2014 Mercedes-Benz GL550

The 2014 Mercedes-Benz GL550 is a full-size luxury SUV that offers a blend of performance, comfort, and practicality. The GL550 boasts a powerful 4.7-liter twin-turbo V8 engine producing 429 horsepower and 516 lb-ft of torque. Other engine options available in the GL-Class lineup include a 3.0-liter turbo V6 in the GL450 and a diesel 3.0-liter turbo V6 in the GL350 BlueTEC. All engines are paired with a 7-speed automatic transmission. Owners often praise the GL550 for its spacious interior, smooth ride, and powerful engine. Common complaints include high maintenance costs, electrical issues, and occasional air suspension problems.

Engine

4.7L Twin-Turbo V8 (M278)

• Oil Leaks
  • Description/Symptoms: Oil leaks can occur from various locations, including valve cover gaskets, oil filter housing, and rear main seal. Symptoms include visible oil leaks on the ground, burning oil smell, and low oil levels.
  • Solution: Replace the leaking gasket or seal. In some cases, resealing the component may be sufficient.
  • Estimated Cost to Fix: $200 - $1,500+ depending on the location and severity of the leak.
  • Recalls: None Found
• Turbocharger Failure
  • Description/Symptoms: Turbochargers can fail due to oil starvation, bearing wear, or internal damage. Symptoms include loss of power, excessive turbocharger noise (whining or screeching), and check engine light.
  • Solution: Replace the failed turbocharger. It’s recommended to replace both turbochargers simultaneously for balanced performance.
  • Estimated Cost to Fix: $2,500 - $5,000+ (per turbocharger, including labor)
  • Recalls: None Found
• Timing Chain Tensioner Failure
  • Description/Symptoms: The timing chain tensioner can fail, leading to a loose timing chain, which can cause engine misfires, rough running, and potential engine damage.
  • Solution: Replace the timing chain tensioner and inspect the timing chain for wear.
  • Estimated Cost to Fix: $1,500 - $3,000+
  • Recalls: None Found

Transmission

7G-TRONIC (722.9) 7-Speed Automatic

• Valve Body Issues
  • Description/Symptoms: The valve body can experience wear or damage, leading to erratic shifting, harsh shifts, slipping, or failure to shift.
  • Solution: Replace or rebuild the valve body. In some cases, a software update may temporarily alleviate the issue, but a valve body replacement is often necessary.
  • Estimated Cost to Fix: $800 - $2,500+
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: Torque converter failure can manifest as shuddering during acceleration, unusual noises, or complete transmission failure.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $1,200 - $3,000+
  • Recalls: None Found

Suspension

• Airmatic Air Suspension Failure
  • Description/Symptoms: The air suspension system can fail, leading to a sagging vehicle, uneven ride height, or a complete loss of suspension function. Common causes include leaky air struts, a failing air compressor, or a faulty air suspension control module.
  • Solution: Replace the faulty air strut(s), air compressor, or control module. It’s often recommended to replace air struts in pairs.
  • Estimated Cost to Fix: $1,000 - $3,000+ per air strut; $500 - $1,500+ for the air compressor; $300 - $800+ for the control module.
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: Excessive battery drain can lead to a dead battery overnight or within a few days. Potential causes include faulty modules, aftermarket accessories, or a parasitic draw.
  • Solution: Diagnose and repair the source of the battery drain. This may involve testing individual components to identify the culprit.
  • Estimated Cost to Fix: $100 - $1,000+, depending on the source of the drain.
  • Recalls: None Found
• Malfunctioning Sensors
  • Description/Symptoms: Various sensors, such as the mass airflow sensor (MAF), oxygen sensors, and crankshaft position sensor, can fail, leading to engine performance issues, check engine lights, and poor fuel economy.
  • Solution: Replace the faulty sensor.
  • Estimated Cost to Fix: $100 - $500+ per sensor.
  • Recalls: None Found
• COMAND System Issues
  • Description/Symptoms: The COMAND system (Mercedes-Benz’s infotainment system) can experience various issues, including freezing, unresponsive touchscreen, navigation problems, and Bluetooth connectivity issues.
  • Solution: Attempt a software update. If the issue persists, the COMAND unit may need to be repaired or replaced.
  • Estimated Cost to Fix: $200 - $2,000+
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroofs may get stuck open or closed, leak, or make excessive noise. This can be due to a broken motor, damaged tracks, or clogged drain tubes.
  • Solution: Repair or replace the sunroof motor, tracks, or drain tubes.
  • Estimated Cost to Fix: $200 - $1,500+
  • Recalls: None Found

Interior

• No Issues Found

Summary

The 2014 Mercedes-Benz GL550, while offering a luxurious experience, is prone to certain common issues. The engine and transmission can experience oil leaks, turbocharger issues, valve body problems, and torque converter failure, which can be quite costly to repair. The air suspension is another area of concern, with potential failures of air struts and compressors. Electrical problems, such as battery drain and sensor malfunctions, are also relatively common. While less frequent, sunroof problems can also occur. Overall, potential buyers should be aware of these issues and factor in potential repair costs when considering a 2014 GL550. Pre-purchase inspections are highly recommended.