i have a 02 civic ex110K, Radiator1 yr old new waterpump and timing belt 1 mo old,All hoses checked for leaks I live in hawaii and my mechanic said no need for a thermostat so i said take it out thus no thermostat. Radiator 50/50 h2o and rad fluid..He has looked it over 3-3 x but it keeps overheating. If in stay under 60mph it goes 1/8 "under middle on gauge.Before i had this problem it was always at 25% or less from cold.I drive 43 miles to work first 12 are 35mph no problem..Then next approx.31 are highway speed limit 55-60.When i go 70 it overheats in seconds. As long as i stay around 55-60 it is ok but if there is a traffic jam or backup it will overheat in minutes. i thus must turn it off when ever i can in the traffic to cool and cars in back do not like that.Can anyone tell me what more i can do to stop the overheating.. I am at my wits end. All hoses are good as is circulation and there are no leaks. My A/C is broken so do not use that and when i run the heater it at times will bring it down maybe 1/8" but very little and dammit it is hot overhere and by the time i get to work i am a sweatball with the heater running for 1 hour..Thank you for any help you can give me as my mechanic cannot think of anything else..I noticed the ECD light comes on once in a while could that be any thing with it..We have no emmission control checks here in hawaii so i dont care to get it replaced if it goes.Thank you again for any help I forgot to add on my way home last night heat gauge was in middle then first time this happened I had pulled into a 7-11 and car was still hot when i went to drive away after car being off for maybe 5 min..Gauge went down almost to very bottom to cold maybe 1/8" from bottom of cold scale.,Stayed there for a few minutes then went back up to hot..I never checked the hotness of radiator when it reads HOT but could there be something wrong with the actual dash heat temp monitor ??? I just cannot think of anything else...PLEASE HELP

 

Whenever the light comes on you should scan the code just to know why.

Removing the thermostat, as you have found, seldom solves anything. The engine will get better gas mileage and last longer if it warms up to design temperature and stays there by the action of the thermostat.

Is the radiator staying full? Check it when cold before each trip. This is in the radiator itself don't just look at the side tank. If you keep losing fluid out of the radiator the head gasket may be leaking. Also if a "stop leak" agent has been used it could have clogged up the radiator.

 

No stopleak.The light is for emmission controls.He checked it and it was low on .we filled it up and noticed that the overflow container is accepting the overflow water but it is not being sucked back into the radiator...What could be or not be doing this?? thus i guess what is happening is the water is being sucked up by the overflow and as there is no cap on overflow it bubbles out and then what is left is not going back into radiator/If it was the headgasket wouldnt there be something else i would hear or feel on acceleration?? as it runs perfect

 

That is typical for a slow leak in the head gasket. You see bubbles in the radiator when you start the engine cold and rev it. This gas will displace the coolant into the bottle and it doesn't come back, leading to overheating. There are no other symptoms of a small leak.

 

This would be the 3rd person in the last two weeks having this issue and the tstat was removed. I doubt there is a relation between the two, just something I have noticed recently.

 

could be an air bubble in the system burp it. could be a bad radiator cap replace it. could be your fans not turning on run it make sure it turns on. also put your dam thermostat back.