2008 Mercedes-Benz GL500

The 2008 Mercedes-Benz GL500, also known in some markets as the GL550, is a full-size luxury SUV offering a blend of comfort and capability. It was also available with a GL320 CDI V6 Diesel, GL450 V8, and GL550 V8 depending on the market. The GL500 is equipped with a 5.5-liter V8 engine that produces 382 horsepower and 391 lb-ft of torque. Owners generally appreciate the GL500’s spacious interior, luxurious features, and smooth ride, but some common complaints revolve around maintenance costs, electronic glitches, and the air suspension system.

Engine

5.5L V8

• Oil Leaks from Valve Cover Gaskets
  • Description/Symptoms: Oil leaks are observed around the valve covers, potentially leading to burning smells or low oil levels.
  • Solution: Replace the valve cover gaskets.
  • Estimated Cost to Fix: $400 - $800+
• Camshaft Adjuster Solenoid (Cam Magnet) Leaks
  • Description/Symptoms: Oil leaks from the camshaft adjuster solenoids (cam magnets), which can wick into the wiring harness. Symptoms include oil on the connectors and potential engine performance issues.
  • Solution: Replace the leaking cam magnets and clean the wiring harness.
  • Estimated Cost to Fix: $200 - $500+ per magnet

Transmission

7G-Tronic (722.9)

• Valve Body Issues
  • Description/Symptoms: Harsh shifting, delayed engagement, or transmission slipping. These are common symptoms of a malfunctioning valve body within the 7G-Tronic transmission.
  • Solution: Replace or rebuild the valve body.
  • Estimated Cost to Fix: $800 - $2,000+
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibrations at certain speeds, especially under light acceleration. Can also cause stalling.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $1,500 - $3,000+

Suspension

• Airmatic Air Suspension Compressor Failure
  • Description/Symptoms: The vehicle sits low, especially overnight, and the air suspension warning light illuminates. The compressor may run constantly or not at all.
  • Solution: Replace the air suspension compressor.
  • Estimated Cost to Fix: $800 - $1,500+
• Airmatic Air Strut Leaks
  • Description/Symptoms: Similar to compressor failure, the vehicle may sag on one or more corners. Hissing sounds may be heard from the leaking strut.
  • Solution: Replace the leaking air strut.
  • Estimated Cost to Fix: $800 - $2,000+ per strut (depending on location and if aftermarket)

Electrical

• Battery Drain Issues
  • Description/Symptoms: The battery drains overnight or within a few days, even with a new battery. This can be caused by a faulty module or a parasitic draw in the electrical system.
  • Solution: Diagnose and repair the source of the parasitic draw. This may involve replacing a faulty module (e.g., seat control module, door control module) or repairing wiring.
  • Estimated Cost to Fix: $200 - $1,000+ (depending on the source of the drain)
• COMAND System Malfunctions
  • Description/Symptoms: The COMAND (cockpit management and data) system, which controls navigation, audio, and other functions, may freeze, reboot, or display error messages.
  • Solution: Software update, replacement of the COMAND unit or individual components.
  • Estimated Cost to Fix: $300 - $2,000+

Exterior

• Rust on Lower Door Panels and Wheel Arches
  • Description/Symptoms: Surface rust appears on the lower edges of the doors and around the wheel arches, particularly in regions with road salt usage.
  • Solution: Repair and repaint the affected areas.
  • Estimated Cost to Fix: $500 - $2,000+ (depending on the extent of the rust)

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof malfunctions, including getting stuck, not opening or closing properly, or making excessive noise.
  • Solution: Lubricate the tracks, repair or replace the sunroof motor, or replace damaged components.
  • Estimated Cost to Fix: $200 - $1,000+
• Power Seat Problems
  • Description/Symptoms: Power seats stop working or move intermittently due to faulty motors or switches.
  • Solution: Replace the faulty seat motor or switch.
  • Estimated Cost to Fix: $200 - $800+ per seat

Recalls:

• 2008070003

Summary

The 2008 Mercedes-Benz GL500 offers luxury and space but comes with potential maintenance challenges. The most common issues revolve around the air suspension, engine oil leaks, transmission problems, and electrical gremlins. Repairs can be costly, especially those involving the air suspension or the transmission. Potential buyers should be aware of these common issues and factor them into their purchasing decision.