1. Technical Service Bulletins

Flushing F-150 Heater Core System

April 26, 2023
Photo: Ford
This condition may be due to deposits from the engine coolant becoming trapped in the heater core. Flush the system and replace the heater core.
This condition may be due to deposits from the engine coolant becoming trapped in the heater core. Flush the system and replace the heater core.

Some 2015-2019 Ford F-150 trucks equipped with a 3.3L, 3.5L Duratec, 3.5L EcoBoost or 5.0L engine without a block heater and built on or before Jan.1, 2019 may exhibit a lack of heat concern from the HVAC system when operating the vehicle in temperatures below four degrees Fahrenheit. 

This condition may be due to deposits from the engine coolant becoming trapped in the heater core. Flush the system and replace the heater core.

Also replace the thermostatic expansion valve manifold O-rings P/N 6E5Z-19E889-D and 6E5Z-19E889-E, thermostat O-ring seal (on 3.5L EcoBoost), thermostat O-ring seal (on 5.0L, 3.3L and 3.5L Duratec), heater core FL3Z-18476-B, steering shaft bolt N808684-S101, front seat bolt W718633-A451 and heater core line clips BC3Z-8287-C. 

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