'04 Honda Civic-1.7L
First the car started overheating only it was sitting in idle. As soon as you would go or if you revved the engine the needle would immediately drop after a few seconds. Replaced the thermostat. It seemed fixed, but started doing it again, put in a new thermostat incase other one was faulty. Still having same problem.
The system was pressure testing and everything was fine. Then had the system flushed and new thermostat put in. It worked for about 150 miles and started doing the same thing.
Brought it in for the water pump, the old one was corroded and warped so it seemed like the problem. After about 100 or so miles still overheating when idle.
We had the radiator replaced, the old one was complete junk, thermostat replaced too. I drove it like normal in town for a day, the next day it started overheating, this time it was doing it while driving, got to about 3/4 up. Turned the car off for a bit, and it didn’t do it anymore on the way home.
Today I was driving and it was fine for 4 miles, I sat idling for 1 minute, after driving 1 more mile it started overheating, temp gauge got to halfway. I parked it for a bit and started driving, there was no heat coming from the heater, I had it full blast, nothing but cold air. The car started overheating again, once again halfway. Parked for about 3 minutes and then turned it on, temp was fine and it was blowing full heat out, the car temp was fine the whole way home, no more overheating.
The next step we will take is to replace the head gasket and/or heater core. Is there anything else that this could be? Literally the same week the overheating started, the rear lights were having issues and one time there was no power to the windows. Then the door locks would stop and then work again intermittently. The door locks no longer work at all. Not sure if it is just a coincidence, maybe everything is breaking at once. But there has been no loss of coolant and the oil and coolant consistency have been normal too. Any input would be appreciated!