Purchasing a used luxury car can feel like stepping into a world of premium comfort and performance without the hefty price tag of a new model. The Mercedes-Benz S-Class, especially the 2007 Mercedes Benz S Class S550 Amg (and its non-AMG counterpart), often appears as an enticing option in the used car market. Boasting sophisticated technology, a smooth ride, and the prestige of the Mercedes-Benz brand, it’s easy to see the appeal. However, beneath the surface of this seemingly luxurious bargain lies a potential pitfall that could turn your dream car into a financial nightmare.
Having spent years in the used car industry, I’ve seen firsthand how certain vehicles, despite their initial allure, can become money pits for unsuspecting buyers. While the 2007 Mercedes Benz S Class S550 AMG might catch your eye with its attractive price point and opulent features, it’s crucial to be aware of a significant engine issue that plagued this model year. This isn’t just about minor repairs or expected maintenance; we’re talking about a flaw that could lead to catastrophic engine failure.
Many car enthusiasts are familiar with the notorious engine problems in certain BMW and Audi models. But it’s important to understand that even brands renowned for their engineering prowess, like Mercedes-Benz, are not immune to design flaws. The 2007 Mercedes S550, the flagship sedan intended to solidify Mercedes-Benz’s position in the luxury car market, unfortunately, carries a significant risk due to a critical engine component.
When the 2007 S-Class debuted, it was lauded for its elegant design, exceptional ride comfort, and cutting-edge technology. Features like multiple massage settings in the seats and an array of electronic gadgets made it a highly desirable vehicle for affluent buyers. Now, nearly two decades later, these models can be found at significantly lower prices, often between $15,000 and $20,000. This price drop might seem like an incredible opportunity to own a piece of luxury engineering. However, before you jump at what seems like a bargain, you need to understand the hidden danger lurking within the engine bay of the 2007 Mercedes Benz S Class S550.
While common issues with Mercedes-Benz models of this era, such as air suspension malfunctions and electronic glitches, are well-documented and often manageable with a skilled independent mechanic or a DIY approach for those mechanically inclined, the real Achilles’ heel of the 2007 Mercedes S550 lies deeper within the engine itself.
The culprit is a small, seemingly insignificant gear located inside the M273 V8 engine of the 2007 Mercedes S550. This gear, connected to the engine’s timing chain, was manufactured with substandard metal. Over time, this inferior material can lead to premature wear and tear, causing the teeth of the gear to degrade and eventually fail. This is not a matter of if, but when, for many of these engines.
The initial warning signs of this impending engine disaster often appear as a check engine light accompanied by camshaft timing codes. Ignoring these warnings, a common mistake among subsequent owners of used luxury vehicles, will lead to increasingly noticeable engine imbalance. The engine will start to vibrate and run roughly, signaling the gear’s progressive decay.
If the vehicle continues to be driven despite these increasingly severe symptoms, the consequences can be catastrophic. As the gear deteriorates further, the timing chain can slip, leading to a collision between pistons and valves. This internal engine damage is severe and often results in complete engine failure. Imagine the dramatic engine failure scene from the movie Michael Clayton – that’s the potential reality facing owners of a 2007 Mercedes S550 with this issue.
Replacing a damaged engine is a costly undertaking. The price of a used M273 engine, coupled with labor costs for installation, can easily reach upwards of $6,500 or more. For that amount, you could potentially lease a brand new, more reliable vehicle.
Even if you are proactive and decide to replace the faulty gear before catastrophic failure occurs, the repair process is far from simple. Despite being a small and inexpensive part, accessing and replacing this gear is a labor-intensive job. As illustrated in online repair guides, the process involves a significant amount of engine disassembly:
- Step 1: Remove the engine from the vehicle.
- Step 2: Disassemble numerous engine components, including cam covers, secondary air pump, pulleys, thermostat housing, oil filter case, vibration damper, water pump, coils, valve covers, timing chain adjuster, and timing cover, to reach the gear.
- Step 3: Replace the faulty gear.
- Step 4: Reassemble all the components, ensuring everything is correctly positioned and torqued.
This complex procedure highlights why even a seemingly minor part failure can result in a major and expensive repair. Entrusting this job to a Mercedes-Benz dealership will likely result in a substantial bill due to the extensive labor hours involved.
It’s crucial to note that this engine gear issue was not limited to just the 2007 Mercedes S550. A wide range of Mercedes-Benz models from the 2006 and 2007 model years, equipped with specific serial number ranges of V6 (M272) and V8 (M273) gasoline engines (excluding AMG models), were affected by this manufacturing defect. The V6 engines also suffered from similar defective gears in their balance shafts, leading to comparable engine problems.
For owners of less valuable models from this era, such as a 2006 C-Class, the repair costs associated with this engine issue could easily exceed the car’s market value, making repair economically unviable.
While the probability of this gear failure might be statistically comparable to a low-stakes game of Russian Roulette, the potential consequences are severe enough to warrant serious consideration. Why take the risk when a readily available and reliable alternative exists?
The solution is straightforward: if you’re considering a used Mercedes-Benz S-Class, opt for a 2008 or newer model. Mercedes-Benz rectified this engine flaw in subsequent model years by using stronger, more durable materials for the timing chain gear. They also addressed the issue through a class-action lawsuit settlement. By choosing a 2008 or later model, you significantly mitigate the risk of encountering this potentially devastating and costly engine problem.
In conclusion, while the 2007 Mercedes Benz S Class S550 AMG (and non-AMG versions) may appear tempting on the used car market due to their luxurious features and depreciated prices, the inherent risk of catastrophic engine failure due to a faulty timing chain gear makes it a vehicle to approach with extreme caution, if not avoid altogether. Protect yourself from potential financial hardship and consider a later model year S-Class for a more reliable and worry-free ownership experience.
