96 Cobra And Az Temp

FWIIW the stock T-stat is 192 degrees. A motor coolant temperature of 218 degrees isn't over heating. In fact the high speed fan won't even kick on until about that point.

Does your cooling fan actually WORK on both speeds? It seems to me that is the question you should be answering.

Are all of the fan shrouds and air dams in place?

Just wondering..... Does the motor actually over heat if driven long distances at expressway speeds?

Again. a motor at 220 degrees is not overheating. The cooling system is working as Ford designed it IF the temperature comes down when the high speed cooling fan turns on. The Motor would continue to get hotter IF the radiator isn't able to keep up.

Note, I have helped more than one person who thought the motor was over heating when in fact it was not. The problem turned out to be electrical in nature. The dash gauge is affected by system voltage. When the voltage drops the dash gauge reads higher.

This is why it's a good idea to cross check using all available information. IE a motor that is overheating will have other symptoms of over heating. For example:

• Coolant boiling.
• Excessive pressure.
• Misfire.
• Poor motor performance.
• cross check with a scanning infrared thermometer at the T-stat housing.
• The engine bay will just "feel" hot when the hood is opened.

Suggest having the alternator and battery tested.

Here's some information on how to perform a charging system voltage drop test.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

The DOHC motor is also bad about trapping air inside the coolant jacket. There are special procedures needed to remove all of the air trapped inside.