2009 Mercedes-Benz ML500

The 2009 Mercedes-Benz ML500 is a luxury SUV offering a blend of comfort, performance, and technology. The ML500 comes with a 5.5-liter V8 engine producing 382 horsepower and 391 lb-ft of torque. Other engine options available include a 3.0-liter V6 diesel (ML320 BlueTEC/ML350 BlueTEC) and a 3.5-liter V6 gasoline engine (ML350). All engine options are paired with a 7-speed automatic transmission (7G-TRONIC). Owners often praise the ML500 for its smooth ride, powerful engine, and luxurious interior. Common dislikes include its high maintenance costs and occasional electronic glitches.

Engine

5.5L V8

• Oil Leaks from Valve Cover Gaskets
  • Description/Symptoms: Oil leaking onto the exhaust manifold, causing a burning smell. Visible oil around the valve covers.
  • Solution: Replacement of the valve cover gaskets.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found
• Camshaft Adjuster Solenoid (Variable Valve Timing) Issues
  • Description/Symptoms: Rough idling, poor performance, and potential check engine light illumination. Error codes related to camshaft position.
  • Solution: Replacement of the faulty camshaft adjuster solenoid.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found

3.5L V6

• Balance Shaft Sprocket Wear (M272 Engine)
  • Description/Symptoms: Rough engine running, engine noise (rattling), and a check engine light. This issue is more common in earlier M272 engines.
  • Solution: Replacement of the balance shaft and potentially the timing chain and related components.
  • Estimated Cost to Fix: $2,000 - $5,000+
  • Recalls: None Found

3.0L V6 Diesel (BlueTEC)

• Diesel Particulate Filter (DPF) Clogging
  • Description/Symptoms: Reduced engine performance, increased fuel consumption, and a DPF warning light.
  • Solution: Forced DPF regeneration (either through the vehicle’s system or by a mechanic), or DPF replacement.
  • Estimated Cost to Fix: $200 - $400 (regeneration), $1,500 - $3,000+ (replacement)
  • Recalls: None Found
• AdBlue (Diesel Exhaust Fluid) System Issues
  • Description/Symptoms: Check engine light, AdBlue warning light, and potential restrictions in engine performance. Problems can include faulty AdBlue injectors, level sensors, or pumps.
  • Solution: Diagnosis and repair or replacement of the faulty AdBlue system component.
  • Estimated Cost to Fix: $200 - $1,500+ depending on the component.
  • Recalls: None Found

Transmission

7G-TRONIC (722.9)

• Valve Body Issues
  • Description/Symptoms: Harsh shifting, delayed engagement, slipping, or failure to shift. Can trigger transmission fault codes. This is a known weakness of the 722.9 transmission.
  • Solution: Replacement or refurbishment of the valve body.
  • Estimated Cost to Fix: $800 - $2,000+
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration at low speeds, especially during acceleration. Transmission may not engage properly.
  • Solution: Replacement of the torque converter.
  • Estimated Cost to Fix: $1,000 - $2,500+
  • Recalls: None Found

Suspension

• Airmatic Suspension Compressor Failure (if equipped)
  • Description/Symptoms: Vehicle sagging on one or more corners, failure to maintain ride height, “Airmatic Visit Workshop” warning. Noises from the compressor.
  • Solution: Replacement of the air suspension compressor.
  • Estimated Cost to Fix: $500 - $1,500+
  • Recalls: None Found
• Airmatic Strut Leaks (if equipped)
  • Description/Symptoms: Vehicle sagging, especially overnight. Hissing sound from the strut.
  • Solution: Replacement of the leaking air strut.
  • Estimated Cost to Fix: $800 - $2,000+ per strut
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: Key not recognized, inability to start the vehicle, steering wheel lock malfunctions.
  • Solution: Replacement or repair of the EIS.
  • Estimated Cost to Fix: $500 - $1,500+
  • Recalls: None Found
• SAM (Signal Acquisition Module) Issues
  • Description/Symptoms: Various electrical malfunctions, such as lighting problems, window issues, or issues with other electronic components.
  • Solution: Diagnosis of the affected SAM and repair or replacement as needed.
  • Estimated Cost to Fix: $300 - $1,000+
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Dead battery after short periods of inactivity.
  • Solution: Diagnosis of parasitic drain and repair of the faulty component.
  • Estimated Cost to Fix: $100 - $500+ depending on the cause.
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroof motor failure, binding, or water leaks.
  • Solution: Repair or replacement of the sunroof motor or components. Sealing leaks.
  • Estimated Cost to Fix: $200 - $800+
  • Recalls: None Found

Interior

• Navigation System Failure
  • Description/Symptoms: Inability to access navigation functions, frozen screen, or system crashes.
  • Solution: Software update, repair, or replacement of the navigation unit.
  • Estimated Cost to Fix: $200 - $1,000+
  • Recalls: None Found

Summary

The 2009 Mercedes-Benz ML500, while a comfortable and capable SUV, can suffer from a variety of issues. Engine problems range from relatively minor oil leaks to more significant issues like balance shaft wear in earlier V6 models. Transmission problems related to the valve body are common. The air suspension, if equipped, is also a potential source of expensive repairs. Electrical gremlins, particularly with the EIS and SAM modules, can also occur. Overall, the severity of potential issues ranges from moderate to severe, with repair costs that can be substantial. Pre-purchase inspections and a thorough maintenance history review are highly recommended.