2009 Mercedes-Benz CLS550
The 2009 Mercedes-Benz CLS550 is a luxurious and stylish four-door coupe, known for its sleek design and powerful performance. The CLS550 came equipped with a 5.5-liter naturally aspirated V8 engine producing 382 horsepower and 391 lb-ft of torque. It was paired exclusively with a 7-speed automatic transmission (7G-Tronic). While praised for its smooth ride, elegant interior, and distinctive appearance, common complaints revolve around maintenance costs, electrical glitches, and some specific mechanical issues. Owners generally appreciate the car’s comfort and performance but dislike the potential for expensive repairs.
Engine
5.5L M273 V8
- Camshaft Adjuster Solenoid (Cam Magnet) Leak
- Description/Symptoms: Oil leaks from the camshaft adjuster solenoids (also known as cam magnets) can drip onto other engine components, causing a burning smell or potentially damaging other parts. Oil may also enter the engine wiring harness.
- Solution: Replace the leaking camshaft adjuster solenoid(s) and clean any affected wiring.
- Estimated Cost to Fix: $200 - $500+ (depending on how many solenoids need to be replaced and the extent of wiring harness damage)
- Recalls: None Found
- Valve Cover Gasket Leaks
- Description/Symptoms: Oil leaks from the valve cover gaskets are common as the gaskets age and harden. This can lead to a burning oil smell and visible oil leaks on the engine.
- Solution: Replace the valve cover gaskets.
- Estimated Cost to Fix: $400 - $800+
- Engine Mount Failure
- Description/Symptoms: Excessive engine vibration, especially at idle, along with clunking noises when accelerating or decelerating.
- Solution: Replace the engine mounts.
- Estimated Cost to Fix: $600 - $1200+ (due to the labor involved)
- Recalls: None Found
Transmission
7G-Tronic (722.9)
- Conductor Plate Failure
- Description/Symptoms: Erratic shifting, getting stuck in gear, transmission slipping, or complete loss of gear engagement. The check engine light may illuminate. Diagnostic codes related to valve body or speed sensor faults are common.
- Solution: Replace the conductor plate within the transmission. This often involves replacing the transmission fluid and filter as well.
- Estimated Cost to Fix: $800 - $1500+
- Recalls: None Found
- Torque Converter Failure
- Description/Symptoms: Shuddering or vibrations at low speeds, especially during acceleration. Possible stalling or difficulty shifting.
- Solution: Replace the torque converter. This may also require flushing the transmission fluid and inspecting the transmission for damage.
- Estimated Cost to Fix: $1500 - $3000+ (as it often involves removing the transmission)
- Recalls: None Found
Suspension
- Airmatic Suspension Failure
- Description/Symptoms: The car may sag on one or more corners, the ride may become harsh or bouncy, and the Airmatic warning light may illuminate. The air compressor may run constantly or fail to operate. Leaks in the air struts or air lines are common.
- Solution: Diagnose and replace the faulty component(s). This could include air struts, air compressor, valve block, or air lines.
- Estimated Cost to Fix: $800 - $2000+ per strut, $500 - $1000+ for the compressor, $300 - $600+ for the valve block.
- Recalls: None Found
Electrical
- Battery Drain Issues
- Description/Symptoms: The battery drains quickly, especially if the car is left unused for a few days. This can be caused by a faulty component not shutting down properly, such as the seat control module, instrument cluster, or amplifier.
- Solution: Diagnose and repair the source of the parasitic drain. This may involve testing individual circuits and components.
- Estimated Cost to Fix: $200 - $1000+ (depending on the complexity of the issue)
- Recalls: None Found
- SAM (Signal Acquisition Module) Failure
- Description/Symptoms: Multiple electrical issues may arise, such as malfunctioning lights, wipers, or other electronic accessories. Diagnostic codes related to the SAM unit are often present.
- Solution: Replace the faulty SAM unit and reprogram it.
- Estimated Cost to Fix: $800 - $1500+ (including parts and programming)
- Recalls: None Found
Exterior
- Headlight Condensation
- Description/Symptoms: Moisture buildup inside the headlight lenses, reducing visibility.
- Solution: Remove the headlights, dry them out, and reseal them. In severe cases, headlight replacement is needed.
- Estimated Cost to Fix: $200 - $500+ per headlight (resealing), $800 - $2000+ per headlight (replacement)
- Recalls: None Found
Interior
- Sunroof Issues
- Description/Symptoms: Sunroof may be jerky or slow to open/close. May make loud noises during operation or fail to open/close completely.
- Solution: Clean and lubricate the sunroof tracks and mechanism. If the motor or other components are faulty, they may need to be replaced.
- Estimated Cost to Fix: $100 - $300+ (lubrication and cleaning), $500 - $1500+ (motor or component replacement)
- Recalls: None Found
- Command System Malfunctions
- Description/Symptoms: The COMAND system screen may freeze, become unresponsive, or display error messages. Navigation, audio, or other functions may be affected.
- Solution: In some cases, a software update can resolve the issue. More severe cases may require replacing the COMAND unit.
- Estimated Cost to Fix: $100-300 (software update), $1000 - $3000+ (replacement)
- Recalls: None Found
Summary
The 2009 Mercedes-Benz CLS550, while a stylish and powerful vehicle, is prone to certain issues that owners should be aware of. Engine oil leaks and transmission conductor plate failures are fairly common and can be moderately expensive to repair. The Airmatic suspension, though providing a smooth ride, is a frequent source of trouble and can result in significant repair costs. Electrical glitches, such as battery drain issues and SAM module failures, can also occur. Overall, while the CLS550 offers a luxurious driving experience, potential owners should factor in the possibility of relatively high maintenance and repair expenses.