Ok, I just finished up my Motor swap and my car is overheating now. I changed thermostats and fan switch and temp switch. Car didnt overheat with old motor and the motor i put in it didnt overheat in my old car. What can i check to get this fixed.

I already tested the relays with my Snap-on MT2500 Scanner and they work. I can go in and turn the fans on with the scanner but they wont turn on by their self. I used a diffrent radiator and fans when i did the motor swap since i sold the ones i had in it.

All help is appreciated.

Thanks in advance.

 

Make sure it was filled and bled properly. That's the most common cause of overheating issues.

 

I opened both bleeders on the hoses going to the water pump and all the air is out. I'm sure the coolant is circulating but the fans just wont turn on unless i turn the on with the bypass switch inside my car or with the scanner.

 

So, you are watching the temp with the scanner and when it reaches the ON temp threshold for the fans (226°), you see the fans commanded on but they are not actually coming on?

 

Yes. I'd watch the temp with the scanner and when the temp reaches the ON the fans wouldnt turn on. I replaced the relays and put the correct amperage fuses where they needed to be and now the fans turn on at 228° It appears I have a bad fan so i'm replacing it right now. Hopefully it works.

 

The problem with the fan issue was my lil bro put teflon tape on the sensor b4 he gave it to me. i took the tape off and the fans went to work. The both now turn on at 228 and turn off at 219. took it for a test drive tonight and it runs great stays cool.

Thanks for the help Rob.