The Ultimate Guide to the Mercedes M273 Engine: Specs, Reliability, and Common Issues
The Mercedes-Benz M273 engine represents a significant evolution in the automotive world, showcasing the brand’s commitment to engineering excellence. Launched in 2005, the M273 family includes both 5.5-liter and 4.7-liter V8 engines, which have powered a range of luxury models from the prestigious German automaker. With a focus on performance, reliability, and smooth operation, the M273 has made its mark in the automotive industry. However, like any engine, it has its strengths and weaknesses. This guide aims to provide an in-depth look at the M273 engine, including specifications, common problems, and maintenance tips to ensure it runs smoothly.
Comparison of Mercedes M273 Engine Variants
| Engine Variant | Displacement | Configuration | Applications | Key Features |
|---|---|---|---|---|
| M273 55 KE | 5.5 L | V8 | S-Class, CL-Class, G-Class | High power output, performance-focused |
| M273 46 KE | 4.7 L | V8 | E-Class, CLS-Class, GL-Class | Efficient power delivery, refined experience |
Overview of the Mercedes M273 Engine Family
The M273 engine family was developed as a successor to the M113 engine, marking a transition towards more advanced technologies in Mercedes vehicles. The M273 is a naturally aspirated V8, renowned for its smooth power delivery and refined engineering. The engines are constructed entirely from aluminum, which contributes to their lightweight and enhances performance.
Design and Engineering Features
The M273 engines incorporate several advanced design features:
- All-Aluminum Construction: Both the 5.5L and 4.7L variants are made from aluminum, which reduces weight and enhances fuel efficiency.
- V8 Configuration: The engines feature a 90-degree V-angle, providing a balanced and smooth operation.
- Variable Valve Timing: This technology optimizes performance across different RPM ranges, ensuring efficient power delivery.
Technical Specifications
The following table outlines the technical features of the Mercedes M273 engine:
| Feature | M273 55 KE | M273 46 KE |
|---|---|---|
| Displacement | 5.5 L | 4.7 L |
| Bore x Stroke | 98.0 mm x 90.5 mm | 92.9 mm x 86.0 mm |
| Compression Ratio | 10.5:1 | 10.7:1 |
| Power Output | 382 hp | 335 hp |
| Torque | 391 lb-ft | 339 lb-ft |
| Valvetrain | DOHC, 4 valves per cylinder | DOHC, 4 valves per cylinder |
Performance Characteristics
The M273 engine family is designed to deliver a powerful and engaging driving experience. The 5.5-liter variant, known for its robust performance, offers impressive horsepower and torque figures, making it ideal for high-end models like the S-Class and CL-Class. On the other hand, the 4.7-liter variant strikes a balance between performance and efficiency, making it suitable for a wider range of vehicles, including the E-Class and CLS-Class.
Common Problems and Issues
While the M273 engine is generally reliable, it is not without its issues. Here are some common problems associated with this engine family:
1. Intake Manifold Failures
One of the most frequently reported issues with the M273 engine is the failure of the intake manifold. The plastic components can warp or crack over time, leading to vacuum leaks and performance issues.
2. Camshaft Adjuster Wear
Another common problem is the wear of the camshaft adjusters. This can result in poor engine performance and an increase in engine noise, especially at higher RPMs.
3. Oil Leaks
Oil leaks can occur due to aging seals and gaskets, particularly around the valve covers. Regular maintenance and inspections can help mitigate this issue.
4. Cooling System Issues
The M273 engine’s cooling system relies on an electronically controlled thermostat. In some cases, failure of this component can lead to overheating, which can severely damage the engine.
5. Fuel Injection Problems
Issues with the sequential fuel injection system can lead to poor fuel economy and rough idling. Regular cleaning and maintenance of the fuel injectors can help prevent these problems.
Maintenance Tips for M273 Engine Owners
To ensure the longevity and reliability of your Mercedes M273 engine, consider the following maintenance tips:
- Regular Oil Changes: Change the engine oil and filter regularly to keep the engine lubricated and running smoothly.
- Monitor Cooling System: Check the coolant levels and inspect the cooling system components for any leaks or failures.
- Inspect Intake Manifold: Regularly inspect the intake manifold for signs of wear or cracking, and replace it as necessary.
- Check for Oil Leaks: Keep an eye out for oil leaks around the valve covers and ensure that seals and gaskets are in good condition.
- Fuel Injector Cleaning: Regularly clean the fuel injectors to prevent clogging and maintain optimal performance.
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Conclusion
The Mercedes M273 engine family has made a significant impact in the luxury automotive market, offering a blend of performance and refinement. While it has its share of common problems, proactive maintenance can help ensure a smooth and reliable driving experience. Understanding the specifications and potential issues associated with the M273 will empower owners to take the necessary steps to maintain their vehicles effectively.
FAQ
What is the Mercedes M273 engine?
The Mercedes M273 engine is a naturally aspirated V8 engine family that includes 5.5-liter and 4.7-liter variants, introduced in 2005 as successors to the M113 engine.
What vehicles are equipped with the M273 engine?
The M273 engine has been used in several luxury models, including the S-Class, E-Class, CL-Class, G-Class, and GL-Class.
What are the common problems with the M273 engine?
Common issues include intake manifold failures, camshaft adjuster wear, oil leaks, cooling system problems, and fuel injection issues.
How often should I change the oil in my M273 engine?
Regular oil changes are recommended every 7,500 miles or according to your vehicle’s service manual, depending on driving conditions.
Can I use synthetic oil in the M273 engine?
Yes, synthetic oil is often recommended for the M273 engine, as it provides better lubrication and can improve engine performance.
What is the power output of the M273 5.5L variant?
The M273 5.5L variant, known as the M273 55 KE, produces approximately 382 hp and 391 lb-ft of torque.
Is the M273 engine reliable?
While the M273 engine is generally reliable, it is known to have some common issues that require attention and maintenance.
How can I prevent oil leaks in my M273 engine?
Regular inspections of seals and gaskets, along with timely oil changes, can help prevent oil leaks in the M273 engine.
What is the expected lifespan of the M273 engine?
With proper maintenance, the M273 engine can last well over 150,000 miles.
What advancements did the M273 engine introduce over the M113?
The M273 engine introduced improvements such as an all-aluminum construction, variable valve timing, and enhanced fuel efficiency compared to its predecessor, the M113.