I just got my Koyo radiator installed a couple days ago and I just noticed that now after long drives, the fans run for a while after shutting off the car. I read that the fans are supposed to come on for 10 min after the car is shut off if the engine temp reaches 226F but I never really noticed the fans ever turning on before the new radiator. While driving, the crappy stock water temp gauge actually seems like it's even a little lower than when I had my stock radiator so I think the new radiator is working properly and I would think that my engine temp would be even less likely to reach 226F. Also, it seems like my car hesitates more often at 3k rpm now than before. Any ideas? Should I just take it all apart and check the wiring to the fans?

 

I have this problem too and i have a stock radiator. I try not to leave the fan running after i shut it off, afraid it may stay on after i walk away from the car and drain my battery. So i turn it back on and shut it off again. It usually does the trick. I'm not too concerned about the problem. Should i be? Any other responses?

 

I'm not sure about the fan staying on but as far as the 3k hesitation being worse. Thats probably due to the fact that your new radiator really is working well thus your motor is running cooler, probably taking longer to warm up as well too. If I recalll the 3k hesitation is usually at it's worst before the motor is fully warmed up. This is just my theory of course I could be wrong.