BMW N57 Problems

The BMW N57 is a family of aluminium, turbocharged straight-six common rail diesel engines. The engines have been widely used across BMW’s luxury car lineup and have garnered a reputation for high performance and reliability. However, as with any engine, the N57 has its potential issues. This article sheds light on the common problems experienced by users and provides insights into possible solutions.

Reliability and Comparison

1. Overall Reliability:
   • Generally, the N57 is seen as a reliable engine. However, some suggest that it might not be as durable as the older M57, but it does fare better than the N47.
2. Comparison to M57:
   • The M57 has been considered a benchmark for BMW’s straight-six diesel engines in terms of reliability. In comparison, the N57 might fall slightly short but is generally seen as more reliable than the problematic N47.
3. Ex Police N57 Engines:
   • It’s noteworthy that ex-Police N57 engine cars are often available for sale, some of which might have had a new engine or are in need of one.

Timing Chains & Components

1. Concerns:
   • One of the primary concerns voiced about the N57 engine is related to its timing chains. While they are believed to be more reliable than those in the N47, they can still become a concern, especially around 100k miles.
2. Components:
   • The N57 and N47 share the same chain, tensioner, and a guide rail, but not the sprockets. These components have seen multiple revisions, with the latest revision being introduced in March 2014.
3. Recommendation:
   • If the engine has clocked around 150k miles, it’s advisable to replace the chain and guides. Moreover, hard-driven cars, especially models like the 535d, might experience crankshaft issues.

DPF (Diesel Particulate Filter)

1. Longevity:
   • BMW DPFs are generally robust and don’t need replacements. However, if they get blocked due to engine operation faults, they can either undergo a forced regeneration or a chemical clean.
2. Misunderstandings:
   • Some mechanics might not have a complete understanding of DPFs and might replace them without fixing the primary issue, leading to recurrent problems.

EGR Valves & Turbos

1. EGR Valve Issues:
   • Sticky EGR valves are a known concern with the N57. Regular servicing can help prevent these issues.
2. Turbos:
   • Turbos on the N57, especially the low-pressure ones, might need replacements after a certain mileage. For instance, some users have reported needing a new turbo around 165k miles.

General Recommendations

1. Service History:
   • Frequent servicing can play a significant role in the longevity and performance of the N57. Engines with regular maintenance checks often face fewer issues.
2. Automatic Transmission:
   • For those opting for an automatic transmission, ensure that the gearbox changes smoothly. Some users have reported dissatisfaction even after changing the oil and filter.
3. Extended Warranty:
   • Given the potential issues and the high repair costs associated with luxury cars, considering an extended warranty might be a good idea.

Conclusion

The BMW N57 engine offers a blend of performance and efficiency. While it is generally seen as reliable, being informed about its potential weak points can help owners prevent problems or address them promptly. Regular servicing, combined with a proactive approach towards component wear, can ensure that the N57 offers many miles of smooth driving.