Tensa_Zangetsu

Hi, recently i realized that my car's thermostats shoot from midway to all the way up to H when its is stuck in traffic( especially in hot weather). Can anyone explain to me on how to fix this please and wat is the possible outcome if this keeps on happening.

-Thanks

Mr.EM1_EK

check to make sure your fan is working. also try and swap in a new thermostat your old one may be stuck closed

tech8

The consequence of it keep overheating, may be a blown head gasket, or engine need replacing... $$$.

Tensa_Zangetsu

alrite thxs for the tips. btw is it expensive to change new thermostats?

Mr.EM1_EK

no they are like $10 or something like that.

Tensa_Zangetsu

weird thing is that when my car thermostats goes all the way to H, and then i drive for a while, the arrow starts to get lower to about close to midway. is that how it is suppose to be like? btw, if my thermostats was H, how should i handle that situation?

Mr.EM1_EK

because when you drive you have air flow to your radiator, it could also be the temperature switch not letting the fan kick on when it's sopposed too. it's not good driving on h like that, you can blow your head gasket and warp your head or block. you should check it out asap. make sure you have no leaks also

gsxr1k05

ok, first off, not being a dick, just helping with termonology. its not your thermostat that jumps to H. it's your temp guage. as for your overheating problem, take your old thermostat out, and put it in a pot of water, boil the water. the thermostat should pop open at either 180 ferinheit or 190. if not, its bad, and you need a new one along with the gasket. you can get the civic service manual from my sig. to help you with this. as for why the car cools off when you drive, mr.em1_ek was right in his explanation. when you move forward the outside air pushes aginst the radiator cooling the water. i would check to make sure the fan turns on. next time the car over heats, pop the hood and see if the fan is running. if not, then its either the switch, a relay, or the fan itself. the service manual will tell you how to trouble shoot all of this. any questions, just post a reply and we can all help ya.

Tensa_Zangetsu

hey thxs for the well explained resolution gsr but when u said "next time the car over heats, pop the hood and see if the fan is running" does that implied the only time to be ablet o see if the fan works is when it overheats? (not to be an ***, but it is my curosity, b/c im quite new to how the coolant system works.)

Syndacate

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tensa_Zangetsu &raquo;</TD></TR><TR><TD CLASS="quote">hey thxs for the well explained resolution gsr but when u said "next time the car over heats, pop the hood and see if the fan is running" does that implied the only time to be ablet o see if the fan works is when it overheats? (not to be an ***, but it is my curosity, b/c im quite new to how the coolant system works.)</TD></TR></TABLE>

When the car's water temperature gets hot enough (usually at idle), the CTS (coolant temperature sensor) tells the ECU to tell the fan to turn on. The fan blows cool air (even if it's 100 outside, the engine operates at ~190ºF) across the radiator cooling the water.

The reason it's not on while you're driving is because the air is being moved across the radiator as you're moving through it.

So what you do it you pop the hood, start the car, and let it idle. If it gets more than 3/4 of the way to "H" and the big *** fan in back of the radiator hasn't started spinning, your fan isn't kicking on like it should (and that sounds like it's the problem). From there it's usually one of two possibilities,

A) The fan is broken
B) The CTS isn't operating correctly and not picking up the hotter temp of the water and telling the ECU (engine control unit) to tell the fan to turn on.

To tell if the fan is working, simply run a wire from the positive terminal of the battery to one of the fan plugs, then run another wire from the negative terminal to the other pin on the fan plug. If the fan starts spinning, it's most likely your coolant temp sensor (located next to the dizzy, by the rad hose), if it's not spinning, your fan is bad.

Hope that helps .

Tensa_Zangetsu

hey about the fan... when i turn on my a/c the fan is spinning is that the fan u're talking about? if it is then its working but the weird thing is that the other fan dosent work when i turn on the a/c.

Tensa_Zangetsu

does anyone know the thermostats is located at in a 96 civic

tech8

They show it in this thread:

https://honda-tech.com/zerothread?id=1424191

Tensa_Zangetsu

hey i replaced my thermostats today and also wash out all my old coolant and put in new one... but some reason after driving for 15 minutes my temp guage seems to get to H faster than before. can anyone help me and tell me wats the problem plz.

wiZCo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tensa_Zangetsu &raquo;</TD></TR><TR><TD CLASS="quote">hey about the fan... when i turn on my a/c the fan is spinning is that the fan u're talking about? if it is then its working but the weird thing is that the other fan dosent work when i turn on the a/c.</TD></TR></TABLE>

That other fan that doesn't work is the main cooling fan. The fan that comes on with your a/c is the a/c fan.

