Ok guys I just bought a 05 civic 4cyl for driving to work it had new water pump and timing belt first day I drove it it overheated thermostat was bad I replaced it I have drove it 5 more times the temp gauge stays normal but when I get where I’m going steam is coming out from under the hood and the coolant is about a half. Qt low but I don’t see any leaks got me stumped

 

Check for a blown head gasket. Symptoms are lack of heat from HVAC and coolant being purged out of the reservoir. Common issue with these engines. Overheating and mysterious coolant loss common causes - reference - Honda Civic Forum (civicforums.com)

 

I've bought cheapo thermostats before that caused problems so I go to the dealer for them ($$) so I know it's not the thermostat . But do a compression test to be sure , put it in hand tight so that you can get it back out .

 

i replaced thermostat again i drove 90 miles this moring to work didnt over heat but coolant was low filled it back up about 3/4 away home it statrted over heat it was a little warmer outside then normal i pulled over let it cool and added coolant drove the rest of the way home but i noticed the temp gauge fluxuiating cant figure this out

 

You should do the compression test , a bouncing temp. gauge would point to the thermostat but you replaced it , did you get the $8** one from auto zoo ? If you have time start it up , get it warm and watch for any leaks .