Discover the 8 Worst BMW Engines to Avoid

Patrick Oziegbe
Updated On:

When it comes to BMW engines, reliability is a critical factor to consider as a car enthusiast.

As you explore the vast range of options, knowing which engines to avoid can help steer you in the right direction, ensuring a smooth and enjoyable driving experience.

In this article, we’ll dive into BMW engines that have earned a reputation for being less reliable and discuss the underlying issues that affect their performance.

This information will aid you in making informed decisions when considering a used auto engine to land  the most reliable BMW engine in the market!

Problematic BMW Engines

Issues with Specific Models

N54 engine

When it comes to the N54 engine, used in models from 2007-2010 like the 335i, you might experience issues such as fuel injector leaks and water pump failure. This engine, despite its impressive performance, has been known to have reliability problems.

N52 engine

The N52 engine from the E90 series, utilized in models like the 328i and 330i, has had reported problems with electric water pumps and oil leaks.

In particular, the E90 325i model is one to be cautious of, as issues like this can lead to costly repairs.

M54 engine

The M54 engine, found in E46, E39, and Z3 models, is another engine to be wary of. It is known for its cooling system problems, like failed water pump and leaking expansion tanks. Additionally, the E46 series suffered from VANOS and subframe issues.


Another problematic engine is the N20, mainly found in 2012-2015 4-cylinder BMW models like the X3 and Z4. Issues with this engine include timing chain problems and oil consumption. Discover more BMW Z4 issues as explained here.

Common Problems and Failures

Rod bearings have been an issue with various BMW engines, such as the M60 V8 and M54 engines.

When these bearings wear out, there’s increased friction between the bearing and the crankshaft, which can lead to engine failure if not addressed in time. Keep an ear out for unusual noises in your car.

Another common issue is VANOS failure. It’s a variable valve timing system found in many BMW engines, including the E46, E60, and E63 models.

If your VANOS system fails, it can cause decreased performance and fuel efficiency. To avoid significant issues, it is essential to attend to any signs of VANOS failure.

Cooling system problems are frequently encountered in BMW engines. Radiators, water pumps, and expansion tanks tend to fail over time due to the high heat cycles these components go through.

Stay vigilant in checking and maintaining your cooling system to avoid overheating and engine damage.

Specific BMW Models to Avoid

BMW Models with High Engine Failure Rates

It’s essential to be aware of some BMW models with high engine failure rates. One of the models to avoid is the BMW 335i, mainly due to its problematic N54 engine.

Another model to watch out for is the BMW 520d 2.0 Diesel, which has several reported engine issues. The same goes for the following vehicles:

  • BMW X5 330D 3.0
  • BMW 320d 2.0 Diesel
  • 116i BMW 1 Series
  • 118i BMW 1 Series
  • 316i BMW 3 Series
  • 120i BMW 1 Series
  • 220i BMW 2 Series
  • 520i BMW 5 Series

Avoiding these models can help you steer clear of potential headaches down the road.

Diesel vs Petrol Engines

When choosing between diesel and petrol engines, consider the trade-offs in performance, fuel economy, and potential issues.

Diesel engines generally offer better fuel economy, but they may also come with their own set of problems. For example, the BMW X5 330D 3.0 diesel engine has been known to experience issues, making it one to avoid.

On the other hand, petrol engines, like the one found in the BMW M5 and BMW M6, have had their own share of problems, including engine oil leaks and overheating. However some BMW M5 problems are different then M6 car.

Ultimately, it’s up to you to weigh the pros and cons of each engine type and decide which best suits your needs and preferences.

Maintenance and Repair Concerns

Maintenance Costs and Expenses

Maintaining a BMW can be expensive, especially if you own a model with known engine problems. Some issues, like timing chain failure or turbo failure, require costly repairs.

Additionally, BMW diesel engines may need frequent injector replacements. Keep in mind that high-quality parts and regular maintenance can help extend your engine’s life.

High-Wear Parts and Components

Several parts in BMW engines are prone to wear, like the valve cover gasket and water pump in the cooling system.

The VANOS system in the cylinder head and timing chains on certain models, like the X1 and 5 Series, may also require replacement. Regularly check these components to prevent more significant issues in your BMW.

Preventative Measures and Care

Routine Maintenance Recommendations

Keep your BMW in top shape by regularly replacing ignition coils, fuel injectors, and spark plugs. Use high-quality fuel to prevent carbon build-up and engine failure. Keep an eye on the health of your inline-6, turbocharged engine, and DISA valve.

Identifying Potential Issues

Monitor your X5 or F30 ABS module. For issues on E46 models, use the OBD-II port to check for error codes.

Avoid high-sulfur gasoline or fuel injection problems to ensure better reliability and reduce the likelihood of a costly repair.

Comparing BMW Engines to Competition

How Other Brands Compare to BMW Engines

When looking at competitors, your focus will likely be on other luxury brands, such as Mercedes-Benz, Audi, and Lexus.

While all have their strengths and weaknesses, BMW engines are often praised for their power and driving dynamics. However, it’s essential to weigh the pros and cons to find the engine that best suits your needs.

Modern BMW Engines and Reliability

Contemporary BMW engines benefit from advanced technology and design, making them more efficient and powerful than their predecessors.

Some popular options include the BMW X5 330d 3.0 engine, BMW 320d 2.0 diesel engine, and engines found in vehicles like the BMW 1 Series 118i and 116i.

Yet, when it comes to reliability, some engines face more significant challenges than others.

The N52 inline-6 found in the E90 325i, 328i, and 330i is a dependable engine known for its durability. Other reliable options include the M54 inline-6 and M44 4-cylinder engine.

However, some 2009 models may experience issues with their engines, so it’s crucial to do thorough research on specific vehicles before making a purchase.

Notable engines that require extra care are the BMW X5 330d 3.0, BMW 320d 2.0 diesel, BMW 520d 2.0 diesel, and 520i BMW 5 Series issues.

Regular maintenance and prompt attention to any problems will help ensure these engines perform optimally and remain reliable.

To sum up, as a discerning buyer, consider all available information on various models and their respective engines. Remember to prioritize factors like performance, reliability, and overall satisfaction to make an informed decision about your next vehicle.

Frequently Asked Questions

Most problematic BMW engines?

Some of the most problematic BMW engines include the X5 4.8i (2007-2010), 750i and 750Li (2006-2008), and the 745i and 745Li (2002-2005). These engines are known for their issues with leaking oil and smoke in the engine compartment and exhaust.

BMW engines with timing chain issues?

BMW timing chains are known for breaking down prematurely. Proper attention to oil quality can reduce this risk. Be mindful of any signs of timing chain failure when considering a BMW purchase.

Least reliable BMW diesels?

The BMW X5 330D 3.0, BMW 320d 2.0 Diesel, and BMW 520d 2.0 Diesel are some of the least reliable BMW diesel engines. Issues with these engines can lead to costly repairs and poor performance.

Best and worst BMW 4-cylinder engines?

The N20 engine is among the best BMW 4-cylinder engines, being both efficient and powerful. One of the worst BMW 4-cylinder engines is the 116i BMW 1 Series, which has various issues leading to a subpar driving experience.

BMW engine reliability ranking?

While it’s difficult to establish a definitive ranking for BMW engine reliability, some reliable choices include the M60 V8 and the 3.0-liter and 4.0-liter M62 engines, found in models such as the E34 5 Series and the E32 7 Series.

On the other hand, the N63 engine, found in xDrive50i models, has been linked to a class-action lawsuit and is best avoided.


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