tl;dr: The cooling system on this car blows and it's been plaguing my car for the past 3 years. A head gasket leak is my guess.

I first noticed the problem with my car about 3 years ago when I saw my engine temperature gauge becoming unstable quite a few times, usually upon slowing down after a period of interstate driving. When the first mechanic I took it to couldn't replicate my problem (let alone find the cause at all) I assumed it was a sensor malfunction of some sort and thought little of it from then on, up until that was definitely ruled out when my engine destroyed itself and left me stranded in Georgia, little more than an hour from my destination. I had to pay $2,000 to have another engine installed.

...Aaaaaaaaand it STILL wasn't fixed. Two years after that nightmare and it's still been having engine fevers with my new engine. Only recently did I notice that there was some excessive coolant loss going on (fast enough to render unsafe any driving outside the area code), but no noticeable leak. I've narrowed it down (maybe) to the head gasket, since I can see bubbles coming up in the antifreeze reserve tank after driving. If so, then it's an embarrassment for this vehicle to bear the Honda logo if I've encountered the same defect twice.

I have an antifreeze leak that just occurred about 4 weeks ago. During my daily travel to work, temp of engine all of sudden read was reading H. I placed water in tank to hold me over so I could eventually place 50/50 mix for Honda into car and had garage look at it. They could not tell where leak was after running the engine for 4 hours. They flushed system and refilled with 50/50 and a sealant mix. I just hope it works.

I have not had any big issues since then until yesterday when the Overflow hose to the radiator somehow became disconnected. I am in process of getting a hose clamp to keep it on. Hope that works also.

Car overheated 56 miles into a recent roadtrip I was taking on my way to a vacation. The car had to be towed all the way back home where I replaced the thermostat and fan switch, but it kept overheating. Took it to the local dealership where they diagnosed it as having a leaking headgasket, cracked radiator, and said it needs a new water pump, so we also replaced the timing belt while they had it all torn apart anyway. I just couldn't believe that a Honda Civic would already have a blown headgasket and cracked radiator before the car even gets to 100,000 miles. The total cost for all of this will exceed $1,600.