2021 Mercedes-Benz CLS53 AMG

The 2021 Mercedes-Benz CLS53 AMG is a performance-oriented four-door coupe that blends sleek styling with impressive power. It features a 3.0-liter inline-6 turbocharged engine with EQ Boost, producing 429 horsepower and 384 lb-ft of torque. The engine is paired with an AMG SPEEDSHIFT TCT 9-speed automatic transmission. While praised for its comfortable ride, elegant interior, and potent powertrain, some owners have reported experiencing specific issues. Other CLS models have different engines and transmissions, but the CLS53 AMG is unique in its powertrain configuration. Some common dislikes include the limited rear headroom due to the sloping roofline and the complexity of the infotainment system.

Engine

3.0L Inline-6 Turbocharged with EQ Boost

• Rough Idle/Hesitation
  • Description/Symptoms: Some owners have reported experiencing a rough idle or hesitation upon acceleration, particularly when the engine is cold. This can sometimes be attributed to issues with the direct injection system or the EQ Boost system.
  • Solution: Diagnosis by a qualified technician to pinpoint the cause (e.g., faulty injector, EQ Boost component). Replacement of the faulty part.
  • Estimated Cost to Fix: $500 - $2000+ depending on the component needing replacement.
  • Recalls: None Found
• EQ Boost System Malfunction
  • Description/Symptoms: Failure of the EQ Boost system, resulting in a loss of power, error messages on the dashboard, and potentially disabling the start/stop function.
  • Solution: Diagnosis to determine the faulty component within the EQ Boost system (e.g., integrated starter generator (ISG), battery). Replacement of the malfunctioning part.
  • Estimated Cost to Fix: $1000 - $4000+ depending on the component.
  • Recalls: None Found

Transmission

AMG SPEEDSHIFT TCT 9-speed Automatic

• Harsh Shifting/Jerking
  • Description/Symptoms: Some owners have reported experiencing harsh or jerky shifting, particularly during downshifts or at lower speeds. This can sometimes be caused by software issues or valve body issues.
  • Solution: Software update for the transmission control module (TCM). If the problem persists, inspection and potential replacement of the valve body.
  • Estimated Cost to Fix: $200 - $500 for software update; $1500 - $3000+ for valve body replacement.
  • Recalls: None Found
• Delayed Engagement
  • Description/Symptoms: Delay between shifting into drive or reverse and the vehicle actually moving.
  • Solution: Diagnosis to determine the cause, which could be low transmission fluid, valve body issues, or internal transmission damage. Fluid flush and refill, valve body repair or replacement, or transmission replacement may be necessary.
  • Estimated Cost to Fix: $300 - $500 for fluid flush; $1500 - $3000+ for valve body replacement; $5000 - $8000+ for transmission replacement.
  • Recalls: None Found

Suspension

• Air Suspension Issues (if equipped)
  • Description/Symptoms: Air suspension can fail, causing the car to sag on one side or multiple corners, ride height errors, or a bumpy ride. This often stems from leaks in the air struts or issues with the air compressor.
  • Solution: Diagnosis of the leak or compressor malfunction. Replacement of the air strut(s) or air compressor.
  • Estimated Cost to Fix: $1500 - $3000+ per strut; $1000 - $2500+ for compressor replacement.
  • Recalls: None Found

Electrical

• Infotainment System Freezing/Crashing
  • Description/Symptoms: The MBUX infotainment system can sometimes freeze, crash, or experience glitches, requiring a restart.
  • Solution: Software update for the infotainment system. If the problem persists, the head unit might need to be replaced.
  • Estimated Cost to Fix: $0 for software update (if available); $1000 - $3000+ for head unit replacement.
  • Recalls: None Found
• Sensor Malfunctions
  • Description/Symptoms: Malfunction of various sensors, such as parking sensors, blind spot monitoring sensors, or lane keeping assist sensors. This can result in error messages and/or non-functional safety systems.
  • Solution: Diagnosis to identify the faulty sensor. Replacement of the sensor.
  • Estimated Cost to Fix: $300 - $1000+ per sensor, depending on the type and location.
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Dashboard Delamination
  • Description/Symptoms: The dashboard material, especially on vehicles exposed to high heat, may start to delaminate or separate from the underlying structure.
  • Solution: Replacement of the entire dashboard, or repair by a specialized upholstery shop.
  • Estimated Cost to Fix: $2000 - $5000+ for dashboard replacement; repair costs vary.
  • Recalls: None Found
• Trim Pieces Loosening
  • Description/Symptoms: Certain interior trim pieces, especially around the door panels or center console, may become loose or detached.
  • Solution: Reattaching the trim piece or replacing broken clips or fasteners.
  • Estimated Cost to Fix: $100 - $500+ depending on the complexity of the repair.
  • Recalls: None Found

Summary

The 2021 Mercedes-Benz CLS53 AMG, while offering a luxurious and performance-oriented driving experience, has some known issues. The most concerning are related to the engine’s EQ Boost system and the transmission’s shifting behavior, which can lead to significant repair costs. Electrical issues with the infotainment system and sensor malfunctions can also be frustrating. While not all vehicles will experience these problems, prospective buyers should be aware of these potential issues and have the vehicle thoroughly inspected before purchasing.