what do you mean by " engine oil temp gauge won't shift"
where is it that you are reading the oil temperature from?
you mean the outside temperature display?
so the engine temp guage does not get warm, and then you don't have any heat in the car?
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this can be caused by a failed temperature sensor (or problem with its connection/wiring) or by an actual cooling system problem that is preventing the engine from actually getting warm, which would most commonly be a thermostat that is stuck open.