You need to check your coolant temperature sensor, the fan switch and the relay. A Helms manual will outline these procedures.

So, your fan doesn't work and you need to get it working again.

tech8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tensa_Zangetsu &raquo;</TD></TR><TR><TD CLASS="quote">hey i replaced my thermostats today and also wash out all my old coolant and put in new one... but some reason after driving for 15 minutes my temp guage seems to get to H faster than before. can anyone help me and tell me wats the problem plz.</TD></TR></TABLE>

Did you bleed the air out of the cooling system?

Yeah, you got to fix the radiator fan problem too.

Tensa_Zangetsu

wat does bleeding the air out and how do i get hte fan fix plz. and could the incorrect installation of the thermostats might have cause the problem as well.

watsvtecEK

Take the radiator cap off (when it is cool) and turn the car on and let it idle. Squeeze the top radiator hose and you should see bubbles coming out. let it idle and keep adding coolant because it will need more. if you bleed the coolant system and your fan is working and you still overheat then you should check to see if there is an obstruction in the radiator that slowing the flow of coolant.

Tensa_Zangetsu

HOW DO I FIX MY FAN?

tech8

Look for the Engine Coolant Temperature sensor, which is on the thermostat housing (look in the pictures of the thread linked above), unplug that connector. With a jumper wire, connect the two terminals on the connector. Turn the car on, if the radiator fan works, it means the fuses and relay are okay, and the ECT sensor needs to be replaced.

If the radiator fan doesn't turn on, then it means the radiator fan motor needs to be replaced, or some wires on the radiator fan are messed up.

Syndacate

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tensa_Zangetsu &raquo;</TD></TR><TR><TD CLASS="quote">HOW DO I FIX MY FAN?</TD></TR></TABLE>

You're ******* pathetic.

People are asking you questions to try and help you, and you just get pissed off like a 13 year old bitch.

It's quite simple, if you can't fix it after you read my last post, you don't deserve to fix it - just bring it to a mechanic.

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Very simple - when you look at your engine from the front of your car, the fan on the right is your AC condenser fan, the one on your left is your radiator fan.

Now, run wires from the plug on the fan to the positive and negative terminals on the battery (just some 14 gauge wire taped to each battery terminal is fine). It doesn't matter which goes where on the fan plug, it'll just spin reverse or forwards. If it doesn't move, then your fan motor is broken and you need a new fan. If it spins, that means your fan is operational.

If your fan isn't operational the problem ends there, you need a new fan.

If your fan is operational, you need to look at your coolant temp sensor. It's located on the left side of the block (when looking at the engine from the front of the car) under/next to the distributor. It looks like a little needle-type thing when you pull it out and has a thermometer tip at the end of it.

You were too stupid to include in your OP what motor it was, so I'll just assume it's a Y8 - other Honda/Acura engines will have it in the same general location.



It's part #13 in that diagram. It's a cheap sensor, about 27 bucks.

If the fan works when jumped to the battery, and the CTS sensor has been replaced, your wiring is fucked up. The wiring can be one of two places:
One: The CTS to the ECU - though if this wiring is bad, you will throw a check engine light for your coolant temp sensor.
Two: The ECU to the radiator fan, it might be shorted out someplace.

That's it, that's all there is to it, nothing else can cause this problem. The thermostat does NOT control the radiator fan. All it does is keeps the water in the block stationary so it can be warmed up while the engine is warming up, then when it reaches standard operating temperature (whatever the temp is for the particular thermostat), it opens up and allows the coolant to flow through the radiator and help cool the engine. If there's no air passing over the radiator to cool the coolant, the fan will kick on. Now the fan kicking on is based on NOTHING other than the CTS.

That's EVERYTHING you need to fix your car. Like I said at the beginning of this post, if you follow this to a "T", and still can't figure out what's wrong, take it to a mechanic because you're obviously not smart enough to do it on your own nor do you actually want anybody's help. You just want somebody to tell you the answer without doing jack ****. So follow either one of my posts and fix it, or take it to a mechanic. ****.