2003 Mercedes-Benz ML500

The 2003 Mercedes-Benz ML500 is a mid-size luxury SUV known for its comfort and off-road capabilities. The ML500 comes equipped with a 5.0L V8 engine producing 288 horsepower and 325 lb-ft of torque. Other engine options for the 2003 ML-Class include a 3.2L V6 in the ML320 and a 4.3L V8 in the ML430. A common point of appreciation for owners is the smooth ride and powerful engine, while common complaints revolve around the vehicle’s electrical issues and relatively high maintenance costs.

Engine

5.0L V8 (M113)

• Oil Leaks
  • Description/Symptoms: Oil leaks are common, particularly from the valve cover gaskets, oil filter housing gasket, and front crankshaft seal. Symptoms include visible oil leaks, a burning oil smell, and low oil levels.
  • Solution: Replace the leaking gaskets or seals.
  • Estimated Cost to Fix: $200 - $800+ depending on the location of the leak.
• Mass Air Flow (MAF) Sensor Failure
  • Description/Symptoms: Rough idling, poor acceleration, and a check engine light are common symptoms of a failing MAF sensor.
  • Solution: Replacement of the MAF sensor.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found
• Catalytic Converter Failure
  • Description/Symptoms: Reduced engine performance, rattling noises from the exhaust, and a check engine light are common symptoms.
  • Solution: Replacement of the faulty catalytic converter(s).
  • Estimated Cost to Fix: $800 - $2000+ per converter depending on the brand used.
  • Recalls: None Found

Transmission

All Transmissions (5-Speed Automatic)

• Transmission Slipping/Harsh Shifting
  • Description/Symptoms: Slipping between gears, delayed engagement, and harsh or erratic shifting are common issues. Can be caused by low fluid, worn clutches, or a faulty valve body.
  • Solution: Perform a transmission fluid flush and filter change. If the problem persists, further diagnosis and repair of the valve body or a transmission rebuild/replacement may be necessary.
  • Estimated Cost to Fix: $200 (fluid flush) to $3000+ (rebuild/replacement)
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibrations at low speeds, especially during acceleration, are indicative of torque converter issues.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found

Suspension

• Air Suspension Failure (if equipped)
  • Description/Symptoms: The vehicle may sag or sit unevenly, the air compressor may run constantly, or a warning light may illuminate on the dashboard. Leaks in the air springs or faulty compressor/sensors are common causes.
  • Solution: Replacing leaking air springs, the air compressor, or associated sensors.
  • Estimated Cost to Fix: $500 - $1500+ per air spring; $400 - $800+ for the compressor.
  • Recalls: None Found
• Ball Joint Failure
  • Description/Symptoms: Knocking or clunking noises from the front suspension, especially when going over bumps.
  • Solution: Ball joint replacement.
  • Estimated Cost to Fix: $200 - $500+ per ball joint.
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: The battery frequently dies, especially after the vehicle sits for a few days. Possible causes include a parasitic draw from a faulty module, aftermarket accessories, or a failing alternator.
  • Solution: Diagnosis and repair of the parasitic draw, or replacement of the alternator.
  • Estimated Cost to Fix: $100 - $1000+ depending on the cause of the draw. Alternator replacement $300-$600.
  • Recalls: None Found
• Window Regulator Failure
  • Description/Symptoms: Windows failing to go up or down, or making unusual noises.
  • Solution: Window regulator replacement.
  • Estimated Cost to Fix: $200 - $400 per window.
  • Recalls: None Found
• Instrument Cluster Issues
  • Description/Symptoms: Flickering screen, dead pixels, or complete failure of the instrument cluster.
  • Solution: Instrument cluster repair or replacement.
  • Estimated Cost to Fix: $200 - $800+ depending on the extent of the damage and whether it is repaired or replaced.
  • Recalls: None Found

Exterior

• Rust
  • Description/Symptoms: Rust can form on the lower body panels, wheel arches, and undercarriage.
  • Solution: Rust repair including sanding, body filler, and repainting.
  • Estimated Cost to Fix: $300+ per area depending on severity.
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof failing to open or close properly, getting stuck, or leaking.
  • Solution: Sunroof track repair or replacement, cleaning and lubricating the sunroof mechanism, or replacing the sunroof motor.
  • Estimated Cost to Fix: $200 - $800+ depending on the issue.
  • Recalls: None Found

Summary The 2003 Mercedes-Benz ML500, while a comfortable and capable SUV, is prone to certain issues due to its age and complexity. Engine oil leaks and transmission problems are common and can be costly to address. Electrical issues such as battery drain and window regulator failures are also frequently reported. Suspension issues, particularly with the air suspension, can add to the maintenance burden. The severity and cost of these issues range from minor repairs to major overhauls, making a thorough inspection essential before purchasing a used ML500.