I should have said, "As for engine wear, you are very unlikely to get 50,000 MORE miles from an engine that isn't running at the right temperature. The thermostat wasn't out of the engine for all of its 200,000 miles.
Nothing is going to suddenly fly apart but excessive wear is taking place in the engine. If I can find my other reply I'll paste a copy for you. You aren't going to do sudden damage in the short-term but as a person who beats the last ounce of life out of everything before I discard it, I pay particular attention to anything that can make them last longer. Thermostats don't fail as often as people think. They often remove them in a misguided attempt at solving a problem.
As for overheating, if that were to happen, the Engine Computer will turn the radiator fan on. It doesn't know about the missing thermostat; it just watches the coolant temperature.
Coolant in a wire or its connector comes from leaking through the sensor. That isn't real common but it did follow the wire all the way inside the car on a GM product a few years ago and made puddles on the floor. That's because there were no connectors in between like you normally find at the firewall, and thanks to the rubber weatherpack seals in the sensor's connector, the coolant leaking through it had no place to go except to get forced between the wire and its insulation. In your case, replace the leaking sensor and dry off the coolant on the connector pins. Use a little brake parts cleaner or electrical contact cleaner in a spray can to wash it out. Be sure to check for signs of corrosion or residue that could interfere with it making a good contact.
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Saturday, October 27th, 2012 AT 10:55 PM