I was driving my car perfectly fine when all of a sudden the obnoxious add coolant buzzer starts blaring. Pull over turn car off pop the hood and see if there's any leaks or anything, nothing. Start the car back up coolant buzzer is gone. I limped the car back to my shop just in case and let it cool down then checked the coolant at the thermostat fill neck, I haven't lost any coolant, there's still coolant there, the car doesnt overheat in the 100⁰ summer. So I'm wondering what caused the buzzer to go off, faulty sensor or what?

 

The sensor that gives a warning sound is located dead center top of the radiator. It is a cheap 10 dollar sensor still available. . . .Change that.

Watch the overfill reservoir. .. .Notice if it keeps getting filled up past where it should be. That is a sign you are pushing water into the over fill reservoir which is a bad thing.

Make sure you are full with water and have no air bubbles in the system.. . . . There should be a bleeder vent somewhere to get the air out during coolant filling.

 

The buzzer has 3 circuits that activate it. coolant, oil, tach redline if I'm not mistaken.

 

it was both the add coolant light and the buzzer, I just did an oil change 2 days before this happened and it is always topped up on oil so I know that's not it and I was at like 3k rpm so I doubt it was redline. Thinking it's just faulty sensor as it has happened again

 

Does it sound like a babbling brook behind your dashboard? If so, you might just need to burp it.