Flushing F-150 Heater Core System

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 may exhibit a lack of heat concern from the HVAC system when operating the vehicle in temperatures below four degrees Fahrenheit.

Information courtesy of Mitchell 1

April 26, 2023

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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Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.