I just finished my gsr swap into my civic ex. I started it up and my radiator started smoking. I flushed the coolant for air and felt my radiator and it was hot on both sides my fan doesn't spin. I need to figure this out so i can get driving on it. anyone with similar problems could help me out?

 

Originally Posted by ej888
Exactly my problem and found out it was the coolant temp switch. I would first jump the fan to see if it even works. Next warm up your car and wait for the thermostat to open(you know it has opened when the lower hose is as hot as the top hose) If it opens and your fan doesn't come on within 5-10 sec, it's your coolant temp fan switch.

 

I just tested my fan it works. What's the coolant temp switch? I let my car run and both my lower and upper hose were hot and my fan doesn't come on at all.

 

engine coolant temperature switch location: Follow top radiator hose down to engine. The hose connects to a "thermostat cover". Also on the Thermostat cover is the engine coolant temp switch your looking to replace. Note there is a small o-ring seal on the switch when you remove it. There should be a Black & a Green wire coming out of switch.
Buy a new switch and use a sealer like permatex on threads when installing it.

 

problem still persist. Don't know why as i did everything. thermostat works, fan works when jumped. left car idling until room temperature didn't jump to the H. I changed sensor with my spare y8 one.

 

Check fuse #15 in the under hood engine compartment fuse box. Should be a 20 amp fuse and it's for the cooling fan. Make sure car is cold first. Drain off about 3" of radiator fluid so you can uncover the Inside "core" (where the fluid goes thru passages and back out). Leave radiator cap off the radiator and start car up & let warm up. You should be able to see the water pump pumping fluid thru the radiator if your pump is working properly. If it is pumping correctly, it must be the coolant temp switch. Is the switch you tried the right one for the motor you have or is it for your old motor ? Are they the same ?

 

I use the one from my old y8 but i have another spare one from my y7 hatch i could use. and they're both the same. i'll give it another try but im gonna check my fuse and everything again. my motor doesn't over heat when i let it idle for a while. so i know my thermostat works. i'll check this and adjust my tps all together. need this problem solved so i can get driving.