2010 Mercedes-Benz CLS550

The 2010 Mercedes-Benz CLS550 is a luxury four-door coupe, known for its sleek design and powerful performance. The CLS550 features a 5.5-liter V8 engine producing 382 horsepower and 391 lb-ft of torque, paired with a 7-speed automatic transmission. Some owners praise the vehicle’s comfort, style, and powerful engine, while others dislike its maintenance costs and complex electronics. Other engine options include the CLS63 AMG which has a 6.2L V8.

Engine

5.5L V8 (M273)

• Camshaft Adjuster Solenoid (Cam Magnet) Failure
  • Description/Symptoms: Check engine light, rough idling, decreased fuel economy, and potential misfires. The camshaft adjuster solenoid can fail, causing timing issues.
  • Solution: Replace the faulty camshaft adjuster solenoid.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found
• Oil Leaks (Valve Cover Gaskets, Oil Filter Housing)
  • Description/Symptoms: Visible oil leaks on the engine, burning oil smell, low oil level. Common leak points include valve cover gaskets and the oil filter housing.
  • Solution: Replace the leaking gaskets or the oil filter housing.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found

Engine

6.2L V8 (M156)

• Head Bolt Failure
  • Description/Symptoms: Coolant loss, overheating, white smoke from exhaust, potential engine damage. Certain years of the M156 engine had issues with the head bolts corroding and failing. This can cause coolant to leak into the cylinders.
  • Solution: Replace the head bolts, head gaskets, and possibly repair any engine damage caused by coolant intrusion.
  • Estimated Cost to Fix: $3000 - $6000+
  • Recalls: None Found
• Camshaft Adjuster Failure
  • Description/Symptoms: Ticking noise from the engine, rough idling, loss of power, check engine light.
  • Solution: Replace the camshaft adjusters.
  • Estimated Cost to Fix: $2000 - $4000+
  • Recalls: None Found

Transmission

7-Speed Automatic (722.9)

• Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, getting stuck in gear, transmission slipping, or complete loss of gear engagement. The conductor plate houses the transmission control unit (TCU) and speed sensors, and can fail due to heat and wear.
  • Solution: Replace the conductor plate and potentially the TCU.
  • Estimated Cost to Fix: $800 - $2000+
  • Recalls: None Found
• Valve Body Issues
  • Description/Symptoms: Hard shifts, delayed engagement, transmission slipping, or “limp mode.” The valve body controls fluid pressure and gear selection and can develop issues due to wear or debris.
  • Solution: Repair or replace the valve body.
  • Estimated Cost to Fix: $1000 - $3000+
  • Recalls: None Found

Suspension

• Airmatic Suspension Issues
  • Description/Symptoms: Car sitting low on one or more corners, hissing sound from air leaks, “Airmatic Visit Workshop” message on the dashboard. The Airmatic system can develop leaks in the air struts, compressor failure, or issues with the valve block.
  • Solution: Replace leaking air struts, repair or replace the air compressor, or replace the valve block.
  • Estimated Cost to Fix: $1000 - $3000+ per strut, $500 - $1500 for compressor, $300 - $800 for valve block.
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: Difficulty starting the car, key not recognized, or complete inability to start the vehicle. The EIS can fail, preventing the car from starting.
  • Solution: Replace the EIS and potentially reprogram it.
  • Estimated Cost to Fix: $800 - $2000+
  • Recalls: None Found
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Various electrical issues, such as malfunctioning lights, wipers, or other accessories. The SAM controls various electrical functions and can fail due to water intrusion or electrical overload.
  • Solution: Replace the faulty SAM unit and reprogram it.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly, making grinding noises, or leaking water. The sunroof mechanism can fail or become misaligned.
  • Solution: Repair or replace the sunroof mechanism.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found

Interior

• Navigation System Issues
  • Description/Symptoms: Navigation system freezing, not updating, or displaying incorrect information.
  • Solution: Update the navigation software or replace the navigation unit.
  • Estimated Cost to Fix: $200 - $1000+
  • Recalls: None Found

Summary

The 2010 Mercedes-Benz CLS550, while luxurious and powerful, can suffer from a range of issues. The most concerning are the potential engine and transmission problems, which can be quite costly to repair. The Airmatic suspension and electrical issues can also contribute to high maintenance costs. Potential buyers should be aware of these common problems and factor them into their purchasing decision.