Overheating, replacing thermostat question
 

I have 2005 Civic EX. A few weeks ago the temperature gauge was all the way up. I also tested the heater at that time, and noticed that hot air would not blow when I was at a stop.

I picked up some coolant from Honda, and topped up and burped the radiator and reservoir (which was empty). It's been running fine since then, except yesterday the temperature gauge was up again. I opened up the hood and noticed coolant spilled about (underneath the reservoir, along the fan, etc). The reservoir was completely full to the rim. So it looks like coolant is not getting recirculated back in, which makes me think it's the thermostat.

I read through the sticky on overheating (https://www.civicforums.com/forums/3...reference.html), and it seems that the thermostat is best place to start.

What does everyone else think?

I also found a write up on replacing the thermostat, (https://www.civicforums.com/forums/3...hermostat.html) and it doesn't seem difficult. I've done this before on one of my other cars, so I'm pretty familiar with that area.

What brand does everyone use on thermostats? I've got most auto part chains around here, (Napa, O'Reilly, Autozone, Advanced auto parts).

Hopefully this does the trick, rather not have to drop the car off for a head gasket replacement!

Thanks

Re: Overheating, replacing thermostat quesiton
 

Any thermostat should do, advance and o'reillys will be bout the same price, oem is slightly higher but not always a bad option, esp for the head gasket

Re: Overheating, replacing thermostat quesiton
 

stick with oem thermostat, there is no comparison to aftermarket junk and many times the aftermarket will not work out of the box or will not open as much and cause the engine to run hotter than it should.

Re: Overheating, replacing thermostat quesiton
 

Thanks, I'll grab an oem, new gasket, and probably some more coolant. Crossing fingers that this will fix the issue!

Re: Overheating, replacing thermostat quesiton
 

I have exactly the same problem with my 2001 civic lx. I replaced the thermostat and it worked fine for a few days. I also replaced the radiator cap. (I bought the thermostat and the radiator cap from the Honda dealership) However, after a few days, the reservoir's coolant level is almost full. (to a point where it would overflow again). I then changed the timing belt and water pump and therefore, the mechanic put new coolant again and he said he bled out the radiator really good. After a day or two, the coolant level on the reservoir was rising again and in fact, the other day I had to remove the excess coolant from the reservoir and top off the radiator again. However, after driving the car for about 80 miles, the coolant level on the reservoir is almost at the reservoir cap so I decided not to drive the car until the problem gets resolved. There are no other signs like white smoke or engine misfire but I noticed that when the coolant level on the reservoir rises, my heater would not work but when I top off the radiator and set the coolant level on the reservoir between the min and max level, my heater would work. I put all these details because my case is almost similar to the one who started this thread. Is this a HEAD GASKET problem? I therefore leave my/our case to the experts in this forum to give their opinions. Thanks everyone.:)

Re: Overheating, replacing thermostat question
 

reservoir should be at max when cold and a few inches higher when the engine is hot. if its reaching the top, theres a problem and most likely headgasket. you can pick up a test kit from the auto store to check for combustion gas in the coolant.

Re: Overheating, replacing thermostat question
 

My issue seems as though if i drive about 80+ mi in the city only, after having filled up coolant in the radiator cap &/or reservoir before starting out in the day that the coolant in the reservoir has lost barely any coolant, but boy you wait half an hour to open up the radiator cap & it needs more coolant!!!!!..its all burnt up!!!!!!..You find this out only when your car is absolutely posiitvely not wanting to go any further when accelerating however, it makes that racy noise before it even wants to move. At this time, my foot is on the gas and i park on the side just to see if i can open up the hood and let it chill out.
Try & open it up lets say 15 mins later when radiator cap is still little hot, the coolant in the reservoir has emptied halfway and water sprinkles/moves everywhere around the fans/engine/ and you can watch the top of radiator cap all dry begging for more water/coolant. fill it in, let it cool for another 15-20 mins & try moving the car by putting it in drive & it will not want to pick up, also if its a slope/hill the car just dont wanna go anywhere but keep making racing noises when foot on pedal but not exactly move much. It would not let me move forward with the car (my car starts but put in first gear and it will have a very hard time moving forward). I have tried driving after 1 hour ,3 hours and no change. The car just wont move when put in "D" transmission.

Fast forward 24+ hours and let the car cool down(no driving whatsoever) & it runs just fine. I had to have my car towed from the street just becoz i could not wait 2+ hours & try moving it & it wont wanna move?
What do you think guys is happening here?
Its a 2003 Honda Civic Ex 4dr

not good

Re: Overheating, replacing thermostat question
 

My 2005 EX pushing coolant out overflow too. Did everything hoping it wasnt HG. Tested for CO2 in radiator and it was positive. Blown HG! Head was warped. New TB, water pump, HG, auxillary belts, head machined and pressure tested, valve cover gasket, oil and filter, new coolant, and $800. Civic running like new. Finally!

Re: Overheating, replacing thermostat question
 

r u responding to my issue gouncheels1. My 2005 EX pushing coolant out overflow too.
overflow from reservoir or radiator cap!!!!..or it doesnt matter. overflow means overflow
Co2 test done for radiator? how u do that?
it does appear HG per your testing isnt it? maybe this CO2 test will confirm it.

Re: Overheating, replacing thermostat question
 

very strange how the radiator can be empty but not the overflow. the whole purpose of the overflow tank is for the radiator to have extra coolant if needed. it should suck everything in if the coolant starts to burn. unless there are problems with the cooling system pressure like bad cap.

Re: Overheating, replacing thermostat question
 

so gearbox new radiator cap /thermostat will do the trick!!!!!!!..

Re: Overheating, replacing thermostat question
 

there are too many reasons to say for sure. but its always better to start small and work up to the expensive repairs.

Re: Overheating, replacing thermostat question
 

yes it was pushing coolant out the overflow. My mechanic tested for CO2 (exhaust gas) He charged like $25 to test it. The self test kit was more than that

Re: Overheating, replacing thermostat question
 

UPDATE:
after rest of like 48 hrs i tried starting my car and take it for a spin. It appears the car is still not exactly running smoothly. when you try giving gas it appears as though you are parked in P and trying to give gas. It just wont take off. & will make sounds like its racing the car. Keep pushing it a bit and it may actually pick up and move.

Re: Overheating, replacing thermostat question
 

What symptoms does it APPEAR TO BE? TRANSMISSION, HG. FUEL FILTER CLOGGED.

Re: Overheating, replacing thermostat question
 

Very informative thread.