On Monday I was in town driving and I stopped at a drive thru, while I was waiting I noticed my needle was more than 3/4 of the way to overheating so I turned on my heat full blast and it dropped a lot but after a minute or so I seen it creeping back up so I left and went home. Got home and let my car cool down and checked the oil and my coolant. It seemed fine but i went ahead and drained my coolant and put a fresh bottle in there, my oil was recently changed not long ago but the level was Slightly low on the dipstick so I added another quart that I had laying around. Checked my thermostat and it appeared to function how the video I watched said it should. It stayed open when it was in hot water and it closed slowly when I took it out. Does that mean that the thermostat is still good for certain? like just because it passed that test does it mean the thermostat isn’t getting stuck while it’s in my car? I Reinstalled the thermostat and drove it up and down my rode for a like 10 minutes and it didn’t go past halfway so I just called it a day. Drove the car last night for about 30 mins after the sun was down and the needle stayed halfway until when I was almost back home it was going up just barely over 1/2 way so I turned the heat on and it went back down and was fine got home without problems. Today I tried driving and barely got down my road when it began getting hot very quickly and turning the heat on did not help whatsoever this time. Turned right around and went back home. Let it cool off for 3-4 hours and checked my coolant and oil level they are both fine still, started my car to do diagnostics and the needle was already at halfway when I’m pretty certain the car should have been fully cooled off by then, I hooked my car up to the diagnostic tool and got the live results and the coolant temp was at 161 degrees but the needle was 3/4 of the way to overheating. Does that mean it could just be a bad coolant temp sensor? I couldn’t see the other stuff/codes on the scanner tool because it began overheating and I had to turn the car off. When I look up online normal coolant temp it says 195-220 degrees but the scanner tool said coolant was 161. Also while working on the car I noticed my fans were powering on and off over and over like every second (when I noticed the car was still cold and the key was only turned halfway not fully on) I turned the car off and the next time I started it the fans were off. I started tapping on the fan controller box that’s on the radiator and the fans would begin turning on or off depending how I tapped on the box. Looked at the fan relays/fuses and one look fine but the other fuse had a slightly tinged look on two of the connectors and looked like it had some small burn marks or something but didn’t look that bad. The inside of the fuse box doesn’t seem burnt or anything either. I’m not really sure how to test the relay, I have a multimeter but not gator clips or anything I can hook to the relay to give it power while I’m testing it with the multimeter. any ideas would help. I reinstalled the relays after looking at them and now when I turn the key halfway or even if I start the car both fans are running.

I’m not a mechanic at all, I’m young and this is my first car I bought and I’m just trying to go off forums where other people had similar issues and watching videos but so far no success so any help would be really appreciated

 

Okay, so I narrowed it down to my radiator fan controller module. I replaced the thermostat and the fan module. I was driving it fine for a few days while I was waiting on the parts to arrive, I drove with the thermostat out and the same radiator fan controller for like 3 days and everything was fine no overheating. Well after I put the new fan controller and thermostat in, my car is now sputtering when I start it. If I hit the gas it will idle, I tried driving it down the street everything seemed fine but when I went to turn around to head back home the car went like limp mode right in the middle of the road as I was backing up. Had to put it in park and turn the key which did make it start but it was sputtering so I just hit the gas and got it back home soon as I pulled in the driveway everything died and power steering went out. Tried removing the thermostat and fan controller and reinstalling the old ones back but it’s doing the same thing now even with those. What could it be ?

 

did you disconnect the maf or something else in the process?

 

Head gasket? Get a tester for exhaust in the coolant.