Overheating at idle issue

[YeBoiSky]

Hey Everyone been a while since I've been on here but I need help cause I'm having an issue where my car is overheating on idle. The entire cooling system is basically all new, water pump was changed a year ago, thermostat and all hoses were replaced a month ago, ALL temperature sensors were replaced (the 3 on the tstat housing AND the thermosensor on the radiator). Now i just replaced that radiator thermosensor just last saturday and before changing it on idle the car would start to overheat and once it would hit the red the fans would come on. now that ive replaced it the car just overheats without the fans coming on at all or they will randomly turn on but shut off after like 5 seconds. I already did the diag as per the shop manual and jumped the plug that goes into the termosensor and the fans turn on when jumped so im not to sure if maybe i got a faulty sensor or maybe theres a different issue? Side note car stays completely cool when im driving and i was also wondering if i could use a spoon thermo fan switch that activates the fans at a lower temp.

[ShiRen]

Is the head gasket blown?
Id put the old thermoswitch back in, you confirmed everything else works.
Do the fans come on when the ac is turned on?
Did you burp the coolant?

[YeBoiSky]

burped the coolant when i changed the thermosensor, head gasket should be fine it didnt overheat for long, fans do come on with the a/c button since i have my a/c deleted i jus jumped the a/c pressure switch plug so that i can activate my fans with the a/c button. old thermo switch looks aftermarket aswell but i have one off a junkyard car that seems original so ill try cleaning it up with a wire wheel and throwing it back in

[ShiRen]

I wouldn't be so sure about the head gasket lol, I don't even mean to say that overheating is the cause, it's just an old, under torqued, copper gasket.
If you can activate the fans by jumping or with the ac button, then the only other variable is the thermoswitch, even the head gasket or air bubbles would just accelerate the heating, they mean nothing for the fans overheating.
If you want to test switches you can heat them up in water and check the resistance, and you can measure the temp of the water to see when it switches. I suggest dangling them in the water with a stiff metal wire, attaching jumper leads between the multimeter and switch, hanging a thermometer in the water, and wait for it to switch closed.

[YeBoiSky]

I'll give it a try. by any chance do you know if that spoon thermo fan switch would work for our cars? if so might as well buy that one

[ShiRen]

Literally any thermo switch works, but the normal threads and most of the other threaded holes in the coolant system, use bspt, and also the plug would have to work or be modified.
However, the thread and the plug are pretty common amongst Honda parts

[Benjamin4456]

Curious if you got it sorted out, my car has had a similar issue for a while (fans don't turn on until it's nearly to the red). According to the manual it's not "overheating" until it's in the red but it still doesn't seem right.

[Tonafish12]

Mine has always ran at about to 1/4 to 1/3 on the gauge while moving and while idling it'll go up to about 2/3 to 3/4 on the gauge before the fans come on. Honestly I think it's just normal for these cars.

[ShiRen]

I kinda just assumed that his gauge was in the red when he said overheating. If it's not in the red, you're not overheating

[Oldblueaccord]

Yes with temperature its a good idea to double check with another gauge or temp gun.

Cleaning the connection at the temp sender helps with accuracy.