i drilled like 3 small holes on my thermostat to have some constant flow, havent really gotten a chance to try it since the car is not together but it should make it cool down a litle better...

 

ok, if there was air in the cooling lines or in the rad the cel would come on. I am almost positive that the overheating is the headgasket , hint ... check for compression and any leaking liquids such as antifreeze under the distributor, a sure sign of a leaking head gasket. secondly, for a headgasket, use a 92 and up civic sohc vtec head gasket, the metal one. I have an 89 crx si and thats what i am running. buy a new water pump too, they are reasonably cheap, and can save you the hassle down the road.