Overheating V6 1997 Mustang

In my experience when a car with an otherwise cooling system in good repair slowly over heats it's usually because the radiator is clogged. So how about the rest of the cooling system? Is it in good repair?

For an older V6 that starts having cooling problems one should keep in the back of your mind "bad head gasket".

But for the P1117 bad wiring or a weak/dirty electrical connection to the ETC should be front and center.

Finally the V6 is bad about trapping air inside the motor. The air will cause the ECT to read low. Did you follow the V6 coolant re-filling procedures EXACTLY?

V6 coolant refilling procedure:
http://www.allfordmustangs.com/foru...stang-irregular-rpms-showing-hot.html#2604913

>>>From the Ford service manual.
P1117 - Engine Coolant Temperature (ECT) Sensor Intermittent

Indicates ECT circuit became intermittently open or shorted while engine was running. Note on some vehicles that are not equipped with an ECT sensor, CHT can be used and can set this DTC.

• Damaged harness
• Damaged sensor
• Damaged PCM
• Damaged harness connector
• Low engine coolant

Monitor ECT or CHT on scan tool, look for sudden changes in reading when harness is wiggled or sensor is tapped