My car is overheating


Asked by hailsbrown Aug 30, 2015 at 02:52 PM about the 2012 Kia Optima LX

Question type: Maintenance & Repair

replaced the radiator, the radiator cap, thermostat. Everytime the car heats up the coolant would boil and push the coolant out from the container. We checked the water pump and fans, everything ok...When the car is started, it blows out cool air, and the radiator hose on the right side is really hot. Seems its not curculating....we dont know what else it the problem? The car is 2012 Kia Optima LX

11 Answers


head gasket. how soon after starting it from cold does it blow coolant out of the radiator? take the cap off and top the fluid off and start the car see if it pushes the fluid out right away if so look at head gasket or head being warped. other thing you can do is pull the cap off the radiator and with out running it give it a sniff see if you smell exhaust if not start it let it run for a cupple secounds and then smell it again.

6 people found this helpful.

its cold right as soon as the car is started. what type of fluid? i been using the 50/50 Prestone...i think its the wrong one. it doesnt push the fluid out, takes about 30 minutes to.

1 people found this helpful.

ok the 50/50 is fine but you might want to call a parts house and see if it should be using a dexcool rather then conventional antifreeze. if it takes 30 min for this to happen what I want you to do is fill the radiator up put the cap on it start it and run it till it gets warm check to see if you can feel it if the bottom raddiator hose is getting warm. thinking you might have a thermostat that is bad and not allowing circulation. this would also cause the heater hoses to stay cold

2 people found this helpful.

if it starts getting close to the hot line shut it down see if the hose on the bottom is still cool it should be hot by now and well as hot as the top one.

4 people found this helpful.

if everything dont go the way it should, what would be the problem? If it were the heads, then how does that get placed.?

3 people found this helpful.

if there is no circulation of the coolant, you could have a bad temp sensor and/or a bad water pump. The water pump impeller can be damaged to not create enough flow thru the engine.


sounds like you have air trapped in your heater matrix, remove radiator cap and fill with coolant start engine and run till hot with heater lever in hot position squeeze water hoses that come from bulkhead too engine block, you should see air come out through top of radiator, when all the air has finished switch on heater blower to check heater is hot this should cure your fault

2 people found this helpful.

I have a 2004 Kia sorento ex and we changed all radiator new thermostat. New radiator cap. New radiator bushing new sensors. But still boiling the antifreeze thru the overflow fill box? No water in oil and no engine knock hoses are hot and so. Is radiator. Put half a gallon of antifreeze and it seems to not be going into the radiator what could be my issue?? Anyone? I'm leaning towards water pump more then heads but I'm not sure. I know I'll never buy another Kia ever

4 people found this helpful.

My mechanic replace a crack radiator and thermosta. My car is still overheating the fan is not turning on. Also the engine coolants leaving the reservoir.


Are you guys filling the reservoir past the fill line? That would have caused this problem as well. Usually a bad water pump won't cause the car to overheat. The most common complaint for a water pump is that it isn't putting out hot air. If the oil is creamy then it's a head gasket. If you've replaced the thermostat and it takes 3p mins for this to happen, I bet you the new thermostat was probably bad. The cheapest ones are that for a reason...

2 people found this helpful.


1 people found this helpful.

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