Chrysler Repair: vehicle not heating up, engine thermostat, coolant level

Question
I have a 2001 town and country. Since winter has begun, according to temperature guage the motor does not heat up (very very little), since the motor apparently is not heating up the heater is not blowing warm air. If the heater is turned off for a few minutes then it will blow warm air until the water circulates then it is cold again?

Answer
Hi Steve,
At first evaluation what you describe appears to me to be a failure of the engine thermostat in the "open" position which is causing the flow of coolant through the engine and radiator to be as too great a rate to sustain the normal operating temperature which is in the range of 220F. Fortunately this is a very simple repair as auto repairs go. You would need to drain of several quarts of coolant from the radiator drain plug, collecting it so as to reuse in a clean pan. That lower the coolant level below the housing that hold the thermostat which you then unbolt and remove the old thermostat. You clean the interfaces of the housing to the engine, install the new thermostat in exactly same configuration you found the old one to be in (note this upon first opening), apply a new gasket, and replace the housing and tighten the bolts. Then refill the cooling system with the saved coolant.
I can give you details about the location of the housing and the tension to which the housing screws should be tightened. I can't think of another reason for running too cool such that the gauge reads low and the heating in the van is not working. It might be something esoteric such as the radiator fan coming on too early due to defective temperature sensor, so check to be sure that the fan is indeed not running all the time.
Let me know the engine if you want to try this yourself.
Roland
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