Despite the brand’s reputation for excellence, certain BMW engines have been notorious for reliability issues. While BMW continues to lead in luxury and performance, several of its engines have faced persistent problems that have frustrated owners. From timing chain failures to issues with turbochargers, these engine problems have cost BMW owners both in terms of repair bills and vehicle downtime.
BMW, founded in Munich in 1916, is one of the most respected and recognised car brands globally. Known for its luxurious vehicles that combine performance, technology, and high-end design, BMW cars are often viewed as a symbol of success. The brand has consistently produced cars that deliver impressive horsepower and handling, making them popular among enthusiasts and everyday drivers alike.
However, despite the brand’s reputation for excellence, certain BMW engines have been notorious for reliability issues. While BMW continues to lead in luxury and performance, several of its engines have faced persistent problems that have frustrated owners. From timing chain failures to issues with turbochargers, these engine problems have cost BMW owners both in terms of repair bills and vehicle downtime.
In this article, we will explore the most problematic BMW engines, the common issues they suffer from, and also highlight some of the brand’s most reliable engines.
BMW Engines with Common Reliability Problems
1. BMW 320d 2.0 Diesel Engine (N47D20A and N47D20C)
The BMW 320d 2.0 Diesel engine variants, particularly the N47D20A and N47D20C, are notorious for timing chain failures. These engines, which are found in several BMW models, including the 3 Series and 5 Series, have a reputation for premature timing chain failure due to faulty crankshaft sprockets.
Common Issues:
- Timing Chain Failures: The crankshaft sprockets misalign, causing excessive wear on the timing chain, which eventually snaps, leading to severe engine damage.
- Turbo Issues: Faulty spring in the wastegate causes the turbo to fail or blow up when the spring doesn’t close the wastegate properly, overloading the turbo system.
- Manufacturing Defect: Crankshaft sprockets that drive the timing chain wear out prematurely due to a defect during manufacturing, causing chain failure.
2. BMW 520d 2.0 Diesel Engine (N47D20A and N47D20C)
The BMW 520d 2.0 Diesel shares similar issues with the 320d, particularly around timing chain failures and turbocharger malfunctions. These engines also suffer from the same crankshaft sprocket misalignment issues that cause the timing chain to break.
Common Issues:
- Timing Chain Problems: Just like the 320d, the 520d is vulnerable to the premature failure of the timing chain, caused by misalignment in the crankshaft sprockets.
- Turbo Failure: The turbo wastegate spring fails to close correctly, causing the turbo to be either partially or fully open, which results in excessive wear and eventual failure of the turbo.
3. BMW X5 330d 3.0 Diesel Engine (N57D30A, N57D30B, N57D30C)
The BMW X5 330d 3.0 Diesel engine, particularly in the N57D30A, N57D30B, and N57D30C variants, is known for more severe problems than the 2.0-liter engines. These engines suffer from timing chain issues, turbocharger failures, and injector malfunctions.
Common Issues:
- Timing Chain Failures: The crankshaft sprockets misalign, causing damage to the timing chain. This leads to chain failure, which can cause major damage to the engine.
- Turbo Failures: Issues with the wastegate spring can prevent the turbo from functioning properly, causing the turbo to fail or blow up.
- Injector Failures: The engine suffers from clogged or failed injectors, often caused by contaminated oil or improper maintenance.
- Oil-related Problems: Poor lubrication, often due to dirty oil, leads to turbo failure and reduced engine performance.
Table of BMW Engine Models with Common Problems
| Engine Model | Common Issues |
|---|---|
| BMW 320d 2.0 Diesel (N47D20A, N47D20C) | – Timing chain failure (due to misaligned crankshaft sprockets) – Turbo failure (wastegate spring issue) – Crankshaft sprocket manufacturing defect |
| BMW 520d 2.0 Diesel (N47D20A, N47D20C) | – Timing chain failure – Turbo failure (wastegate spring issue) – Crankshaft sprocket misalignment |
| BMW X5 330d 3.0 Diesel (N57D30A, N57D30B, N57D30C) | – Timing chain failure (misaligned crankshaft sprockets) – Turbo failure (wastegate spring malfunction) – Injector failure – Oil lubrication issues |
| BMW X5 330d 3.0 Diesel (M57D30) | – Turbo failure (due to poor oil lubrication) – Injector failure – Reduced engine performance |
| BMW 1 Series 2.0 Diesel (N47) | – Timing chain failure – Turbo failure (wastegate issues) – Excessive engine noise due to chain tension |
BMW Engines Known for Reliability
While some BMW engines have been prone to failures, the brand has also produced a number of engines that are known for their durability and reliability. These engines typically feature better design, more robust components, and fewer known issues over their lifespan.
