So I just put a new thermostat in my car yesterday and the buzzer keeps coming on. Now I drove it most of the day and it didn't start till the ride home. I own a mazda rx-7 manual and did just like it said to do to get the air out of the system. The thing that is worrying me is it only does it when I slow down and stop. As long as I am driving it's fine. I'm going to replace the water pump tomorrow but would like some ideas on this since I'm going to tear it apart anyway. Plus I had no bubbling in the radiator.

 

Most likely, the air just isn't completely out of the system yet and you need to put some more coolant in. No big deal, just top it off.

 

wait till the engine is cooled down, top off the filler neck with coolant and let us know the results.