Have a 98 Civic EX; 162,000 miles; Last November at 150,000 did a flush
and fill after acquiring the car..At that time made sure that antifreeze
in overflow bottle was at MAX mark and radaitor was completely topped
off; watched it for a couple weeks; no change in fluid levels...no
symptons of overheating

1 week ago I had to add approx 1 quart of antifreeze (using dexcool) to
the radiator; antifreeze in overflow bottol was at MAX level..Temp gauge
stayed at 9 O' clock position all week after adding antifreeze..

Today watched the temp needle go from 9 O'clock position to close to the
red mark ..A/C was on at the time; and was idleing in traffic..At
highway speeds the temp needle is at a 9 O'clock position rock solid..
Radiator fan is on; condensor fan was cycling off and on every 18
seconds.. No visible signs of leakage and do not see evidence of
antifreeze in the oil..Added another quart of antifreeze..Might have
headgasket going bad..

Both times the fluid in the overflow bottle was still at MAX level..even
though I needed to add 1 quart to the radiator..

Question's, isn't the radiator supppose to draw coolant from the
overflow bottle should the antifreeze level in the radiator drop??

Does this sound most probably like headgasket going bad ??

Thanks,

Rich