So about 2 weeks ago, my civic starting blowing cold heat sometimes while driving and sometimes it would blow hot, well shortly after, the engine temp gauge started rising and i immediately shut it off, turned out I needed a thermostat. I install a new thermostat, add coolant and let it idle with the cap off for at least 20min making sure I get no air in the coolant system, eventually, everything was good and the car started blowing hot air again. I drove it the next day for about 2 hrs and the car started blowing cold air and engine temp started rising AGAIN. , I then did the same thing as best as I could, it took 1/2 gallon of coolant, kept trying to bleed the system to avoid an air pocket and everything was back to good. I take it to the shop and theres really nothing wrong with it. Im loosing coolant somewhere, its not leaking externally and the head gasket was changed like 2 yrs ago and its not leaking internally since theres no white smoke and the oil is clean, no signs of coolant. any ideas??

 

what are the (2) skinny pipes on the ends of the bottom of the radiator that are pointed upwards

 

Water Pump?

 

the water pump was also replaced tho at the time of the timing belt, how would I be able to check the water pump on this car?usually you can hear them since there are loud bc of the bearing seizing up, im not hearing anything unusual

 

there are 2 small pipes on the bottom of the radiator pointing upwards, what are those

 

when the cars running try to squeeze the main coolant hoses to and from the radiator and see if they have pressure, just dont burn yourself

 

yup, did that already, it sucks in a little when i do it so I add a bit more

 

 

those are for auto matic transmissions. it cools the trans. fluid.

 

hmm, why do I have it, i dont have an auto trans, could this have anything to do with it?

 

I had some problems, too... well blowing cold air sounds like you do have trapped air...
But on the other hand, is your cooling fan kicking on?
Could be that your rad may be clogged...

 

they make these in mass quanities with them all built in.
wont be your problem for sure.

 

You need a head gasket its very common on those models.