The N55 engine's cooling system, particularly the **water pump** and **thermostat housing**, can develop leaks over time. These issues are common in higher-mileage examples. Estimated repair cost: $500 - $1,500.

The **turbocharger** and its associated **wastegate actuator** can experience wear, leading to reduced performance or boost leaks. This is a known concern for turbocharged engines of this era. Estimated repair cost: $1,500 - $3,000.

Fuel Injector Problems

Direct-injection fuel injectors can become clogged or fail, leading to misfires and rough idling. This is a common issue with GDI engines. Estimated repair cost: $800 - $1,600.

CARFOCALvehicle research

2014 BMW 640i Maintenance guide

Name: Maintenance dataset for 2014 BMW 640i
Creator: Carfocal

v1.0Updated Jul 4, 2026Ethan Miller4 Sources Analyzed

MAINTENANCE SUMMARY

The 2014 BMW 640i, with an 'Average' reliability verdict and 191 TSBs, demands diligent maintenance. Owners should anticipate potential issues with cooling systems, turbochargers, and electronic control modules, particularly past 60,000 miles.

View Critical Issue: Turbocharger Issues

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Reliability Score

Est. Annual Maintenance Cost

$1,200 - $2,000

TSBs & Recalls

191 TSBs | 0 Recalls

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Create a free account to reveal the full service schedule, repair costs, and deeper diagnostic data.

Key Takeaways

Average reliability with a high TSB count suggests proactive maintenance is key.
Potential issues include cooling system leaks and turbocharger wear.

2 more takeaways unlock below

Critical service intervals

Common failure analysis

Symptoms and prevention guidance

2014 BMW 640i Maintenance guide

v1.0Updated Jul 4, 2026Ethan Miller4 Sources Analyzed

MAINTENANCE SUMMARY

View Critical Issue: Turbocharger Issues

Subscribe to Recall Alerts Subscribe to Recall Alerts

Reliability Score

Est. Annual Maintenance Cost

$1,200 - $2,000

TSBs & Recalls

191 TSBs | 0 Recalls

CarFocal account required

Unlock the Full 2014 BMW 640i Maintenance Guide

Create a free account to reveal the full service schedule, repair costs, and deeper diagnostic data.

Key Takeaways

Average reliability with a high TSB count suggests proactive maintenance is key.
Potential issues include cooling system leaks and turbocharger wear.

2 more takeaways unlock below

Critical service intervals

Common failure analysis

Symptoms and prevention guidance