i dont know how true this is..maybe others can give some input on this.i was told that when you over heat your thermostat to REDLINE temp areas it ruines the spring on the thermostat...in a sense almost heat treating the spring and making it prone to stick CLOSED.creating a circulation issue that will take your cullant to extreme temps,then ping...the sping unsticks..and everything is normal untell next time it sticks again.obviously bad for the mechanics of the block and head..again,an old mechanic told me this...not sure how true it is.kind of makes sense to me.

such a cheap part is worth replacing again rather then screw your new rebuild up borther.good luck

 

nicenot sure how true this is...maybe some of you out here can give some input on it..i was told if you heat up your thermostat to REDLINE TEMPs,it ruins your thermostat by heating the spring on the thermostat to a point of almost heat treating it,causing it to stick,therefore,not opening,causing the motor to serge in heat,then..ping,spring opens(if your lucky)and it cools suddenly,and acts normal.untell the next time.

better to replace an inexpensive part again,rather then burn your new rebuild.
nice double post...sorry guys...dumber then dumb

 

The thermostat has been replaced but still no luck. It still overheats only when I drove it home, I lost the plastic cap to the coolant reservoir tank as the pressure built up so much it blew it off and of course sprayed coolant all over the engine! I'm at a lost. Everything every forum has suggested I try/check/replace I've done. RIP Honda Civic...

 

Have you tested for head gasket leakage? The basic test is to get the system as full as you can. Then start the engine (cold) with the radiator cap off and rev it. If bubbles continually come out, the head gasket is leaking.

 

For the record, turning the A/C on makes your engine warmer. If you want to cool your engine, turn your heat all the way up onto window defrost without the A/C on. In regards to your overheating issue, you've pretty much covered every single base I can think of... unless the new machined parts messed with your engine?

Sorry I can't offer a whole lot more, I just wanted to throw in my 2 cents about the A/C.