Hey,
I have an 86 Gx. Ive had this problem for a bit and what it is, is the add coolant buzzer keeps going off, i replaced the thermostat and the sensor which i bought from rx7 heaven. The thermostat i got from mazda. The buzzer goes off when its at idle but when i hit the throttle a bit it goes away then comes back again? Could this be air lock in my rad or hoses? Its ******* annoying having this buzzer go off everytime i drive, and it sucks when im driving with people, so annoying and hard to explain to them...wutever. If someone can help that would be great. I searched but i couldnt find a good answer...thanks alot.

Nick

 

Take a good look at that little single wire coming off of the sensor on the top of the radiator. Now follow it as far as you can, all the way down to where it meets the harness on top of the rail. Any cracks or frayed wires? How's the connection at the sensor? Loose, feels like it's about to fall off?

This is assuming you know that the coolant levels are good in the radiator. It must be topped off at the filler neck cap on the t-stat housing...

 

I get this problem whenever I open the radiator cap when the car is off. Basicaly what can happen (and happens alot if you don't bother bleeding the coolant system) is a air buble gets trapped in the system. The water pump pushes it all the way around, and it will hit the coolant level sensor. Whenever the buble hits the sensor, the sensor says "No coolant, OH **** BUZZZZZZZ!!!". You get the idea. You blip the throttle or give it some gas and the waterpump has enough suckage to pull the buble away from the sensor. Couple minuets later at idle the buble eventually meets back up with the sensor.

On an s5 you can just open teh radiator cap on a cool radiator, make sure its full, then start the car. The system will push the bubles out of the open ratdiator cap.

S4s are more tricky, there is a bleed valve or screw that the FSM says to bleed the system with. I'm not familiar with the S4s so much though.

Goodluck.

 

Hmm...I've never, ever had to crack that bleeder screw to get air out of my system...Run the car, let her cool, add coolant if necessary at the filler neck. Done.

Maybe a bad rad cap could cause these problems...???

 

That could be too. Honestly, I've never heard too many FC owners taking the bother with the bleeder. I've always been able to get the sensor to shut up by adding more fluid while idling, and then closing the cap and revving it a bit. usually pushes everything out. Its just sometimes that buble isn't able to make it to the highest point (the cap, traditionaly) and instead will get stuck somewhere-- l ike righ near the sensor.

However, I was driving last winter and I heard the buzzer go off. About a minute later I realised I was burning hella coolant. turbed out the radiator hose cracked and was spewing coolant everywhere.

That buzzer is there for a reason, thats for sure

 

It took me a bit to bleed all the air out of my system after I rebuilt the engine.

Then I discovered why - one of the radiator caps was leaking! Replaced it, and it's been fine since. Look carefully for coolant leaks after a hard drive. They're easy enough to find with a flashlight, as long as they're external. It's shiny, wet, and smells sweet.

-=Russ=-

 

my entire engine bay smells sweet.......overheated last week......wasnt too fun...

 

Ok, sounds like you need a new radiator cap

The way I get the trapped air out is to fill, replace the cap, squeeze the upper radiator hose vigorously a few times, remove the cap repeat. When you finally remove the cap and its full your done. Usuall I need to repeat 3x.

 

Mine kept buzzing at weird times until I replaced the radiator, which had a tiny pinhole leak around the top that you could barely see. The buzzer is definitely doing its job. Make sure your overflow bottle is filled to the correct level too.