Hi guys. So I've been dealing with this problem for awhile and have 99% narrowed it down to being some kind of electrical issue, after replacing half the cooling system 😅. So, whenever my radiator fans come on, the temp gauge jumps to 3/4 or higher. I know the car isn't overheating due to the fact my AEM gauge is still showing the temp going down when the fans come on. I know it's not a huge issue but I'm super OCD about these things lol. I've replaced the gauge cluster, rad hoses, both temp sensors, radiator, and thermostat as well as flushed the cooling system and refilled. I'm guessing a bad ground somewhere but I don't know where to look. Any help would be greatly appreciated!

 

Replace the Temperature Sending Unit.

 

already did

 

OP has tried everything I could think of to get this resolved.

 

I'm having the same problem

 

Is the thermostat still original have you even checked or changed the thermostat it's possible that your thermostat is not closing all the way. A opened thermostat will not let the engine heat up or build heat up and a closed thermostat won't let or allow the engine to cool down and to heat up and over heat.

 

Pretty sure the gauge is wonky or an intermittent short. It works randomly