The Mercedes-Benz ML320, particularly models from the late 2000s, represents a compelling option in the used SUV market. Having owned a 2008 ML320 CDI for a significant period, I can offer some firsthand insights into its ownership experience, focusing on aspects relevant to potential buyers and current owners alike. Notably, the 2008 models, similar to the 2007 versions, avoid the complexities of AdBlue systems, which were introduced in later ML320 iterations starting in 2009.
My purchase experience began at a local Mercedes-Benz dealership, ensuring a degree of initial confidence in the vehicle’s history. A thorough Carfax report and review of the prior owner’s Vehicle Master Inquiry (VMI) confirmed its local origins and meticulous dealership maintenance every 10,000 miles. This diligent servicing history during the warranty period pointed towards a vehicle that had been well cared for. With 106,000 miles on the odometer at the time of purchase, now exceeding 113,000 miles, the ML320 has proven to be a robust vehicle.
It’s suspected that the previous owner traded the vehicle due to a clogged catalytic converter, a repair that can be costly at dealerships, potentially around $3,000. Fortunately, the dealership addressed this issue prior to resale. For anyone considering an ML320 with similar mileage, verifying the catalytic converter’s replacement status is a prudent step.
The Advantages of the Mercedes ML320 CDI
This SUV earns its nickname “the beast” for good reason. Its robust performance is immediately apparent, providing a sense of effortless power in various driving conditions. As a highway cruiser, the ML320 CDI excels, achieving fuel economy in the mid-20s MPG range with diesel. While gasoline-powered ML320 models require premium unleaded fuel, their mileage remains respectable in the mid to high teens, considering the vehicle’s size and capability.
The interior of the ML320 is well-constructed, although some cost-saving measures are noticeable, reflecting industry-wide trends. A significant advantage of the pre-2009 diesel models is the absence of AdBlue, which translates to having a spare tire, albeit a compact one. Passenger space is generous, particularly in the second row, accommodating adults comfortably even with taller front occupants. At 6’3″, I find ample headroom and legroom without needing to push the driver’s seat fully back.
Addressing the ML320’s Drawbacks
While the audio system delivers impressive sound quality, including near-competition level bass, its Bluetooth and iPod integration are undeniably dated by today’s standards. Functionality is present, but it lacks the seamlessness of modern systems. Notably, A2DP Bluetooth audio streaming, a now-common feature, was not yet prevalent when these vehicles were designed in the mid-2000s. The navigation system, while functional, also exhibits a degree of clunkiness compared to contemporary units. Negotiating for an updated navigation DVD with the dealer is advisable, as these can be a significant expense.
The power tailgate can be temperamental, sometimes operating erratically. This may indicate a weakening hydraulic system, as assisting its opening often allows it to complete the cycle automatically. The system’s complexity, involving a hydraulic pump and cylinder, suggests potential future maintenance needs.
Tire costs are another consideration. The factory-specified 19-inch tires are expensive to replace, and Tire Pressure Monitoring System (TPMS) sensor replacements are often necessary concurrently. My own tire replacement with Continental tires cost approximately $995, with an additional $260 for TPMS sensors purchased online and installed by the tire technician.
Maintenance Considerations for the ML320
Dealership oil change services can be costly. DIY oil changes are feasible, especially with a topsider oil extractor. However, strict adherence to the recommended “Mobil 1 ESP Formula M 5W40” is crucial, requiring 9 quarts per change at approximately $12 per quart. Oil changes are recommended every 10,000 miles, and fuel filter replacements every 20,000 miles.
Regarding transmission fluid, the official manual suggests a single change at 40,000 miles, followed by a “lifetime” fill. However, experience with Mercedes-Benz 722.6 transmissions (and later variants like the 722.9 in the ML320) suggests more frequent changes are prudent. Fluid changes every 50,000 miles after the initial 40,000-mile service are recommended. This transmission requires a specific Mercedes-Benz fluid, also in the premium price range, and the fluid change procedure is complex, lacking a dipstick for level checking.
The engine and vehicle systems exhibit considerable complexity compared to older diesel engines. The OM642 engine in the ML320 CDI is a technologically advanced unit, requiring a different approach to maintenance and diagnostics compared to simpler, older diesels. Fuel cleanliness is paramount for CDI engines, as water or contaminants can severely damage the injectors. Therefore, choosing reputable fuel stations is important. The fuel filter does incorporate a water separator for added protection.
Conclusion: Is a Used Mercedes ML320 a Good Buy?
Despite these potential drawbacks and maintenance considerations, a well-maintained Mercedes Ml320 CDI, particularly a 2007 or 2008 model, remains a highly recommendable used SUV. Prioritizing a vehicle with comprehensive service records and evidence of diligent maintenance is key to a positive ownership experience.
