Ok, so the motor is a d16z6 with 102k miles on it. When i bought the car I was told it just needed a new thermostat. The car would get hot (about 3/4 the way up) then would drop back down as if the thermostat has opened, so i figure easy fix. Yesterday I go to put the new one in and find out it didnt have one at all.. This confuses me because the temp would get hot at times, then drop back down with no thermostat.. Wouldnt it always be cold? But any way now with the new thermostat in the heat stays at a little less than 3/4 the way up.. Is this safe? Some one help me out lol
Thanks

 

If the radiator is just as old, it may need to be replaced unless you can find someone that can "rod" it (clear the passages through the radiator with a rod). Don't ask me about "rodding" it, I used to know someone that did it instead of replacing the radiator. Other than that, a coolant system flush may help unless the radiator is too small for the D16Z6 and it's summertime. Running the heater will help cool it, but that's a temporary measure.

 

I wouldnt keep running it if the temp is 3/4's of the way up all the time. Is the fan activating?

 

Thanks for the info guys Yea I was thinking of trying a new radiator. The fan doesnt activate, but I also had a civic with a d16z6 with no fan and the temp never went past 1/4 of the way. Btw the bottom radiator hose (one that connects to the thermostat) seems pretty cold. Thanks again for the help. I'm going to see if I can get the fan to work.