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Discussion Starter · #1 ·
I thought it was a bad thermostat so I changed it out for a new one. The car still over heat. I am for sure the thermostat is not opening. I cooked it in water and it does open up. Did this to two new thermostat.

Could this be a bad waterpump? causing the thermostat not to open?
If the waterpump does not work, does it block the water from going to the thermostat?

HELP!!!!!
 

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i doubt its the water pump but you should be able to tell if its working by reving the motor with the rad cap off if the coolant looks like its moving then the water pump is probably ok, are the fans coming on? was anything done to the car before it started overheating?
 

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Do you have a temp gauge hooked up? Is this your reason for overheating or is there steam coming out of the hood? My fan doesn't come on until about 190 degrees. The thermostat won't open until it hits a certain temp as well.

What radiator are you using? It could be clogged. You may want to have it tested for flow.
 

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Discussion Starter · #4 ·
drhonda said:
Do you have a temp gauge hooked up? Is this your reason for overheating or is there steam coming out of the hood?
What radiator are you using? It could be clogged. You may want to have it tested for flow.
The radiator does steam up all kinds because of test water I pour on it. If water steams up when I pour it on the side of the radiator it means your coolant is above 190 degree.

I just got a new radiator (fluidyne civic), so it's not the radiator. stock temp gauge hooked up. My ex new radiator did not work too.

Fan works fine. But it doesn't turn on until the lower radiator hose gets hot because the thermostat is not opening. more on the buttom.

Here's what I did.
1. start the car, radiator cap off.
2. heater on full blast.
3. put more coolant in as it drops.
4. as the engine heats up, so does the coolant.
5. problem starts here. The top hose gets hotter and hotter every minute.
6. at this point the hot coolant from the top hose heats up the coolant in the radiator. Buttom hose still cold.
7. radiator gets hotter and hotter as top hose heats up more.
8. after a while buttom hose gets warm and temp gauge is now a little past half way. fan wont turn on because thermo is not opening.
9. buttom hose gets hot because of heat transfer from top hose being hot not because of the thermostat opening.
10. fans comes on but not enough to kill the over heating. Then I have to turn on the heater so it cools down. When I turn the heater off it will over heat again.

HELP ME>
 

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Discussion Starter · #6 ·
K20DC2R said:
where is the fan switch located? should be on the upper hose......
What upper? Someone told me to put it on the buttom. Only the temp sensor needs to be on top right?

but the problem is not the fan it's the thermostat not opening for some strange reason. Even if the fan stays on the car stills over heat because the coolant can only go out and in from the top hose only.
 

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I don't understand why the thermostat isn't opening because heat causes that to open and you said you put it in hot water and it opened. SO it does work. Now, for that to not open means that hot water isn't being circulated to there. Do you have your heater hoses hooked up properly? The outlet which is directly on the motor should go to the switch (black thing with wire hooked up to it) and then the one on the firewall should go to the black line that runs next to the motor which is to the right of the one on the motor if standing in front of the car looking down.

I don't think thats it either tho, check it, I think the water isn't being circulated which would mean there there is some kind of blockage in one of the lines.
 

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you neeed to have a coolant line to the top "thin" nipple on the thermostat. If you do have coolant going in there, i can suggest running without a spring, as I did this on my k24a2 for a week before finding the fitting i needed.

Good luck! :up:
 

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is this engine in an rsx? looking though some of your old posts, it seemed like this was a swapped motor. I agree with the above post make sure the fans are spinning the correct way and make sure the shroud is close to the radiator so the fan is actually drawing air through the radiator and not pulling it in from the sides. If you bottom hose is getting hot I'd say the thermostat is fine. You could try putting a large fan in front of the car pointed at the radiator to see if it helps, if it does you need some better fans.
 

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you have air bubbles in your coolant system. run the car with the cap off and with the relief valves off as well. also squeeze your coolant hoses while its running.... that should get rid of the bubbles.
 

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Put a Head Gasket in that thing!
and check for any air bubbles
if you have access to a lift lift the front of the car some and run it also while it runs squeeze the upper hose a few times, sometimes that helps to move a stuck air pocket out of a bad spot.
 

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What type of fan are you using? I have installed some after market fans on Honda radiators and some of them just dont cut it. I had the same problem on a customers car, checked everything in the cooling system and it turned out to be his fan. Installed a stock oem fan and everything was good to go. Also check your radiator and make sure the vents are not caked up with dirt or bugs. You could also check the thermo switch and make sure its working fine.
 

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After driving around this week in the K24 EG, it turns out the head temp sensor is the one that is getting too hot. The temp was at 200 or so after idleing for a couple of minutes in traffic. After moving for 2-3 minutes the MIL goes out and all is well. So it must be the Del Sol B16 radiator and the aftermarket fan just aren't shedding enough BTU's to keep the water temp down.

After looking at the fan, I realize that it doesn't cover about 20-25% of the radiator, so that area has been effectively lost in in terms of cooling capability. I removed the stock shroud/fan assembly due to fitment issues with the air intake and overflow bottle but will have to take another look to see what I need to do.

UPDATE: Replaced the slim fan with the OEM fan and the problem is solved. Idled for 15 minutes in 100+ temps and no check engine light. Been driving all week with it no problems...
 

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typer0186 said:
I thought it was a bad thermostat so I changed it out for a new one. The car still over heat. I am for sure the thermostat is not opening. I cooked it in water and it does open up. Did this to two new thermostat.

Could this be a bad waterpump? causing the thermostat not to open?
If the waterpump does not work, does it block the water from going to the thermostat?

HELP!!!!!

what was your problem I am having the same problem.
 
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