2021 Mercedes-Benz CLS450

The 2021 Mercedes-Benz CLS450 is a stylish four-door coupe known for its elegant design and comfortable ride. The CLS450 comes standard with a 3.0-liter inline-6 turbocharged engine that produces 362 horsepower and 369 lb-ft of torque, paired with a 9G-TRONIC 9-speed automatic transmission. Some owners appreciate its luxurious interior, smooth ride, and advanced technology features. However, some dislike the limited rear headroom due to the sloping roofline and the higher price point compared to some competitors. There are no other engine options for the CLS450 for this year.

Engine

3.0L Inline-6 Turbocharged (M256)

• Auxiliary Coolant Pump Failure
  • Description/Symptoms: Some owners report issues with the auxiliary coolant pump failing. Symptoms include the engine overheating, warning lights on the dashboard, and reduced engine performance.
  • Solution: Replacement of the auxiliary coolant pump.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found
• Faulty Fuel Injectors
  • Description/Symptoms: The fuel injectors are responsible for delivering fuel to the engine. When one or more fuel injectors fail, the engine may experience misfires, rough idling, poor acceleration, and reduced fuel efficiency.
  • Solution: Replacement of the faulty fuel injector(s).
  • Estimated Cost to Fix: $200 - $400+ per injector
  • Recalls: None Found
• Check Engine Light due to sensor issues
  • Description/Symptoms: Several sensor issues seem to occur and trigger the Check Engine Light. These include the mass airflow sensor, oxygen sensor, and crankshaft position sensor.
  • Solution: Replacing the faulty sensor
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found

Transmission

9G-TRONIC 9-Speed Automatic (725.0)

• Rough or Jerky Shifting
  • Description/Symptoms: Some owners have reported experiencing rough or jerky shifting, especially during low-speed acceleration or deceleration. This can be caused by several factors, including low transmission fluid, worn valve body components, or software issues.
  • Solution: Check and replace transmission fluid. Diagnose for valve body issues and replacement if necessary. Software updates to transmission control module.
  • Estimated Cost to Fix: $300-$2,000+ depending on the cause.
  • Recalls: None Found
• Delayed Engagement
  • Description/Symptoms: Some owners have reported a delay when shifting into drive or reverse, which can be accompanied by a noticeable clunking sound. This issue may be caused by low transmission fluid, a faulty solenoid, or internal damage to the transmission.
  • Solution: Check and replace transmission fluid. Diagnose for solenoid issues and replacement if necessary. Diagnose for any internal damage.
  • Estimated Cost to Fix: $300 - $3,000+ depending on the cause.
  • Recalls: None Found

Suspension

• Air Suspension Issues (if equipped)
  • Description/Symptoms: CLS models equipped with the optional air suspension may experience issues such as air leaks, compressor failure, or uneven ride height. These problems can result in a bumpy ride, warning lights on the dashboard, and difficulty adjusting the suspension settings.
  • Solution: Diagnose and repair or replace faulty air struts, air compressor, or air lines.
  • Estimated Cost to Fix: $800 - $2,000+ per component
  • Recalls: None Found

Electrical

• Infotainment System Freezing or Crashing
  • Description/Symptoms: Owners have reported issues with the MBUX infotainment system freezing, crashing, or becoming unresponsive. This can affect various functions, including navigation, audio, and climate control.
  • Solution: Software updates may resolve the issue. In some cases, replacement of the infotainment unit may be necessary.
  • Estimated Cost to Fix: $0 (software update) - $1,500+ (unit replacement)
  • Recalls: None Found
• Sensor Malfunctions
  • Description/Symptoms: Issues with various sensors, such as parking sensors, blind-spot monitoring sensors, or rain sensors, have been reported. These malfunctions can result in false alarms, inaccurate readings, or complete failure of the affected system.
  • Solution: Diagnose and replace faulty sensors.
  • Estimated Cost to Fix: $200 - $500+ per sensor
  • Recalls: None Found

Exterior

• Sunroof/Panoramic Roof Issues
  • Description/Symptoms: Some owners have reported problems with the sunroof or panoramic roof, such as difficulty opening or closing, excessive noise, or water leaks. These issues can be caused by faulty motors, damaged seals, or misalignment of the roof panels.
  • Solution: Repair or replace faulty sunroof/panoramic roof components.
  • Estimated Cost to Fix: $300 - $1,500+
  • Recalls: None Found

Interior

• Seat Motor Malfunctions
  • Description/Symptoms: The power-adjustable seats may experience issues such as motors failing, causing the seat to be stuck in one position, or intermittent operation.
  • Solution: Replacement of the faulty seat motor.
  • Estimated Cost to Fix: $300 - $800+
  • Recalls: None Found

Summary

The 2021 Mercedes-Benz CLS450 exhibits a range of potential issues, spanning from engine and transmission concerns to electrical glitches and interior malfunctions. While some problems, such as sensor malfunctions or infotainment issues, may be relatively minor and inexpensive to resolve, others, like transmission problems or air suspension failures, could be more costly and time-consuming to repair. It’s crucial for prospective buyers to be aware of these potential issues and thoroughly inspect the vehicle before making a purchase. Also, consider obtaining a pre-purchase inspection from a qualified mechanic.