A few months ago I replaced the water pump because it started leaking. It continue to heat up 3/4 of the way at random times then went back down. I replaced the thermostat recently with an OEM one. I had replaced it before with an aftermarket. No white smoke when start in morning or when driven. I also replaced the air filter. Checked all sensors and relays. Fan’s come on. AC works. Heater works. What could it be? No signs of oil in coolant or coolant in oil. It happens randomly but a lot more lately. Sometimes higher RPM’s will cool it down sometimes it doesn’t. What can it be? Mazda v6 is the car.
No coolant leaks. Checked the coolant before and it would still be full for over a month. I recently replaced the coolant so it’s top off. I checked it. I will try bleeding the system. I did tried to bleed the system following instructions the manual before with the other thermostat and it still overheat 3/4 of the way then I would cool it down by carefully spraying some water over the radiator.
I checked the temperature gauge and I do believe it’s working. The car does get very hot. The fan(s) do come on at certain temperature.