I am having a problem with my add coolant warning poppin up every now and then. It says add coolant, but my resevoir never goes down and only up actually. The engine never overheats since I bought a new thermostat and cap. So what is it? Maybe poor circulation? Water Pump? Defective Sensor? Please help and thanks in advance.

 

What do you mean the reservoir goes up? If its the sensor, then its a broken wire. Have you inspected the sensor yet?

 

Check the raditor itself for coolent not the resevoir.

 

I sure hope someone posts some info for you. I'm having the same basic problem and I'm not gettiing any help at all. Mine does the same. My radiator will drop about a quart but never lower. If I'm parked and the "add Coolant" light comes on, I can sometimes hold my rpm at 2500 or so and the light goes off. Make sure you have the belt that goes around the crank/water pump/air pump. I have heard that the impellers on the water pump can rust off. I think I'll try a water pump soon. The other option could be leaking coolant O-rings internally. Do the search. You'll get more help than posting.

 

It is very common to get an air bubble in the system. This will cause your problem. Are you using the little bleed screw on the passenger side of the radiator? Unscrew it and add coolant at the filler neck until fluid runs out. Then gently squeeze the upper hose from the bottom by the rad to see if you can "burp" any air out.

 

Also, you may have a small leak from the weep hole in the water pump. You can check from the bottom of the pump. If you see a small amount of coolant around the bottom of the pump, it's replacement time. Mine did this and it is frustrating and hard to diagnose because it was inconsistent.

 

Well I had something similar.

The overflow tank would be maxed out and would sometimes spill coolant onto the ground.

A new radiator cap worked for about 4 months.
Then the cap went bad again and shot all the coolant out while driving killing my engine and blowing a coolant seal.

I am beginning to think that I had a very small coolant seal rupture which over pressurized the system and caused the cap to fail. The car over heated and completely blew the seal then.

I would recommend to do a compression check and maybe star saving for an engine just in case.

Hopefully it's just something small though.
Good luck.

 

umm.. i smell rebuild

 

First-
What brand of cap do you have? The Mazda cap seems to be the only suitable choice as others do not seem to work correctly. Make sure you have a good (preferably new) cap.

Second-
describe the system you have. How many caps do you have? there are pressure caps (which relieve pressure by allowing coolant to flow into the reservoir, but then let the vacuum generated by the cooling coolant draw the coolant back in from the reservoir) and flat caps (use is dependent on what type of radiator and what year car) that do not relieve pressure.

Third-
Do you have a factory type radiator with no cap but does have bleed screw near the upper hose or maybe one of the brass aftermarket replacements which have a filler neck and cap but tend not to have the bleed screw (no bleed screw = air pocket = coolant overflowing into reservoir and add coolant buzzer).

If the coolant loss seems to be about the same amount being spit into the reservoir tank, then I would suspect a bad cap and an air pocket. The air pocket creates the overheating/overpressure problem but the bad cap does not allow the coolant to flow back in. One way to test the cap is to get the car hot then let it cool down completely. Open the cap and listen to see if there is the sound of air rushing in. If there is, then you might need a cap.

 

Then you'd better take another whiff.


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Please clarify. You said that bought a new cap and a new thermostat. Did you buy them from a Mazda dealership?

The aftermarket thermostats for our cars are garbage. Do not use them. And while I haven't heard comments as harsh as that about aftermarket rad caps, the informed consensus seems to be that using caps from Mazda is the best choice.


Please answer opelbits questions, and follow his instructions for checking for a bad cap...

 

ahahah =( yeah is probably teh caps im ghey

 

I had the same problem untill yesterday. Just pull the cap off WITH ENGINE RUNNING and then kill the motor. Unscrew the sensor from the radiator(top center with one wire) check the part that actually goes into the radiator and see if its dirty, use 320 grit sand paper and sand just the tip(from the bottom ring down) and all around the sides of the bottom part. If that doesn't fix it then you need to change your coolant, thats what I did. Its not hard.

 

I had the same problem as well and I had the cooling system flushed and it is fine now

 

That's scary......ADD COOLANT light was a misprint...... It should have read "Change engine" instead, usually this comes on when air bubbles pop right infront of the sensor causing the light to go on. Bubbles usually stem from the seals being cracked or blown......start saving my friend.....

 

my add coolant light kept comming on right after I replaced the stock filter with a K&N style filter

found out it was just a loose ground that was hooked up under the stock airclean setup that came loose

hooked it back up and things worked fine

 

I had the same problem. Make sure that you add coolant to the cap on top of the motor and not to the radiator. I did this and it went off.