so this is still plaguing me.....i replaced the relay, the radiator HAS been working since i replaced it, but every other time (or so) when i start my car, my turbo timer starts counting up ridiuclously high like it was before i replaced the relay, and when i turn my car off after driving for a few minutes my lower radiator hose is cold. Does htis prove its a thermostat stuck closed? Or at least, a thermostat with something wrong that every now and then it will work, and then the rest of the time its stuck shut?

 

So, at this point, you have recently replaced the entire radiator and the radiator fan relay? Is the fan now turning ON when the engine is hot? If so, I'd recommend that you replace the thermostat and then bleed the cooling system of possible trapped air.

 

yes, radiator, fans, hoses and relay have all been replaced within the last couple months. Sometimes the lower rad hose is hot, and this is during one of the times when my rad fan is working, and my turbo timer doesn't count sky high every time i touch the gas. The other times, my rad fan doesn't turn on and my lower hose is completely cool, leading me to believe i have a sticky/unreliable thermostat. Agreed?

 

Yeah, clearly something is blocking coolant flow through the radiator. An obvious culprit is the thermostat, but trapped air in the system is another possibility. Given that the fan sometimes doesn't run, you might first try bleeding the cooling system first and, if that doesn't work, then replace the thermostat.

 

sounds good. thanks again Ron

 

thermostat replaced, radiator is perfect but draining my coolant wasn't easy, i spilled a **** load from behind the theromstat when i pulled it out, oh well, all is well.

 

sooooo my lower radiator hose is completely cold, top hose is hot, my radiator cap wasn't even hot though after a 25 minute drive and my coolant level was full. What would this mean? Remember, thermostat, relay, hoses, ran, and radiator all replaced in the last few months. It was working fine yesterday, but it's still iffy, and on top of this my turbo timer was counting to the sky again on this drive/day. Water pump?

 

How did you bleed the system?

 

bleeder plug on bottom of radiator

 

That's the radiator drain valve not a bleeder plug. 6th generation Civics don't have a bleeder bolt. Turn the heat lever/dial on the dash to MAX heat, and then follow the instructions below precisely. Mk378 also recommends that you park the car on an incline with the front end higher than the rear during this procedure. This procedure may take 30 minutes or longer to complete. Hope for a big burp.