If the temp us below 60 deg. Fahrenheit it wont get to operating temp even after 45 min of driving at highway speeds. And if it is above 60 it wont reach it occasionally.. what could it be?
My car has 265000 miles.
My car has a manual transmission.
The most common and most likely cause for the engine to not get to operating temperature is commonly cause by the thermostat stuck in the open position or is broken. The thermostat stuck in the open position will cause the heater to not get hot and the engine to run too cold causing loss of fuel mileage and can even lead to carbon build up and running issues in the engine. Have a mechanic like one from YourMechanic test and replace thermostat.
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