2012 Mercedes-Benz E500
The 2012 Mercedes-Benz E500, also known as the E550 in some markets, is a luxury sedan known for its comfort, performance, and sophisticated features. The E-Class in this model year also included E350, and E63 AMG variants with different engines and performance characteristics. The E500/E550 is typically equipped with a 4.7L Twin-Turbo V8 engine producing around 402 hp and 443 lb-ft of torque, paired with a 7-speed automatic transmission (7G-Tronic). Owners often praise the E500/E550 for its smooth ride, powerful engine, and luxurious interior. Common criticisms include the complexity of the electronics and the higher maintenance costs associated with a luxury vehicle.
Engine
4.7L Twin-Turbo V8 (M278)
- Oil Leaks
- Description/Symptoms: Oil leaks are common, often originating from the valve cover gaskets, oil filter housing, or the turbocharger oil lines. Symptoms include visible oil drips under the car, a burning oil smell, and low oil levels.
- Solution: Replacing the affected gaskets or lines. Properly torquing bolts during replacement is crucial.
- Estimated Cost to Fix: $300 - $1,500+ (depending on the location and severity of the leak, and if turbochargers need removal)
- Recalls: None Found
- Timing Chain Tensioner Issues
- Description/Symptoms: Premature wear or failure of the timing chain tensioner can lead to rattling noises from the engine, especially during cold starts. In severe cases, it can cause timing chain slippage and significant engine damage.
- Solution: Replacing the timing chain tensioner and potentially the timing chain itself if wear is detected.
- Estimated Cost to Fix: $1,500 - $4,000+ (depending on the extent of damage and parts needed)
- Recalls: None Found
- Turbocharger Failure
- Description/Symptoms: Reduced engine power, whistling noises from the engine bay, and potentially check engine lights. Smoke from the exhaust may also be observed.
- Solution: Replacing the faulty turbocharger. It’s often recommended to replace both turbos at the same time to ensure balanced performance.
- Estimated Cost to Fix: $3,000 - $6,000+ (including parts and labor for both turbos)
- Recalls: None Found
Transmission
7G-Tronic (722.9)
- Torque Converter Issues
- Description/Symptoms: Shuddering or vibrations during acceleration, especially at lower speeds. Can also cause harsh shifting or slipping between gears.
- Solution: Replacing the torque converter.
- Estimated Cost to Fix: $1,500 - $3,000+
- Recalls: None Found
- Valve Body Problems
- Description/Symptoms: Erratic shifting, harsh gear changes, or failure to shift into certain gears. The transmission may also go into “limp mode.”
- Solution: Replacing or rebuilding the valve body. Sometimes, cleaning the valve body and replacing solenoids can resolve the issue.
- Estimated Cost to Fix: $800 - $2,500+
- Recalls: None Found
- Conductor Plate Failure
- Description/Symptoms: Erratic shifting behavior, the transmission may be stuck in gear. Check engine light.
- Solution: Replacing conductor plate.
- Estimated Cost to Fix: $800 - $1,500+
- Recalls: None Found
Suspension
- Air Suspension Issues (Airmatic)
- Description/Symptoms: The vehicle may sag on one or more corners, the air compressor may run constantly, or the “car rising” message may appear on the dash. Leaks in the air struts or lines are common.
- Solution: Replacing the faulty air struts, air compressor, or air lines. It’s often recommended to replace air struts in pairs.
- Estimated Cost to Fix: $800 - $2,000+ per strut (including labor), $500 - $1,000+ for the compressor.
- Recalls: None Found
- Control Arm Bushing Failure
- Description/Symptoms: Clunking noises from the suspension, especially when going over bumps. Can also cause vague steering and uneven tire wear.
- Solution: Replacing the worn control arm bushings or the entire control arm assembly.
- Estimated Cost to Fix: $300 - $1,000+ per control arm (including labor).
- Recalls: None Found
Electrical
- SAM (Signal Acquisition Module) Failure
- Description/Symptoms: Various electrical malfunctions, such as malfunctioning lights, wipers, or other electronic accessories. The SAM module controls many of the vehicle’s electrical functions.
- Solution: Replacing the faulty SAM module and reprogramming it to the vehicle.
- Estimated Cost to Fix: $800 - $1,800+
- Recalls: None Found
- Battery Drain Issues
- Description/Symptoms: The battery drains quickly, especially when the car is not driven for a few days. Can be caused by a parasitic drain from a faulty module or accessory.
- Solution: Identifying and fixing the source of the parasitic drain. This may involve replacing a faulty module or disconnecting an aftermarket accessory.
- Estimated Cost to Fix: $100 - $1,000+ (depending on the source of the drain)
- Recalls: None Found
Exterior
- Panoramic Sunroof Issues
- Description/Symptoms: The sunroof may not open or close properly, or it may make loud noises. The sunroof mechanism can be prone to failure.
- Solution: Repairing or replacing the sunroof mechanism.
- Estimated Cost to Fix: $500 - $2,000+
- Recalls: None Found
Interior
- COMAND System Malfunctions
- Description/Symptoms: The COMAND system (Mercedes’ infotainment system) may freeze, reboot unexpectedly, or display error messages.
- Solution: Updating the COMAND software. If that doesn’t work, the COMAND unit may need to be replaced.
- Estimated Cost to Fix: $100 - $2,000+ (depending on whether a software update is sufficient or the unit needs to be replaced)
- Recalls: None Found
Summary
The 2012 Mercedes-Benz E500/E550 offers a luxurious driving experience but is susceptible to certain common issues. Engine oil leaks and timing chain tensioner problems can be costly, as can air suspension failures. Electrical issues with the SAM module and COMAND system are also potential concerns. Transmission problems, especially with the 7G-Tronic transmission, can further add to the ownership costs. While some repairs are relatively minor, others can be quite expensive, so a pre-purchase inspection by a qualified mechanic is highly recommended.