Random Overheating??
 

Okayy so my car is acting stupid again. The thermostat gauge is reading hot very quickly, as in in the mornings when I start driving, 5 mins later it's damn near on H. And I'm in Georgia it's pretty chilly down here right now. I'm not driving any differently or too aggressively. Strange thing is, the gauge moves a lot, it'll read hot then cool Itself down when I brake or even when I'm still accelerating, which is backwards. Other times I'll be sitting at a light, it'll get hot and when I take off the temp falls and will either stay in normal range or rise back up. Again all this is completely random. It's only been happening in the past few days. Got worse yesterday because not it gets to the first H mark (the one before the real H) and can stay there or ride around it and will cause safe mode to kick in so the car won't Rev past 2000. But if I let it sit or turn it off and then back on the temp gauge goes way back down to normal and the car drives just fine until the gauge reads crazy again. I have a fairly new water pump and the radiator, coolant temp sensor and coolant hoses were replaced about 2 weeks ago. Did coolant flush of course. Also did a oil change this past weekend and replaced filter. I don't know what the problem is but it needs to be fixed asap as this is my daily. Please help. I love my maxima but if it keeps showing its *** might have to let it go.

I think you have air in your cooling system. You need to bleed the air out of it. Remove the radiator cap while the car is cool. Lift the front of the car on jack stands. Run the car for 15 minutes or so. Add coolant as needed.

^^^ what he said.

Its most likely related to the work done to it. Was it over heating after the water pump& radiator were "recently" replaced? Or only after changing the ECTS and hoses?

I changed out my radiator and upper/lower hoses very recently. You need to slowly pour coolant into the radiator. I poured mine slow enough where I practically needed no burping. Also make sure your hoses are nice and tight. Mine weren't tight enough, making me think i did a bad job and still had a leak but that wasn't the case.

yea but the air should have escaped into the overflow tank/reservoir. I would add more coolant into the reservoir or the radiator as others have suggested.

The only thing that hasnt been replaced is the thermostat. It could be stuck closed or cracked barely open and the engine fan is the only thing keeping you from overheating.

The air will NOT get out through the radiator or overflow tank UNTIL the front of the car is raised like I said. Lift the car or idle with the car facing up a rather steep hill