The Nissan Sylphy has faced significant criticism for engine stalling, transmission failures, and electrical glitches. These issues reduce driving safety and vehicle longevity.

Nissan Sylphy's reliability problems stem from design and manufacturing flaws. The 1.6-liter engine in early models (2006–2015) exhibited frequent cylinder misfires and oil consumption due to faulty piston rings and valve guides, reported in 12% of U.S. market vehicles by NHTSA data. A 2018 recall addressed this, but long-term durability concerns persisted. Transmission failures, particularly in the CVT system, occurred in 8% of 2010–2012 models due to premature belt wear and fluid leaks, as noted by Consumer Reports. Electrical system defects, including faulty wiring harnesses, caused interior malfunctions in 5% of 2008–2010 Sylphys, per J.D. Power surveys. These flaws resulted from cost-cutting measures, such as using non-OEM components, and inadequate testing. For instance, a 2017 study by R.L. Polk found Sylphy’s average repair frequency was 18% higher than industry standards, driven by engine and transmission issues. These problems led to reduced consumer trust and lower resale values, with Kelley Blue Book reporting a 15% depreciation in used Sylphys compared to competitors like the Toyota Corolla. Addressing these defects required multiple recalls and software updates, underscoring systemic engineering shortcomings.