Just recently, from coming home last week from school during the night (I have football practice) I had noticed that my Temp Gauge reached middle, which was odd since it was at night and even at daytime it rarely got to middle (those hot cali days) so I turned on the heat, and thought not much of it.. I watched the temp gauge go down and it was back to normal. Now, just the other night, I had come home from downtown, and I had noticed when I was going uphill my gauge went to 3/4 to the H, I figured (wtf?!) and turned the heat on fast, didn't even do anything.. I looked for somewhere to pull over, but there was none, so I rode it out untill I found a stop sign, came to a stop and the temp went down slightly, so I kept on going and accelerating.. It went down slowly, slowly, hit middle, and when I finally got to my house it was still at middle, and I let it idle in my driveway, it dropped down all the way back to normal temp.. WTF? Previous to this (the day before yesterday) My overflow was nothing, completely nothing, so I refilled it. Is this signs of a bad hg?

Engine and Mods:
B18a1
Drag Gen 3 Kit (Evo Wastegate instead of Marks II)
ACT High Puck Clutch (Which is now slipping)
PWR Civic Half Radiator
12" Pusher fan, Wired Constantly on
No Thermostat

Symptoms:
Overflow, Empty
When car reaches 3/4 H It doesn't get sluggish or sputter
When the car sits back in the driveway, you can't hear it 'burping' into the overflow, or sucking any up.
No CEL besides the occasional O2 Sensor Code from excessively running rich from the FMU in cold weather.

 

Bump

 

sounds like you have air pockets in your cooling system... a trick mystep dad taught me was to take off the radiator cap, start the car and let it warm up...the water will start flowing (not overflowing though) and the air pockets will release through the top where the cap normally sits...it burps itself, but make sure you keep adding coolant (50/50 mix). it should start overflowing when its all burped out. even in hot *** tempratures, it should not get into the middle of the temp gauge...Ive driven in stop and go traffic (100 degrees F, with 100% humidity) and uphill, and it never got close to half way in my teg. You might want to also change your thermostat...it might be getting ready to go. I would get a mugen/spoon one. theyre not expensive and have a lower open temprature.

 

Thanks for the reply, but I run without a thermostat. I'll try the burping technique. any other suggestions?

 

Bump, could it possibly be temp sensor? Same symptoms happen.

 

Fracturing Head Gasket is what it was ruled out to.