While stopped at the drive through for about 3-5 minutes I noticed that my coolant gauge went from 1/4 to 3/4 then my fan kicked on and the needle went back down to 1/4. My problem is that the fan normally kicks on long before the engine gets that hot. What would the problem be?

 

Hi Knightrider03m,

Did you happen to have the A/C running? If you're low on coolant it can cause a rapid increase in temperature, so I'd check that first. Also look around for a slow coolant leak if you find that it's low. I'm not sure what kind of car you were driving at the time, but my Honda has two electric fans and I had similar problems as you when one of the electric fan motors died.

You can test the fan motors by running a wire from the fan directly to the positive side of the battery. You just have to disconnect the electrical connection of the fan and touch the wire from that to the battery and see if the fan spins. If you want to be extra careful, you should use a wire with a fuse so that you don't accidently blow the fan motor. I've done this without the fuse and not had any problems.

The parts store wanted about $100 for a fan motor for my car, but I went to the junkyard and pulled one for $8. It's still working well 3 years later.

I'm no expert, but that's my guess with limited information. Good luck.

 

The a/c wasn't running but I'll check the coolant level.

 

Second coolant level check. I'll bet you're low.