I filled it with coolant last week.......but this morning the light/buzzer went off again. I added maybe half a pint of coolant before it was topped off again so that tells me that something else is wrong.

Any help?

 

I had the same problem and i finally like screw it i hate to saw it i'm scared of it. lol. No i think it is a sensor on the radiator what series do you have

 

Yeah imagine hearing it at 4:30 in the morning half asleep with a hang over.

it's a 91` GXL FC3S as far as I know.... I bought the car last month and I don't know too much about Mazdas yet, but I"m learning something new every day.

 

Thermostat?

 

Oh there is a sensor on top of the radiator and i'm pretty sure that is what is going wrong.

 

You have air in the cooling system,and it is a Pain to get out.Give the car a good Burping of the Lower and upper hoses,while you have the Engine running and get the thermostat to Open and circulate Coolant.another Thing is to have your HEATER on Full Tilt to get the coolant to circulate in there too.(Sometimes a source of trapped air,especially when Replacing Old to New Coolant).Once the thermostat is open,and the coolant is circulating,What I did was shut the car down.Pop the cap on the Thermostat housing,SLOWLY.Add coolant there and squeeze the hose repeatedly until the cooolant is at the Very Top and about to overflow.Place the cap on and Toss a bit of coolant into the overflow jug.When you start the car NOW,the Buzzer should not Go Off.If it does then you have to Burp the system again.another note is that the sensor could be faulty too...Take the car for a spin.Watch the temp level on the Gauge.Wait a bit after Shutdown to make sure that the Coolant level is Up where it should be,at the Thermostat filler neck,and there is enough in theoverflow too. It's a Screwy Method,but it has worked for me,Very Well.Others have different Ways to fill the sytem and top off too,.among them Most likely is Kevin Landers..@ www.rotaryresurrection.com hit the TECH section.He should have some info on how He does a Cooling system coolant replacement/Troubleshoot,etc..Good Luck.STYX!~

 

Well, in 91 there was no GXL.. but.. to point out the obvious, sounds like you have a cooling problem.

After the buzzer goes off, have you checked the levels? Also. are you checking the level of the overflow? or the radiator itself?

If you change your T-stat (not a bad idea) use ONLY mazda OEM parts. available from mazdatrix.com, atkinsrotary.com, etc. Napa sometimes has them, but thats rare.

The S5 (89-91) cooling system is pretty trouble free as far as getting air out...

So, the grim possibility is that your engine is drinking coolant and/or replacing it with oil. Check the reservoir for oil drops and check your oil for water.

 

If there's no GXL in '91 then I wonder what the hell I have...

 

Well, it wasn't called a GXL. It was base, package a, and package b. If its fully loaded with leather, its package b. Fully loaded with cloth, package a... no tilt, fogs, etc, its the base.

All NA cars in 91 had no external badging for their trim code such as "GXL" or "SE", and the Turbo cars weren't called Turbo II's. They were just the "Turbo Coupe". 91 was a weird year.

 

That annoying buzzer you hear is the low indicater sensor. You clearly have a slow leak somewhere. The sensor sits high, so once the coolant level drops below the sensor (which a slow leak will do, been there done that) the sensor sounds off to let you know you have a problem.

Or you can pressure test your cooling system and pin point the leak.

 

ok so I guess I have the "package b". It has the weak stock cd player that skips over every bump (but looks cool stock so I'm keeping it for awhle), the leather seats, fogs, etc...

so how do I burp the hoses? Just disconnect each hose on one side for a minute to let whatever circulate out?