Some 2015-2016 Lincoln Navigator vehicles equipped with a 3.5L gasoline turbocharged direct injection (GTDI) engine may exhibit a hard-to-start or a no-start condition after using the block heater when temperatures are below 0 degrees. 

Remove and discard the existing cooling system heater and wire harness. Install an immersion block heater and harness kit5 P/N FL3Z-6D008-A. Instructions are included with the kit. It is not necessary to remove the left-hand turbocharger assembly. Use special tool 303-1638 to install the immersion block heater. Fill the cooling system. Recommend to the customer to plug the block heater in when temperatures are at or below 0 degrees to improve cold starting.