There are 1 owner-reported engine complaints for the 2017 Ford Flexin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
I am submitting this complaint to report a serious and potentially dangerous safety defect involving the internal water pump design in the 3.5L Duratec V6 engine used in my 2017 Ford Flex. The water pump in this engine is mounted internally behind the timing chain cover. When the pump fails, coolant is not externally visible but instead leaks directly into the engine oil. This design prevents early detection and warning, leading to rapid and catastrophic engine failure without adequate notice to the driver. In my case, the water pump failed suddenly, allowing coolant to contaminate the engine oil. This resulted in total engine failure and immediate loss of vehicle operability.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026