Heater Core
Thread Starter
Pole Position
Joined: Jul 2007
Posts: 201
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From: OK
Heater Core
My heat stopped working recently and I need to figure out the problem. Can anybody instruct me on how to get to the heater core in a '98 SC?
Also, I've never had this issue before, so could anyone give me some potential catalysts for this problem?
Also, I've never had this issue before, so could anyone give me some potential catalysts for this problem?
It could be something stuck in your cooling system.If so the coolant does not travel through heater core therefore you have no heat.
If your car overheats then your pipes are cloged.
If your car doesnt overheat,then its your heater valve.Try to take it off and inspect it before you even think of trying to change the heater core,which would probably be worst thing you can work on.But the good thing is you can sit and do it vs bending over the engine bay breaking your back.
If your car overheats then your pipes are cloged.
If your car doesnt overheat,then its your heater valve.Try to take it off and inspect it before you even think of trying to change the heater core,which would probably be worst thing you can work on.But the good thing is you can sit and do it vs bending over the engine bay breaking your back.
Lexus Test Driver
Joined: Nov 2007
Posts: 1,021
Likes: 0
From: Palm Harbor ,Fl
Here are the possible issues that could be the heating problem. The heater valve like mentioned before, bad coolant that turned into chunks and blocked the heater core, your thermostat could be open all the time keeping the coolant cool,also your a/c could be at fault. The (blend air door) that blends outside,inside,and heated air could be broken. If you listen closely and change the a/c setting listen for the movement of the door. If you want to access the (squirrel cage) (A/C box) you have to take the glove box off and remove the lower cover. Then you can get some access to it and then you would see where you could put your a/c filter. If you want to remove the whole cage you would have to remove the dash. I wouldn't go to those measures though once you cover the small things first. 
Thread Starter
Pole Position
Joined: Jul 2007
Posts: 201
Likes: 0
From: OK
Thanks for the help guys, sorry I haven't replied, I was out of town the past week.
So I turned the cc **** from hot to cold and back, and I heard the motor running to move the door, but I couldn't tell if the door moved or not. No clicking sound or anything, and the air temp didn't change. I get plenty of airflow into the cabin, and my engine temp is normal, so I assume my coolant is circulating fine (although whether it's making it through the heater coil I don't know).
Is there a way to clean out the system without taking my dash apart? I heard somewhere about a spray solvent that can break lose grime in the vents, but I don't know anyone who's used it.
Also, could anyone post a picture of the location of the heater valve? I'm not exactly sure what I'm looking for.
--EDIT--
Ok, so I somehow got heat tonight. I suspect it does have something to do with the valve, although I suppose there could be residue in the coils. I got it to work by turning the CC **** from hot to cold and back a number of times in succession, waiting for the motor to run each time. I would still like to know how if I can clean it all out or at least the valve part, since winter is fast approaching.
So I turned the cc **** from hot to cold and back, and I heard the motor running to move the door, but I couldn't tell if the door moved or not. No clicking sound or anything, and the air temp didn't change. I get plenty of airflow into the cabin, and my engine temp is normal, so I assume my coolant is circulating fine (although whether it's making it through the heater coil I don't know).
Is there a way to clean out the system without taking my dash apart? I heard somewhere about a spray solvent that can break lose grime in the vents, but I don't know anyone who's used it.
Also, could anyone post a picture of the location of the heater valve? I'm not exactly sure what I'm looking for.
--EDIT--
Ok, so I somehow got heat tonight. I suspect it does have something to do with the valve, although I suppose there could be residue in the coils. I got it to work by turning the CC **** from hot to cold and back a number of times in succession, waiting for the motor to run each time. I would still like to know how if I can clean it all out or at least the valve part, since winter is fast approaching.
Last edited by CDY; Oct 23, 2008 at 11:34 PM.
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Driver School Candidate
Joined: Oct 2008
Posts: 5
Likes: 0
From: Utah
I recently fixed my valve, Its mounted on the firewall on the passenger side its not hidden or anything and there should be a heater hose going to the valve that you can see right on top with the other hose going out the bottom thats a little more difficult to see. I had my boyfriend hold the vacuum hoses down to see if the valve would open or close. Nothing happened. So while I save up the 300$ for the new valve because the rubber plungers broken in the valve, I just took some zip ties and strapped them around the valve to hold it open for the time being.
Hope this helps
Hope this helps
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