essjay

Hi Guys,

I recently bought a 1984 GSL-SE and i'm having a small problem with my coolant level sensor.

The coolant is topped up, but on a cold start(10*c) the buzzer and light will sometimes stay on for up to 5 minutes, and occasionaly while driving it may come on for a few seconds.

This is a minor annoyance but i'm looking for a sure way to fix it or buy a replacement sensor, or if all else fails maybe just ground the sensor and check the coolant every week.

Could someone link me to where i can find this part?

and to just double confirm, the sensor i'm having trouble with is the one on top of my radiator?

Aiki

I would first make sure that any part of the wire is not exposed. Then, check to see if you don't have bad grounds. Make sure to clean/wire brush all ground areas (I'm not sure where for GSL-SE. Check your wiring diagram). The sensor itself rarely goes bad.

essjay

So i've grounded the wire and the light no longer comes on, which confirms no other problems with any connectors.
The Sensor had some epoxy on the top and you could see exposed copper... so i assume the previous owner has tried to repair it at one point(from the looks of it didn't do a very good job).

Could anyone give me some direction in buying a part like this online? does it need to be a specific coolant level sensor or just a generic mazda one (like any year will do)?

hanman

I would bet your problem is not the sensor, but simply you have air in the coolant system. Trying burping the coolant system.
In fact. When it is cold, pull out that sensor (on top of the rad) and see if the coolant is all the way to the top. I bet it's not. That sensor is very simple. When coolant touches it, it grounds. No coolant, no ground and it sets off the buzzer.
By the way, that sensor is the same for all RX's, so they are a dime a dozen.

essjay

if i start it without the sensor in won't it overflow out of the opening? is that how i go about "burping" it?

i'm new at this obviously.

hanman

No, not with it running.
What I do, is with the car off and the coolant system sealed, I grab the upper rad hose and squeeze it a number of times. Basically, trying to force out the air pockets. You can also remove the coolant line at the throttle body and fill it with coolant until it runs out of that line.
What I do now, is I use a tool from Lisle corp. It is a funnel that seals to the filler opening. You just fill up the funnel and let it take all the coolant in. You can even do it while it is running. It won't allow air in the system. Works great.

And, it still is possible for your sensor to be bad. But, I wanted you to make sure it wasn't just air in the system, because that is VERY common.