2018 BMW M4

The 2018 BMW M4 is a high-performance sports coupe and sedan that is praised for its sharp handling, powerful engine, and aggressive styling. The M4 is powered by a 3.0-liter twin-turbocharged inline-six engine, producing 425 horsepower and 406 lb-ft of torque in standard trim. The M4 Competition package bumps that up to 444 horsepower. Transmission options include a 6-speed manual and a 7-speed dual-clutch automatic transmission (DCT). Owners appreciate the M4’s exhilarating driving experience and the prestige associated with the BMW M badge. Common complaints revolve around the firm ride quality, especially on rough roads, and some reported reliability issues.

Engine

S55 3.0L Twin-Turbo Inline-Six

• Charge Air Cooler Leak
  • Description/Symptoms: Coolant loss, reduced engine performance, and potentially overheating. The charge air cooler, integrated into the intake manifold, can develop leaks.
  • Solution: Replacement of the charge air cooler/intake manifold assembly.
  • Estimated Cost to Fix: $2000 - $3000+
• Oil Leaks (Valve Cover/Oil Filter Housing)
  • Description/Symptoms: Visible oil leaks around the valve cover gasket or the oil filter housing. Burning oil smell. Low oil level.
  • Solution: Replacement of the valve cover gasket or the oil filter housing gasket.
  • Estimated Cost to Fix: $500 - $1500+

Transmission

7-Speed Dual-Clutch Transmission (DCT)

• DCT Shifting Issues/Hesitation
  • Description/Symptoms: Rough or jerky shifting, hesitation during gear changes, particularly at low speeds. Potential for “limp mode” activation.
  • Solution: Software update, clutch adaptation reset, or in severe cases, replacement of DCT clutches or the entire transmission unit.
  • Estimated Cost to Fix: $200 - $800+ (Software/Adaptation), $4000 - $10000+ (Clutch/Transmission Replacement)

Suspension

• Adaptive Suspension (Optional) Failure
  • Description/Symptoms: Uneven ride height, error messages related to the adaptive suspension system, noticeable degradation in ride quality.
  • Solution: Replacement of faulty shock absorbers or control modules.
  • Estimated Cost to Fix: $1000 - $3000+ per shock absorber

Electrical

• iDrive System Glitches
  • Description/Symptoms: Freezing, rebooting, or general unresponsiveness of the iDrive infotainment system.
  • Solution: Software update, replacement of the iDrive control unit (if hardware issue).
  • Estimated Cost to Fix: $100 - $500+ (Software), $1000 - $2000+ (Control Unit)
• Sensor Failures (Oxygen, Mass Airflow)
  • Description/Symptoms: Check engine light illumination, poor fuel economy, rough running engine.
  • Solution: Replacement of the faulty sensor.
  • Estimated Cost to Fix: $200 - $500+ per sensor

Exterior

• Carbon Fiber Roof Delamination (If Equipped)
  • Description/Symptoms: Clear coat on the carbon fiber roof begins to peel, bubble, or show signs of delamination.
  • Solution: Refinishing or replacement of the carbon fiber roof panel.
  • Estimated Cost to Fix: $500 - $2000+ (Refinishing), $5000 - $10000+ (Replacement)

Interior

• No Issues Found

Summary

The 2018 BMW M4, while offering exhilarating performance, is prone to certain issues. Engine and transmission problems can be costly, particularly DCT-related issues and charge air cooler leaks. Electrical gremlins and suspension problems can also add to the ownership expense. While not all M4s experience these issues, potential buyers should be aware of them and factor in the possibility of these repairs when considering a purchase. The severity ranges from sensor failures to complete transmission replacements, and costs can range from a few hundred dollars to over ten thousand dollars.