The 2008 Mercedes ML320 CDI, while a luxurious and capable SUV, is known to have certain common problems. This article discusses these issues based on firsthand experience with four OM642-engined vehicles, offering insights into potential problems and solutions for the ML320 CDI.
Common 2008 Mercedes ML320 CDI Problems
One common issue with the OM642 engine is the oil cooler seals. These seals can fail, leading to oil leaks. In one instance, the oil cooler seals were replaced at around 125,000 miles. While the intake manifold had some build-up, it wasn’t excessively caked.
Another issue encountered was the failure of temperature sensors on the Diesel Particulate Filter (DPF). Vague fault codes made it difficult to pinpoint the faulty sensor, leading to the replacement of both sensors as a preventative measure. This is a relatively straightforward job with access beneath the vehicle.
Other potential problems include the need for oil filter tower gasket replacement and motor mount replacements as the vehicle ages and accumulates mileage. Regular maintenance and addressing these issues promptly can help prevent more significant problems down the road.
Emissions System and DPF Maintenance
All emissions systems on the vehicles remained intact and functional. Regular monitoring of the DPF ash percentage using diagnostic tools like Xentry is crucial. Sufficient mixed driving allows for frequent DPF regeneration, preventing clogging. Short, infrequent trips can hinder the DPF’s ability to regenerate, potentially leading to problems. For owners who primarily drive short distances, the ML320 CDI might not be the ideal choice. DPF flushing is an option for cleaning the DPF canister, which is relatively accessible under the vehicle.
Transmission and Other Considerations
While not directly related to the engine, a transmission conductor plate (VGS) replacement was necessary in a 2008 E320 with the same OM642 engine. This component is dealer-specific for replacement. Additionally, CAN bus failures can occur, but these are not specific to the OM642 engine. Other maintenance items encountered included front suspension rebuilds and oil filter tower gasket replacements.
Importance of Regular Maintenance
Consistent maintenance is key to the longevity of these vehicles. Using the recommended 229.52 oil and adhering to scheduled maintenance intervals are crucial for preventing major issues. Proactive maintenance and addressing minor problems early on can help avoid costly repairs in the long run. Experience with these vehicles has shown that while problems can arise, they are manageable with proper care and attention.
Conclusion
The 2008 Mercedes ML320 CDI can be a reliable vehicle with proper maintenance. Addressing common issues like oil cooler seals, DPF sensor problems, and regular maintenance can significantly extend the life of the vehicle. While issues can occur, proactive ownership and addressing problems promptly can keep your ML320 CDI running smoothly.