1. BMW 3.0L Inline-Six Engine (N52)
The N52 engine, a naturally aspirated inline-six, is one of BMW’s most reliable engines. It’s known for its smoothness, longevity, and overall performance.
Common Strengths:
- Longevity: With regular maintenance, the N52 engine is known to last for hundreds of thousands of miles without significant issues.
- No Major Design Flaws: Unlike some of the diesel engines, the N52 doesn’t suffer from timing chain or turbo issues.
- Smooth Performance: The inline-six configuration provides excellent balance, reducing vibrations and improving engine smoothness.
2. BMW 2.0L Turbocharged Four-Cylinder (B48)
The B48 engine, part of BMW’s modular engine family, has proven to be reliable in various models such as the 320i and 330i. This engine offers a good balance between power and fuel efficiency.
Common Strengths:
- Efficiency: Excellent fuel economy with strong performance for a four-cylinder engine.
- Low Maintenance: Compared to the diesel engines, the B48 has fewer issues with common components like the timing chain or turbo.
- Performance: Provides a good amount of power and responsiveness without being over-stressed, leading to longer engine life.
3. BMW 3.0L Turbocharged Inline-Six (B58)
The B58 is a newer turbocharged inline-six engine used in models like the BMW Z4, 330i, and 540i. It’s known for its reliability and powerful performance.
Common Strengths:
- Improved Design: The B58 has addressed many of the issues seen in earlier BMW engines, such as turbo reliability.
- Power and Efficiency: Provides excellent horsepower and torque without sacrificing fuel economy.
- Low Failure Rate: The B58 engine has a much lower failure rate compared to BMW’s previous turbocharged engines, making it one of the most reliable powertrains.
4. BMW 6.6L V12 (N73)
The N73 V12 engine, used in higher-end BMW models like the 7 Series, is a robust and powerful engine that has shown impressive longevity when properly maintained.
Common Strengths:
- Durability: The N73 engine is known for its long lifespan, often exceeding 200,000 miles with minimal problems.
- Smooth Power Delivery: As with most V12 engines, the N73 is exceptionally smooth and delivers powerful performance without strain.
- Fewer Common Failures: While the V12 is a complex engine, it is less prone to the widespread issues seen in smaller, turbocharged engines.
Table of BMW Engine Models Known for Reliability
| Engine Model | Common Strengths |
|---|---|
| BMW 3.0L Inline-Six (N52) | – Excellent longevity – No major design flaws – Smooth performance |
| BMW 2.0L Turbocharged Four-Cylinder (B48) | – Strong power and efficiency – Low maintenance – Reliable turbo performance |
| BMW 3.0L Turbocharged Inline-Six (B58) | – Improved design with fewer issues – Powerful yet fuel-efficient – Low failure rate |
| BMW 6.6L V12 (N73) | – Highly durable and long-lasting – Smooth power delivery – Minimal common failures |
Conclusion: BMW’s Balance of Luxury and Reliability
BMW cars are synonymous with luxury, performance, and cutting-edge technology. However, like many high-performance brands, BMW has faced its share of engine issues, particularly with certain diesel engines. Models like the 320d, 520d, and X5 330d have been plagued with timing chain failures, turbo problems, and oil lubrication issues, which have resulted in costly repairs for owners.
On the other hand, BMW has produced some remarkably reliable engines as well, such as the N52, B48, and B58engines, which are known for their durability and low-maintenance needs. When choosing a BMW, prospective buyers should consider both the performance and reliability of the engine to ensure they are getting the most value for their investment.
In conclusion, while BMWs are some of the best-driving cars in the world, it’s important to be aware of the potential issues with certain engine models. By researching and understanding common problems, you can make an informed decision and enjoy the performance and luxury that BMW offers without unexpected repair costs.