Car will make when running even if heater core is not burned out.
yes.
No
No it wont. The heater core is just a small radiator inside the cabin that when the fan is turned on heats the air. A bad heater core will cause you to have no heat inside or will leak coolant on the carpet.
There are several things that could be going on. The most common thing that would make your car smell like gas when the heater is on would be a bad heater core.
You probibly have a bad heater core.
Bad or clogged heater core. Backflush it.
try changing out the heater core or the therma stat may be bad
the heater core, heater core hoses or heater control valve is leaking
coolant leak inside car underdash on pass. side
Not necessarily. It depends on what you mean by a bad heater core. The core will either be leaking or stopped up. If it is leaking, then it can cause the engine to overheat and the only fix is to replace it. A clogged or plugged heater core can sometimes be fixed by flushing it. You can also temporarily bypass the heater core until you can get it fixed. Just connect the inlet & outlet heater hoses together.
How to replace heater core in a 97 Lincoln Town Car