hey this past month, i have see that the car radiator light goes on after am running over 65 mph.
some times is when i pass 70mph.
i am worry i slow the car down as soon as i see the light n makes it go away.
i check the coolant but its full.
please help i dont know what to do.
oh and some times this happens when i rev the car too much....

 

do you have a scangauge to measure your actual coolant temps? Thermostat might be sticking.

Short answer -- don't drive until it's fixed or at the very least you have a better understanding of the problem. You'll end up needing a new engine over what could be a $50 issue.

 

Faulty sensor.
I had the engine coolant light come on during steady First Gear 8000 rpm cruise run (30 seconds)

The OEM coolant needle didn't even move.
My RB Coolant guage said 103C (217f)

As soon as I backed off the light went out and the temp dropped to 90c rather quickly.

I have BHR Radiator, Mazmart Tstat and water pump and a Buddy Club coolant cap.

 

When the engine is cold add a few cups of distilled water to the coolant reservoir.

 

It happened to mine when i drive over 60 mph and goes away when i reduce speed under 60 mph. It may have a faulty sensor or your losing coolant. Some says it's normal.

 

I don' t see how coolant temp will affect this, as far as I'm aware the radiator light is only affected by the coolant level? The level sensor is a common fault on RX-8's the problem is, the sensor is moulded into the header tank on the radiator, so you have to replace the entire header tank. If you're like me and don't want to replace the entire header tank, then just unplug the sensor to stop the light coming on and just keep an eye on the coolant level by manually looking, always check the coolant level when the engine is cold tho (preferably left overnight).

 

Ahh, the famous Lincoln Memorial. As Vulcan suggested, keep an eye on the coolant level when the engine is cold. Also, this have been beaten to the curb. Use the 'search' option next time before starting another thread.

 

There's a service bulletin on this. If your car is still under bumper-to-bumper warranty you can get the tank replaced for free.

If coolant actually is low, don't add just water. Add the right mix of coolant. If your radiator cap has a "FL-22" sticker, that's Mazda's own brand of green 55/45 glycol mix. You can use that, or any name brand green glycol coolant, properly diluted.

Ken

 

poor water hose inside the reservior, clean the reservior, fill the bottle again, if that doesnt work disconnect the plug and watch the coolant level everytime u check oil, or go to warranty for a new bottle,,

 

It's actually a float that loses it bouyancy and fails to float.

There was one post from a member who cut his reservoir open, replace the float with a wine cork, then plugged the hole with a bolt and some fender washers and some rubber gaskets. Since the reservoir is on the pressurized side of the system, I'd be leery of cutting and patching a hole.

The two other succesful fixes discussed here are replacing the reservoir with the new version, or pulling the plug.

That's a third fix. Leave it alone, and recite the Gettysburg Address every time it comes on.

Ken

 

thank you everyone. sorry i stared this thread but i needed to know.
but thank you for every ones help.

 

So what fixed it or what did you try? Did you try adding a little water?

 

Same thing is happening to me. The light will come on for a couple minutes and then shut off and then come on and then shut off in a cycle. I'm guessing it's just a faulty sensor.

This started happening right after Mazda replaced my engine so I'm going to talk to the service rep and try to blame it on them to see if they will replace it haha.

 

Ken,

The next person who post and ask, I'll just cut and paste your quote above.

 

First time I've heard that one! Thanks.

 

i added more, but it didnt work
i am taking the car with my trusted mechanic.
lets just hope is something that can b fix.
i will post here after the car is fix n what was done to it.
thank you everyone again..

 

Like what Ken said, and what almost everyone with the same problem did:

 

Or......just click this link!

Search rx8club for coolant bottle via Google

yes, it will lead you to my thread, and you really only have to read the first post!

 

Wow great thread Mazurfer...
I didn't even know we had a coolant bottle.

I was using that to boil my veggies in