I NEED HELP MY CAR IS OVERHEATING WHEN THE HEAT IS ON

[masrihadi]

ok i have a 97 240sx with a ka. if i drive it with the heat off the car drives fine. when its cold out and i put the heat on the temp. starts overheating. help please anyone.

[TDC240sxPunk]

please explain this better, not understanding. Your car overheats when you turn the heater climate controls on?, shouldn't this reverse opposite?check your coolant level, and look at your heater core.

[Craving4Boost]

how come your very first post on NICO is in the ka-t section about overheating? are you boosting? are you sure it overheats when you turn on the heater? sounds a bit odd

[masrihadi]

ok my s14 im not boosting i changed the termostat flushed the fliud. now when i drvie the car with the heat off the car run fine no problems. when it is cold out i bbut the heat on then the my temp starts going up. my over fill is full of fluid. i started driving the car will the heats on and got on it and it just went up. so when i turned the heat off the temp dropped to normal..

i really need help

[240walker]

possibilty could be air locked. did you take the screw out of the goose neck when you filled the rad. up with coolant? not sure why it would only overheat when the heat is on though. also is it blowing out cool air or hot air when you flip the heat on?

[vvaffle]

What setting is the climate control on? As in, front defoger, bottom vents, top vents?

[freebird21207]

Did you ever find out the problem? What was it?

[Chezedik]

You have air in the system, everyone has this problem at first when they change the fluid. The screw on the intake manifold will need to be removed, while cool. Then you add coolant to the radiator until it comes out of that screw hole. Don't be afraid to bounce on the car. Warm it up, drive it even. See if it happens again, if it does, try again. It sometimes takes a few times. That will fix it. It happens any time you have to open the cooling system on the KA, and it's called vapor-lock. If you are not comfortable doing it, most ships have a tool to remove it.

[xTearsFallForeverx]

You have air in the system, everyone has this problem at first when they change the fluid. The screw on the intake manifold will need to be removed, while cool. Then you add coolant to the radiator until it comes out of that screw hole. Don't be afraid to bounce on the car. Warm it up, drive it even. See if it happens again, if it does, try again. It sometimes takes a few times. That will fix it. It happens any time you have to open the cooling system on the KA, and it's called vapor-lock. If you are not comfortable doing it, most ships have a tool to remove it.

he's right. you have vapor lock. when you change something like the thermostat and dont open the bolt on the intake and fill the radiator... it doesnt fill the whole system because of extra air. when you turn on your heater it allows coolant to run into your heater core causing the rest of your system to be low on coolant. thats why it only happens when you turn on the heat.

[cbishop]

Is it possible that you have a electrical problem. Maybe its a short in the system somewhere due to electronic guages and not mechanical.

[alienwareboy51]

are u re circularing air or is it fresh from outside sometimes recirculating air will over heat the internals other wise its deff an airlock

[Chaotic_Warlord]

You have air in the system, everyone has this problem at first when they change the fluid. The screw on the intake manifold will need to be removed, while cool. Then you add coolant to the radiator until it comes out of that screw hole. Don't be afraid to bounce on the car. Warm it up, drive it even. See if it happens again, if it does, try again. It sometimes takes a few times. That will fix it. It happens any time you have to open the cooling system on the KA, and it's called vapor-lock. If you are not comfortable doing it, most ships have a tool to remove it.

Where is this screw? picture of it would be great, I just posted a question somewhat similar to this. is there more than 1 air bleed screw (ie one on intake and one on radiator?) Im not accustomed to working on the KA and the FSM doesnt explain much of anything unless your doing some serious work and know what you're doing (in other words very limited description and even less pictures).

[240walker]

follow your upper radiator hose from the radiator towards the engine. once you come to the end of the hose on the engine end you will look about 2 inches past the hose and you will see a screw head with some japanese writing just before it that says "do not open when hot". i think it is a 10 mm socket that you will need to fit the screw head. take the screw out, fill up with engine coolant until the coolant runs out of the screw head. put the screw head back in cap off the rad and you are finished. hope this helps.