Why wont my car get hot?

Technical Topics specific to the 2 dr. coupe body - NOT where you post pics/build specs of your car.
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Why wont my car get hot?

By 93CivicEg
- Wed Jan 18, 2012 1:37 am #290653 Ok so i know its cold out side but...

My car needle wont get off C if i get in and start it and drive.
So my heat wont be blowing hot.

BUT....

If i start it and let it sit and let it run and heat up then it goes up.

Then when its in the middle i drive it and it stays in the middle.

Same thing happens to my buddys ek

btw my fan doesnt come on since i have the fan switch manually
so it wont because the fans cutting on,

there are no leaks i did a leak down test, and it didnt even budge

i also replace the heater core and Both upper n lower hoses and all heater hoses
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By asianrob
- Wed Jan 18, 2012 2:06 am #290662 change your thermostat
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By Ajax1989
- Wed Jan 18, 2012 4:48 am #290708 your your sensor could be bad.. the 1 wire plug under your dizzy.. its a yellow wire

By 93CivicEg
- Wed Jan 18, 2012 5:49 am #290735 the coolant temp sensor? i replaced that, if it was bad it wouldnt go up while it is sitting.

i was thinking of the thermostat also, i will replace that soon
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By 95c1v1c
- Thu Jan 19, 2012 12:00 pm #290973 Thermostat!
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By Classiccarsrule85
- Thu Jan 19, 2012 2:56 pm #290995 this may be unrelated but my friendd had the same issue with his 4dr eg let it sit and it would heat up drive it and blam it would cool right down turns out it was a bad heater wire in the o2 sensor dont ask me how that works but as soon as i put a new o2 in i didnt do anything else it worked like normal again it was weird but sounds exactly like this problem
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By 1ACarlos
- Thu Jan 19, 2012 7:00 pm #291037 Sounds like a thermostat to me

By 93CivicEg
- Sat Jan 21, 2012 1:33 am #291290
Classiccarsrule85 wrote:this may be unrelated but my friendd had the same issue with his 4dr eg let it sit and it would heat up drive it and blam it would cool right down turns out it was a bad heater wire in the o2 sensor dont ask me how that works but as soon as i put a new o2 in i didnt do anything else it worked like normal again it was weird but sounds exactly like this problem


i just replaced my o2 sensor and it did it before the 02 sensor also

i bought a new thermostat yesterday, will be installing it this week
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By Ajax1989
- Sat Jan 21, 2012 3:44 am #291300
93CivicEg wrote:the coolant temp sensor? i replaced that, if it was bad it wouldnt go up while it is sitting.

i was thinking of the thermostat also, i will replace that soon


No not the ect but the 1 wire running under your dizzy
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By Apexracing
- Sat Jan 21, 2012 3:03 pm #291330
bigJOE671 wrote:I have the same problem...If you change your thermostat please put up a DIY. I have no idea on how to do it.



Follow the lower radiator hose as it goes back towards the firewall. Notice it connects to the head just behind the distributer. This is the thermostat housing. Make sure the engine is cold and remove the clamp on the hose. Twisting slightly as you pull remove the hose from the housing(note you will lose some coolant, so place a bucket under your car). Next there are two bolts/screws on the face of the thermostat housing. Remove these and set the cover aside. next pull out your thermostat make note of the direction it was removed and insert the new one in the same manner. making sure the gasket in correctly seated. You might want to purchase a new housing gasket if one is required. reassemble the housing and attach the hose and clamp. Next open up the radiator and add the coolant you lost, use a 50/50 mix or dilute standard antifreeze using the proper amount of water. Add to the radiator until its full leaving the cap off. try to squeeze the lower radiator hose until most of the bubbles come out of the top of the radiator. Then top it off with coolant and start the car, again with the cap off the radiator. turn the heat all the way on, and watch the radiator. as the car begins to heat up and the coolant begins to circulate air bubbles will work there way out the top. Notice the coolant level will drop as air escapes. Keep it topped off every time it drops. when the engine reaches normal operating temp and you have great heat, top off the radiator again and place the cap on. Keep checking the coolant levels over the next few days(always on a cold engine) if the level stays the same then you got all the air out.

Enjoy :)
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By bigJOE671
- Sat Jan 21, 2012 3:20 pm #291334
Apexracing wrote:
bigJOE671 wrote:I have the same problem...If you change your thermostat please put up a DIY. I have no idea on how to do it.



Follow the lower radiator hose as it goes back towards the firewall. Notice it connects to the head just behind the distributer. This is the thermostat housing. Make sure the engine is cold and remove the clamp on the hose. Twisting slightly as you pull remove the hose from the housing(note you will lose some coolant, so place a bucket under your car). Next there are two bolts/screws on the face of the thermostat housing. Remove these and set the cover aside. next pull out your thermostat make note of the direction it was removed and insert the new one in the same manner. making sure the gasket in correctly seated. You might want to purchase a new housing gasket if one is required. reassemble the housing and attach the hose and clamp. Next open up the radiator and add the coolant you lost, use a 50/50 mix or dilute standard antifreeze using the proper amount of water. Add to the radiator until its full leaving the cap off. try to squeeze the lower radiator hose until most of the bubbles come out of the top of the radiator. Then top it off with coolant and start the car, again with the cap off the radiator. turn the heat all the way on, and watch the radiator. as the car begins to heat up and the coolant begins to circulate air bubbles will work there way out the top. Notice the coolant level will drop as air escapes. Keep it topped off every time it drops. when the engine reaches normal operating temp and you have great heat, top off the radiator again and place the cap on. Keep checking the coolant levels over the next few days(always on a cold engine) if the level stays the same then you got all the air out.

Enjoy :)


Thank YOU!

By 93CivicEg
- Sun Jan 29, 2012 2:47 am #292440 well i fixed the thermostat,

come to find out there wasnt even one in there :)

now i got heat, thanks guys
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By Apexracing
- Sun Jan 29, 2012 2:53 am #292441
93CivicEg wrote:well i fixed the thermostat,

come to find out there wasnt even one in there :)

now i got heat, thanks guys



Awesome!
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