2009 Mercedes-Benz C350

The 2009 Mercedes-Benz C350 is a popular luxury sedan known for its elegant styling, comfortable ride, and spirited performance. The C350 comes equipped with a 3.5-liter V6 engine producing 268 horsepower and 258 lb-ft of torque. Other engine options for the 2009 C-Class included a 1.8L inline-4 supercharged engine in the C200 Kompressor (available in some markets), a 3.0L V6 engine in the C300, and a 6.2L V8 engine in the C63 AMG. All engines were paired with a 7-speed automatic transmission. Many owners appreciate the C350’s balance of luxury and sportiness, while some common dislikes include its relatively high maintenance costs and potential for electrical issues.

Engine

3.5L V6 (M272)

• Camshaft Adjuster Solenoid Failure
  • Description/Symptoms: Check engine light with codes related to camshaft position, rough idling, decreased engine performance.
  • Solution: Replace faulty camshaft adjuster solenoid(s).
  • Estimated Cost to Fix: $200 - $600+ (depending on location and if one or more solenoids need replaced)
  • Recalls: None Found
• Intake Manifold Runner Flap Failure
  • Description/Symptoms: Check engine light, decreased engine performance, rough idling, poor fuel economy. The plastic components of the intake manifold can fail.
  • Solution: Replace the intake manifold. Upgraded aftermarket manifolds with metal components are available.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found
• Oil Leaks (Valve Cover, Oil Filter Housing)
  • Description/Symptoms: Visible oil leaks on the engine, burning oil smell, low oil level.
  • Solution: Replace valve cover gaskets, oil filter housing gasket.
  • Estimated Cost to Fix: $200 - $800+
  • Recalls: None Found
• Timing Chain Tensioner Issues
  • Description/Symptoms: Rattling noise on start-up, check engine light. Can cause damage to the engine if not repaired.
  • Solution: Replace the timing chain tensioner.
  • Estimated Cost to Fix: $500 - $1200+
  • Recalls: None Found

Transmission

7G-Tronic (722.9)

• Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, transmission slipping, getting stuck in gear, limp mode.
  • Solution: Replace the conductor plate in the transmission. Requires coding to the vehicle.
  • Estimated Cost to Fix: $800 - $1800+
  • Recalls: None Found
• Torque Converter Issues
  • Description/Symptoms: Shuddering or vibration during shifting, particularly at lower speeds.
  • Solution: Replace the torque converter or rebuild the transmission.
  • Estimated Cost to Fix: $1500 - $4000+
  • Recalls: None Found

Suspension

• Front Control Arm Bushing Wear
  • Description/Symptoms: Clunking noise from the front suspension, especially over bumps, imprecise steering.
  • Solution: Replace front control arm bushings or the entire control arm.
  • Estimated Cost to Fix: $300 - $1000+ (depending on whether bushings or entire arms are replaced and location)
  • Recalls: None Found
• Rear Subframe Bushing Wear
  • Description/Symptoms: Rear-end instability, clunking noises from the rear, vague handling.
  • Solution: Replace rear subframe bushings.
  • Estimated Cost to Fix: $500 - $1200+
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: Key not recognized, car won’t start, steering wheel may not unlock.
  • Solution: Replace the EIS module and program it to the vehicle.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found
• SAM (Signal Acquisition Module) Issues
  • Description/Symptoms: Various electrical malfunctions, including lighting problems, power window issues, or other electrical component failures.
  • Solution: Diagnose and replace the faulty SAM unit. Coding may be required.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Battery frequently dies, especially when the car sits for a few days.
  • Solution: Diagnose and repair the source of the parasitic drain. This could be a faulty module or accessory.
  • Estimated Cost to Fix: $100 - $500+ (depending on the source of the drain)
  • Recalls: None Found

Exterior

• Door Lock Actuator Failure
  • Description/Symptoms: Door not locking or unlocking with the remote or interior switch.
  • Solution: Replace the faulty door lock actuator.
  • Estimated Cost to Fix: $200 - $500+ per door
  • Recalls: None Found
• Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly, getting stuck, making excessive noise.
  • Solution: Repair or replace sunroof components, such as the motor, tracks, or cables.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found

Interior

• Climate Control Issues
  • Description/Symptoms: Malfunctioning AC or heater, uneven temperature distribution, blower motor issues.
  • Solution: Diagnose and repair or replace faulty components, such as the blower motor, blend door actuator, or AC compressor.
  • Estimated Cost to Fix: $200 - $1200+ (depending on the component)
  • Recalls: None Found
• Command System Malfunctions
  • Description/Symptoms: Navigation system freezing or crashing, audio system problems, display issues.
  • Solution: Software update, component repair, or replacement of the COMAND unit.
  • Estimated Cost to Fix: $300 - $2000+
  • Recalls: None Found

Summary

The 2009 Mercedes-Benz C350, while a luxurious and enjoyable car to drive, has several common issues owners might encounter. Engine issues like camshaft adjuster solenoid failure and intake manifold problems can affect performance. Transmission issues with the 7G-Tronic can be costly to repair. Electrical gremlins are also a potential concern. Suspension issues, while less critical, can impact ride quality. Overall, while some repairs may be relatively inexpensive, others can be quite costly, making it important to carefully inspect a used C350 and factor in potential maintenance costs.