Rep Power: 0

Update: 2019

Initial Issue:
Car was overheating, I rev the engine in order to keep the temperature down. This is now the only issue with cooling. Well there's one more,
I'm not 100% sure if the cooling fans turn on whether the AC is on or off. I have noticed that when the AC is off, the cooling fans do not turn on.
I drive with the AC or heat on at all times except at night. I changed the fan when I noticed that it wasn't working.

Since then:
I changed a few things with the 2002 Honda Civic Ex and I remember hearing a whistling or like a high pitched whine type sound shortly after
the cooling fans turn on to cool the engine down. I have been getting by not having the car overheat by revving the engine when it starts to overheat,
but I feel this sound has something to do with why my cooling system is not functioning properly.
So far it has been about 1 year since I changed the cooling fans, head gasket, thermostat, radiator, water pump and belts. When I got the head gasket changed,
I had to rev the engine to cool it back down when it is idling. Other than that, the car doesn't overheat at all.

Here is the link to the video where the car makes the sound:




Please help me diagnose this sound! I love this car and I feel as though this will help me fix the issue once and for all.

 
Rep Power: 119

Start by making sure the ECT connector is even plugged in.
You replaced a lot of parts, you might have forgot to reconnect it.

Usually pretty simple
bypass ECT switch and see if fan turns on, replace switch.
bypass fan relay and see if fan turns on, replace relay.
Test wire harness power to the fan.

As too having to rev the engine, that sounds like you might have a large air bubble in your coolant or you installed a non-Honda waterpump that simply was worth less than you paid for it.