BMW built a name for themselves building not only some iconic cars, but also some marvelous engines. Over the decades, BMW was also known for producing some of the most refined and powerful engines in the automotive industry. But which ones are the most reliable? In this article, we will rank the top five BMW engines ever made based on their durability, performance and customer satisfaction. The article is based on our own experience with some of these engines and from customer feedback collected through various online mediums.
The N52 was a naturally aspirated inline-six engine that debuted in 2004 and replaced the M54. It featured a magnesium-aluminum composite block, variable valve timing and lift, and direct injection. The N52 was praised for its smoothness, responsiveness and fuel efficiency. It was also one of the lightest six-cylinder engines in its class, weighing only 161 kg. The N52 powered many models, such as the E90 3 Series, E60 5 Series, E83 X3 and E70 X5. The most common issues with the N52 were oil leaks, water pump failures and carbon buildup. However, these problems were not very frequent and could be prevented with proper maintenance. The N52 was retired in 2015 and replaced by the turbocharged N20 and N26.
The M57 was a turbocharged diesel inline-six engine that debuted in 1998 and replaced the M51. It featured a cast iron block, common rail injection, variable geometry turbocharger and intercooler. The M57 was renowned for its torque, economy and longevity. It was also one of the most popular diesel engines in Europe, where it accounted for more than half of BMW’s sales. The M57 powered many models, such as the E46 3 Series, E39 5 Series, E53 X5 and E65 7 Series. The most common issues with the M57 were swirl flap failures, injector failures and glow plug failures. However, these problems were not very serious and could be fixed with relatively low costs. The M57 was retired in 2013 and replaced by the N57. The N57 could have easily been on this list at number 4 since it was nearly as remarkable.
The S54 was a naturally aspirated inline-six engine that debuted in 2000 and replaced the S50. It featured a cast iron block, forged steel crankshaft, individual throttle bodies, variable valve timing and lift, and dual VANOS. The S54 was acclaimed for its high-revving nature, power output and sound. It was also one of the most awarded engines of its time, winning the International Engine of the Year award in 2001 and 2002. The S54 powered some of the most iconic BMW models, such as the E46 M3, E36/8 Z3 M Coupe and Roadster, and E85 Z4 M Coupe and Roadster. The most common issues with the S54 were rod bearing failures, VANOS failures and oil consumption. However, these problems were not very common and could be avoided with proper care and frequent oil changes.
The S54 was retired in 2008. Notably, there is no true successor to the S54. The S65 V8 found in the next M3 is much more closely related to the S85 V10 than the S54. The newer S55 and S58 engines are based largely off of the N54, which did not share much with the S54. Therefore, the S54 represents the coalescence of over six decades of BMW fine-tuning their original inline six formula; and its fairly likely that that will forever make it one of a kind.
To cement its legacy, the BMW S54 was also used in the legendary “M3 CSL” guise. In that special M3, the S54B32HP was up to 350 horsepower, thanks to some revised engine bits.
The M30 was a naturally aspirated inline-six engine that debuted in 1968 and replaced the M10. It featured a cast iron block, aluminum head, single overhead camshaft, Bosch fuel injection and distributor ignition. The M30 was admired for its smoothness, reliability and simplicity. It was also one of the longest-lived BMW engines ever made, lasting for more than 20 years and powering more than one million vehicles. The M30 powered many models, such as the E3 2500-3.3 Li, E9 2800-3.0 CSi, E12 5 Series, E24 6 Series and E28 5 Series. The most common issues with the M30 were oil leaks, timing chain wear and valve stem seal wear. However, these problems were not very severe and could be easily fixed with regular servicing. The M30 was retired in 1991 and replaced by the M50.
Oh! The holy grail – a naturally aspirated V8 engine! The S65 debuted in 2007 and replaced the S62. It featured a lightweight aluminum block, forged steel crankshaft, individual throttle bodies, variable valve timing and lift, and quad VANOS. The S65 was praised for its high-revving character, power delivery and sound. It was also one of the most advanced BMW engines ever made, featuring technologies such as brake energy regeneration, oil level sensor and knock control. The S65 powered only one model: the E90/E92/E93 M3. An enlarged version of the S65 was also used in highly limited models, like the BMW E92 M3 GTS and BMW E90 M3 CRT. The P65 racing engine is also based on the S65 and was used in the BMW M3 ALMS, M3 GT2, Z4 GT3 and Z4 GTE racing car.
The most common issues with the S65 were rod bearing failures, throttle actuator failures and idle control valve failures. However, these problems were not very frequent and could be minimized with proper maintenance and quality oil. The S65 was retired in 2013 and replaced by the turbocharged S55.
Certainly, like many top 5 lists, certain entries may involve subjective opinions. Therefore, we invite you to share your thoughts and insights on what you believe constitute some of the most reliable BMW engines ever built.