hi, i have a 98 civic ex coupe d16y8, with aem cai, catback, etc...

I am just wondering how come my engine fan come on repidly, its only like 15 degrees outside.

Thx

 

I don't think your fan is dependent on the temperature outside when cutting on. Your block is going to get hot no matter if its 115 degrees or 15 degrees outside, and your fan cuts on to get some air flow and dissipate the hot air around the engine block. You will notice that the air around the engine block is still alot hotter than the air outside.

 

When your engine coolant gets to a certain temperature, your fan will kick on to cool the coolant running through the engine.