A good symptom of a thermostat stuck open is that it takes the engine longer than normal to reach operating temperature.
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Just adding to the answer :
It will also show that it is running much cooler on the engine coolant
temperature gauge than it normally does with the engine warmed up
It could cause the check engine light to come on with a code concerning cooling system/thermostat performance.It could cause the check engine light to come on with a code concerning cooling system/thermostat performance.
A defective thermostat can cause the engine to overheat. It can also cause the engine to not reach full operating temperature if the thermostat is stuck open. It is possible this could set the check engine light.
This depends on the vehicle. If the thermostat is stuck open the engine won't get to the proper operating temperature which could trigger the MIL (check engine light).
The thermostat would be the first thing I would check.
check the thermostat and/or water pump. also, the radiator could be plugged.
Check the engine thermostat.
It could be just a loose gas cap!
There could be several things wrong with the system that the thermostat gauge is connected to. You could check to see if the gauge is working correctly. If the gauge works fine, then it could be the housing that the thermostat is mounted to. It could also be a faulty bypass valve near the thermostat which prevents the engine from heating up. Check these places to see what may be wrong with your escort.
The piston or spring on the thermostat could be stuck.
First determine if the engine is really running hot if it is check to see if you are low on water, or could be the thermostat is not opening.The thermostat allows water to enter the engine block after it reaches a certain temp.
There could be several reasons for the check engine light to come on. You can take it to Advance Auto Parts or Autozone and if the check engine light is on they will hook it to their computer and tell you exactly what the problem is for free.
it is low coolant temperature, could be the thermostat could be the sensor for coolant temperature.