HELP!!!! Car is over heating after thermostat change

05HondaChic · 05-02-2009

I have a 2005 Honda Civic, I recently replaced the thermostat and now the car is still over heating. We originally thought it could be the water pump but the fans are not kicking on. Could this just be a sensor issue? I am new Honda owner and did not know where else to turn with the issue. If anyone has a suggestions or ways to troubleshoot please let me know. I am lost at this point. Thanks in advance

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gearbox · 05-02-2009

yeah there is a fan sensor near the thermostat housing. not the one on top, thats the engine coolant temp sensor. its the one on the side. it tells the fan when to turn on if the car gets too hot. do both fans turn on when you use the A/C? if not, it may be a fuse or relay or even a broken fan (mechanical problem).

nametakento · 05-04-2009

I had a similar problem. Maybe your Cooling fan switch is broken, i think this happens due to the coolant getting too hot, it burns out the mechanism that makes this switch work. Its on the thermostat housing. I replaced mine today(25 dollars) and my problem is gone. I replaced my engine coolant sensor because it was broken but it didnt fix my problem, so i replaced my switch too, and now my honda is happy. Oh, to make sure its not your fans first, turn on your AC, if your fans work then you know that they are OK. If they dont turn on then maybe their burnt out, i dont think so, however, i have a feeling its the coolant fan switch. Honda's are very sensitive machines.

Let me explain briefly what happened to my car. About 2 months ago, my car bottoms out and the oxygen sensor 2 that is on the catalytic converter breaks. Oh, and my alternator belt fell off, so i had all that replaced and changed but i had this bad hickup problem where my 01 civic wanted to stall out. So i spent about 1100 dollars on miscellaneous parts to single out the problem, WOO HOO GO HONDA DEALERS! Anyway, Just today, I bought a Cooling fan switch, which tell my fans when they should be on to cool down the car, 25 bucks or so. But that solved my hiccup issue. My charging system is messed up right now though, i think something is wrong with my battery.

mr22508 · 05-05-2009

When my car was overheating I replaced the thermostat, and it kept overheating too, well come to find out it was because I was losing coolant due to the fact that I was getting pressure blow by my head gasket causing my fluid to be insufficient. BLOWN HEAD GASKET!!! Sucked but I got it fixed.

d0ughbOy81 · 05-28-2009

sorry for the late input but this just happened to my girls 7th gen it overheated pushing coolant out the overflow bottle so i replaced the thermostat, but it overheated again so i replaced the elect temp sensor. it overheated again. not bad just enff to scare my girl so the last thing left was the fan switch and so far soo good

real easy to do just need a deep 14mm and deep 24mm socket wait till motor is cold and swap them out a lil coolant will come out of the fan switch

mr22508 · 05-28-2009

Quote:

Originally Posted by d0ughbOy81

sorry for the late input but this just happened to my girls 7th gen it overheated pushing coolant out the overflow bottle so i replaced the thermostat, but it overheated again so i replaced the elect temp sensor. it overheated again. not bad just enff to scare my girl so the last thing left was the fan switch and so far soo good

real easy to do just need a deep 14mm and deep 24mm socket wait till motor is cold and swap them out a lil coolant will come out of the fan switch

If it happens again, then its your head gasket. Cause I had all the same symptoms as you.

Schuy · 05-28-2009

Check your fuses first, i had this happen on mine this spring and its happened to a couple of my friends cars and all of them were just blown fuses. If not fuse then look into temp sensor, fan motor, or switch.

fadiriad · 06-04-2009

Even after I changed the fan switch and thermostat it is still over heating. I found out that the fan only work when the temp gauge gos to max, but still even when they go on the gauge dose not go down. what I did is connected the fans to stay on all the time, but it dose not help much. when I turn the heat on to full the temp gos to normal.

what is wrong with my car?

gearbox · 06-05-2009

could be a bad water pump or radiator, not circulating the coolant fast enough to cool it. when you turn the heat on, coolant is routed to the heater core under the dash and some heat blows out the vents which will help cool the antifreeze.

johnhumid · 09-06-2009

yes there is a fan sensor near the thermostat housing.

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mclean987 · 10-15-2009

if i hook both fans up straight can this cause a problem ? and does the Cooling fan switch control the thermostat or if not what controls thermostat and makes it open and close? if water pump is bad does the thermostat hose stay cold when the top radiator hose is hot?

Quote:

Originally Posted by gearbox

could be a bad water pump or radiator, not circulating the coolant fast enough to cool it. when you turn the heat on, coolant is routed to the heater core under the dash and some heat blows out the vents which will help cool the antifreeze.

gearbox · 10-15-2009

thermostat is self controled. there is some wax inside that melts and it opens. just putting the thermostat in hot water by itself will activate it. the fan switch only controls when the fan turns on, based on the coolant temp. its possible to have the bottom hose cold if the water pump is busted. that means coolant is not circulating thru the system properly. the top hose comes from the engine, the bottom is the return hose once the coolant has been cooled by the radiator. you have a new radiator right? otherwise i would say its clogged radiator.

mclean987 · 10-15-2009

thanks yeh brand new radiator and cap and hoses and thermostat ? i looped fan switch so fans stay on and temp guage works fine so i figured ect is good, what else can i do? thinking of changing water pump and boring out thermostat or running without it, all seems to be good now no longer going all the way to hot and overheating coolant isnt boiling but pressure builds up because lower hose is cold and not flowing

Quote:

Originally Posted by gearbox

thermostat is self controled. there is some wax inside that melts and it opens. just putting the thermostat in hot water by itself will activate it. the fan switch only controls when the fan turns on, based on the coolant temp. its possible to have the bottom hose cold if the water pump is busted. that means coolant is not circulating thru the system properly. the top hose comes from the engine, the bottom is the return hose once the coolant has been cooled by the radiator. you have a new radiator right? otherwise i would say its clogged radiator.

gearbox · 10-15-2009

ect sensor you cannot assume is good just because the temp gauge works. that gauge has three settings, cold, warm, and hot. lol. its barely a real gauge to begin with.

mclean987 · 10-16-2009

thanks dude i will change it first thenthen but say it is bad would that make the lower thermostat hose stay cold as if thermostat isnt opening when its a brand new one