2015 Mercedes-Benz E400

The 2015 Mercedes-Benz E400 is a mid-size luxury car that offers a blend of performance and comfort. The E400 is equipped with a 3.0L twin-turbo V6 engine that produces 329 horsepower and 354 lb-ft of torque. Other engine options for the E-Class in 2015 include a 2.1L turbodiesel I4 (E250 BlueTEC), a 3.5L V6 (E350), and a 5.5L Biturbo V8 (E63 AMG). All E400 models are equipped with a 7-speed automatic transmission (7G-Tronic Plus). Owners often praise the E400 for its smooth ride, powerful engine, and luxurious interior. Some common complaints include electronic glitches and the cost of maintenance.

Engine

3.0L Twin-Turbo V6 (M276)

• Oil Leaks from Timing Chain Covers
  • Description/Symptoms: Oil leaking from the front of the engine. Visible oil residue on the engine block near the timing chain covers.
  • Solution: Replacing the timing chain cover gaskets and resealing the covers.
  • Estimated Cost to Fix: $1200 - $2000+
  • Recalls: None Found
• Faulty Camshaft Adjusters
  • Description/Symptoms: Rattling noise on cold start. Check engine light may illuminate.
  • Solution: Replacing the camshaft adjusters.
  • Estimated Cost to Fix: $2500 - $4000+
  • Recalls: None Found

Transmission

7G-Tronic Plus (722.9)

• Rough Shifting/Hesitation
  • Description/Symptoms: Harsh or delayed shifts between gears. Transmission slipping or hesitating during acceleration.
  • Solution: Valve body replacement or transmission software update. In some cases, a full transmission rebuild or replacement is required.
  • Estimated Cost to Fix: $800 (software update) - $5000+ (transmission replacement)
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration at low speeds. Stalling. Transmission slipping.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $1500 - $3000+
  • Recalls: None Found

Suspension

• Air Suspension Leaks (Airmatic System)
  • Description/Symptoms: Vehicle sitting unevenly. Compressor running constantly. Rough ride. “Car Too Low” warning message.
  • Solution: Replacing the leaking air struts or air compressor.
  • Estimated Cost to Fix: $800 - $2000+ per strut, $600 - $1500+ for compressor.
  • Recalls: None Found

Electrical

• Battery Drain Issues
  • Description/Symptoms: Car battery draining overnight or after short periods of inactivity. Difficult to start.
  • Solution: Diagnosing and repairing parasitic drain. Could be caused by a faulty module (e.g., COMAND, seat control), alarm system malfunction, or wiring issues.
  • Estimated Cost to Fix: $100 - $500+ (diagnostic), $200 - $1000+ (repair depending on the cause)
  • Recalls: None Found
• COMAND System Malfunctions
  • Description/Symptoms: Freezing, crashing, or unresponsive COMAND screen. Navigation issues. Bluetooth connectivity problems.
  • Solution: Software update, COMAND unit reset, or replacement of the COMAND unit.
  • Estimated Cost to Fix: $100-$300 (software), $500-$2000+ (COMAND Unit Replacement)
  • Recalls: None Found

Exterior

• Panoramic Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly. Unusual noises during operation. Water leaks.
  • Solution: Lubricating the sunroof tracks, repairing the sunroof mechanism, or replacing the sunroof motor. Sealing leaks.
  • Estimated Cost to Fix: $100 - $500+ (lubrication/minor repairs), $800 - $2000+ (motor/mechanism replacement), $100 - $500+ (sealing)
  • Recalls: None Found

Interior

• Dashboard Cracking
  • Description/Symptoms: Cracks appearing on the dashboard, especially in hot climates.
  • Solution: Replacing the dashboard.
  • Estimated Cost to Fix: $1500 - $3000+
  • Recalls: None Found

Summary

The 2015 Mercedes-Benz E400 is a generally reliable car, but owners should be aware of potential issues with the engine (oil leaks, camshaft adjusters), transmission (rough shifting), suspension (air suspension leaks), and electrical systems (battery drain, COMAND malfunctions). While some issues are relatively minor and inexpensive to fix, others can be quite costly, particularly those involving the engine, transmission, and air suspension. Checking for these issues before purchasing a used E400 is highly recommended.