Mercedes-Benz has long been synonymous with luxury, performance, and engineering excellence. For those in the market for a reliable used vehicle, older Mercedes models, particularly their diesel variants, often stand out as exceptional choices. Renowned for their robust construction and longevity, these cars, when properly maintained, can offer years of dependable service. This guide delves into what makes certain older Mercedes diesels some of the best used cars available, focusing on key aspects to consider when making a purchase.
Why Choose an Older Mercedes Diesel?
The allure of older Mercedes diesels lies in their legendary durability and straightforward engineering. Unlike some modern vehicles with complex electronics and delicate components, these cars were built to last. The engines, especially the 5-cylinder diesel, are known for their “workhorse” nature, capable of racking up hundreds of thousands of miles with proper care. While later 6-cylinder engines offer slightly improved performance, the 5-cylinder is often lauded for its blend of durability and ease of maintenance, making it a favorite among enthusiasts and those seeking long-term reliability. Models from the late 70s to the mid-80s, such as the 300SD (1978-1979) and the 300D or 300TD (1982-1985), are particularly well-regarded for their robust build quality and enduring appeal.
Key Mercedes Diesel Models to Consider
When exploring the market for the best used Mercedes car, certain diesel models consistently emerge as top contenders. The Mercedes-Benz 300SD from the late 1970s is a prime example. These models are celebrated for their strong diesel engines and comfortable ride. Similarly, the Mercedes-Benz 300D and 300TD from the early to mid-1980s offer a compelling mix of practicality and Mercedes engineering. The “TD” variant, signifying “Touring Diesel,” adds the versatility of a station wagon, making it an even more appealing option for those needing extra cargo space. While aluminum heads were introduced around the mid-to-late 1980s in some models like the W126 chassis 300SD, earlier models predominantly featured all-iron engines, known for their robustness. It’s important to note that while 6-cylinder diesel engines appeared in later models and provide a performance upgrade, they may not match the 5-cylinder’s reputation for sheer durability and ease of DIY maintenance.
Essential Checks When Buying a Used Mercedes Diesel
Mileage is less critical than maintenance history when considering a used Mercedes diesel. A car with meticulous maintenance records is far more valuable than one with low mileage but neglected upkeep. Look for evidence of regular servicing, ideally from a Mercedes-Benz dealer or a reputable independent specialist. Receipts for oil changes, filter replacements, and other routine maintenance tasks are strong indicators of a caring owner. If the previous owner performed their own maintenance, don’t hesitate to ask detailed questions about their practices and even inspect other vehicles they own to gauge their competence.
Visual Inspection is Key: A thorough visual inspection can reveal a lot about a car’s history and how it has been treated. Be wary of cosmetic issues like numerous dents, scratches, missing trim, or a poorly kept interior. These can often be red flags indicating a lack of care in other areas, including mechanical maintenance. While exceptions exist, a neglected exterior and interior can be a strong hint of underlying mechanical neglect. Remember the adage: “There’s nothing more expensive than a cheap Mercedes!” Investing in the best maintained example you can afford will likely save you money and headaches in the long run compared to trying to restore a neglected car.
Specific Areas to Examine:
- Excessive Smoke: Some smoke is normal in older diesels, especially on startup. However, excessive smoke, either at startup or while driving, can signal engine problems.
- Cold Start Performance: A healthy diesel engine should start relatively easily after the glow plug light goes out, even when cold. Difficulty starting could indicate issues with glow plugs, the glow plug relay, low compression, or valve adjustments.
- Heating and Air Conditioning: These systems are known weak points in older Mercedes vehicles and can be expensive to repair. Test both thoroughly.
- Suspension: On cars with over 120,000-150,000 miles, suspension components like bushings, ball joints, and shocks are likely nearing the end of their lifespan. Inspect for wear, as neglecting suspension work leads to premature tire wear, poor handling, and a harsh ride.
- Power Locks and Engine Shut-Off: Check the power locks and ensure the engine shuts off immediately when the key is turned off. Malfunctions in these areas can point to vacuum system leaks, which, while often inexpensive to fix, can be tricky to diagnose.
- Rust: Rust is a major concern and should be avoided if possible. It’s extremely difficult to eradicate once it takes hold. Pay close attention to areas prone to rust, especially in cars from northern regions. Check under carpets and in the trunk for signs of water leaks, which can accelerate rust formation.
- Leaks: Some minor oil leaks are common in older diesels. However, excessive coolant or oil leaks, along with deteriorated hoses and belts, should be addressed as potential problems.
Mileage vs. Maintenance: What Matters Most
It’s not uncommon to find 5-cylinder Mercedes diesel cars with 200,000, 350,000, or even 500,000+ miles still running strong and looking impressive. This longevity is a testament to their robust design and the importance of proper care. The key takeaway is that diligent maintenance trumps mileage. A well-maintained, higher-mileage example is often a better purchase than a low-mileage car that has been neglected. As the original author’s 1979 300SD with 245,000 miles demonstrated – running “like new” – condition and care are paramount. Even without maintenance records, a car’s overall condition, both mechanically and cosmetically, can often speak volumes about its history of care. Mercedes-Benz even acknowledges high-mileage achievements with grille badges awarded at certain mileage milestones, such as 500,000 kilometers.
Conclusion
Finding the Best Mercedes Car in the used market often leads savvy buyers to consider the enduring appeal of older diesel models. Their reputation for durability, combined with relatively simple mechanics, makes them a compelling choice for those seeking reliability and longevity. By prioritizing maintenance history over mileage, conducting thorough inspections, and focusing on well-maintained examples, you can increase your chances of finding a fantastic used Mercedes diesel that will provide years of driving pleasure. Remember to buy the nicest example you can afford, as investing upfront in quality is the most cost-effective approach in the long run when seeking a truly dependable and rewarding used Mercedes-Benz.
