Rep Power: 0

ive got an 05 civic ex se coupe 1.7 mt vtec that ive had for 1.5 yrs. love it, no problems till now. it started leaking coolant a couple times, not continuously, after i drive it kinda hard. and determined it was coming out of the resivour, which was overfilled almost to the cap. mind you, i havent put any coolant into the thing. i took off the radiator cap to see if the seal was bad, and it let out a huge gasp of air and the level in the res went down to normal after i ran it once, so im assuming air pocket. the next day it started overheating and the coolant level went back up. the next day (yesterday) i tried getting it to overheat again to see if its consistant, nothing happened. i changed the thermostat cause its quick easy and cheap, then i tested the old one and it still worked.

anyone have any ideas? im lost

 
Rep Power: 0

head gasket

 
Rep Power: 233

To elaborate, have the coolant checked for exhaust gases before you rip half the engine bay apart to do the timing belt/water pump.

 
Rep Power: 811

seems to be a common problem with these cars.