

• Infotainment System Glitches
  • Description/Symptoms: Freezing, lagging, or unexpected reboots of the iDrive infotainment system.
  • Solution: Software update, or in more severe cases, replacement of the head unit.
  • Estimated Cost to Fix: $0 (software update) - $2000+ (head unit replacement)
  • Recalls: None Found
• Sensor Failures
  • Description/Symptoms: Faulty readings from various sensors (e.g., parking sensors, tire pressure sensors), triggering warning lights.
  • Solution: Diagnose and replace the faulty sensor.
  • Estimated Cost to Fix: $100 - $500+ per sensor.
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Dashboard Rattle
  • Description/Symptoms: Annoying rattling noise coming from within the dashboard, especially on rough roads.
  • Solution: Identify the source of the rattle and secure the loose components. This may require disassembly of parts of the dashboard.
  • Estimated Cost to Fix: $100 - $500+ depending on the complexity and time required to fix
  • Recalls: None Found
• Seat Motor Issues
  • Description/Symptoms: Power seats that move slowly, erratically, or not at all. May affect one or more seat functions (e.g., recline, lumbar support).
  • Solution: Diagnose and replace the faulty seat motor(s).
  • Estimated Cost to Fix: $300 - $800+ per motor.
  • Recalls: None Found

Summary

The 2021 BMW 840i Gran Coupe, while a desirable luxury vehicle, can experience certain issues, particularly related to oil leaks in both the inline-six and V8 engines, and potential problems with the 8-speed automatic transmission. Electrical glitches and suspension malfunctions also appear. The severity and cost of these issues can range from relatively minor (sensor replacement, software updates) to significant (turbocharger replacement, transmission rebuild). Prospective buyers should be aware of these potential issues and thoroughly inspect any used 840i Gran Coupe before purchase.