2018 Mercedes-Benz E400

The 2018 Mercedes-Benz E400 is a popular luxury sedan known for its comfortable ride, elegant interior, and advanced technology. It features a 3.0-liter twin-turbo V6 engine that produces 329 horsepower and 354 lb-ft of torque. Other engine options for the 2018 E-Class include a 2.0-liter turbo inline-4 (E300) and a 3.0L turbo inline-6 (E450). A 9-speed automatic transmission is standard across the E400 range. Owners generally appreciate the car’s smooth power delivery, luxurious features, and driver assistance systems. Some common complaints include the complexity of the infotainment system and the cost of maintenance and repairs.

Engine

3.0L Twin-Turbo V6

• Oil Leaks
  • Description/Symptoms: Oil leaks from the valve cover gaskets and/or the oil filter housing. This can lead to oil consumption, a burning smell, and eventually, low oil pressure if not addressed.
  • Solution: Replace the valve cover gaskets and/or the oil filter housing gasket.
  • Estimated Cost to Fix: $400 - $1,200+ depending on the source of the leak.
  • Recalls: None Found
• Turbocharger Issues
  • Description/Symptoms: Whining noise from the engine, reduced power, and potential check engine light illumination. Can be caused by a failing turbocharger.
  • Solution: Diagnose the turbocharger for damage or failure. Replace the turbocharger if necessary.
  • Estimated Cost to Fix: $2,000 - $4,000+
  • Recalls: None Found

Transmission

9G-Tronic 9-Speed Automatic (725.0)

• Rough Shifting
  • Description/Symptoms: Hesitation, jerky shifts, and/or clunking noises during gear changes.
  • Solution: Perform a transmission fluid flush and filter replacement. If the problem persists, it may require valve body repair or replacement.
  • Estimated Cost to Fix: $300 for fluid and filter, $1,500 - $3,000+ for valve body work.
  • Recalls: None Found
• Torque Converter Shudder
  • Description/Symptoms: A noticeable vibration or shudder, particularly at lower speeds and during light acceleration.
  • Solution: Transmission fluid flush with updated fluid, potentially torque converter replacement.
  • Estimated Cost to Fix: $300+ for fluid flush, $1,500 - $3,500+ for torque converter replacement.
  • Recalls: None Found

Suspension

• Air Suspension Failure (if equipped)
  • Description/Symptoms: Vehicle sitting lower than normal, especially on one side. “Vehicle Level Too Low” warning message. Air compressor noise or failure.
  • Solution: Diagnose and replace the faulty air spring, air strut, or air compressor. Check for leaks in the air lines.
  • Estimated Cost to Fix: $800 - $2,000+ per air strut/spring, $500 - $1,500+ for air compressor.
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: Car is dead or won’t start after sitting for a short period. Frequent jump starts are required.
  • Solution: Diagnose the source of the parasitic drain. Common culprits include faulty modules, aftermarket accessories, and malfunctioning sensors.
  • Estimated Cost to Fix: $150 - $1,000+ depending on the source of the drain.
  • Recalls: None Found
• Infotainment System Issues (COMAND)
  • Description/Symptoms: System freezes, glitches, slow response times, Bluetooth connectivity problems, and navigation errors.
  • Solution: Software update, system reset, or replacement of the COMAND unit.
  • Estimated Cost to Fix: $0 (software update if available) - $2,000+ for COMAND unit replacement.
  • Recalls: None Found
• Sensor Failures
  • Description/Symptoms: Malfunction of various sensors around the vehicle that may include parking sensors, blind spot monitoring sensors, lane keep assist sensors, etc. that cause error messages to display on the instrument cluster.
  • Solution: Diagnose the source of the failing sensor and replace it.
  • Estimated Cost to Fix: $300 - $1,000+ depending on the sensor that has failed.
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof gets stuck, won’t open or close properly, or makes excessive noise.
  • Solution: Lubricate the sunroof tracks and mechanism. Repair or replace the sunroof motor or regulator if necessary.
  • Estimated Cost to Fix: $200 - $1,000+
  • Recalls: None Found

Summary

The 2018 Mercedes-Benz E400, while a luxurious and well-regarded vehicle, can experience a range of issues. Engine oil leaks and turbocharger problems can be costly, as can air suspension failures if equipped. Transmission issues such as rough shifting can also lead to expensive repairs. Electrical issues, particularly related to battery drain and the infotainment system, are also common. The severity of these issues ranges from minor inconveniences to major mechanical failures. The estimated cost to fix these problems varies greatly, from a few hundred dollars for minor repairs to several thousand dollars for major component replacements. While some repairs are relatively inexpensive, overall these issues can be costly to repair.