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Let the engine overheat will normally blow the head gasket.
yes it OK if she wants to blow her brother and he wants it + its not illegal
If you allow the engine to overheat severally, yes.
Not necessarily. It can blow because the circuit was overloaded and pulling too much current. That would cause the fuse to overheat and blow.
no it doesnt blow up
Engine cooling system and passenger compartment cooling system are two separate entities. A failure in one is unlikely to affect the other. Start with checking the thermostat, then you might want to have your radiator flushed.
If you leave on for days it might overheat and not work. But it won't blow up
its purpose is if the engine was to extremely overheat it would blow out saving your block from cracking
the heating coil may have gone out. when this happens a funny smell will also come from the vents.
Your coolant level is low.
She's nervous . She loves you as her partner and her childrens father .She's confused and doesnt want to blow things if that didnt already happen . She wants you to be happy and shes just depressed and doesnt want to put any stress on you.
Check coolant level, and radiator fan operation.