Need more information than that. Try posting your problems in the trouble shooting section.

You could have a bad CAT

 

Problem #1.............driving around with a CEL.
Go get it read........and as Razz points out, putting it in the right section would help.

 

so what's really triggering the coolant light?
had a trip to seattle from vancouver over the weekend.
had occasional coolant light in city, however, had no light on hwy when driving with cruise mode (6th gear, just under 4k rpm).
redlined couple times after roundabout near bellingham. no light.
stopped at intersection, the light came on for few senconds then off.
is this just ramdom on and off? or is the faulty sensor still picking up something?
byw, only managed to see one rx in seattle area.
blue one passed by at green lake way and N. 50th st.
mine was phantom blue.

 

You know whats really funny;

I actually had the coolant light issue too. I bought the car about 3 months ago, and the first longer highway drive I went on the light came on. From that point, the light came on pretty much every day when I would redline it. It lasted for about 2 weeks, and I didnt think much of it because Mazda had said that it is a common issue and not to worry about it. Its funny though cause like a week later it just went away and hasnt come back on since. Its magic!

 

Reading comes to mind! https://www.rx8club.com/series-i-trouble-shooting-95/coolant-bottle-greatest-secrets-revealed-182793/

 

Still wating for the expansion tank to arrive...
Parts for RX-8 here in Portugal is like finding water in the middle of the desert...

 

Been a bit off the internet for some tme but just want to inform that my RX-8 has received the new expansion tank and all was assembeld perfectly.
No more coolant level warning on the dashboard.

 

In case anybody wants to know, the same problem happens on the series II. I've had the light come on and off a few times when redlining on my '09. Seems to be random. Coolant levels near max. Only at 23k miles. Normal temps.

 

09 R3, coolant light was lighting up during high revs in neutral[0]. Coolant was full, but the nuts holding it on were loose (one very) allowing it to move. Tightened them up and it's off.


0: Don't do this, I was uhm... testing my new bhr midpipe.

 

I know a place that sells the coolant tank for THE LOWEST price around

Paul.

 

My 09 does the same thing but just driving down the road, all I have to do is the nascar tire warm up move and it goes away ;-) Which I really don't get because it's full but whatever lol

 

Hi, I have the same sensor issue and want to disconnect the sensor. I thought this would be a very simple task given how many people on this forum say they have done so. I'm normally good at such things but this has me completely stumped! I've read the manuals and it states connectors can be disconnected by pressing or pulling the locking lever as shown, except in my opinion it doesn't show it very well!

It does look like there is some sort of latch, and I've tried pressing, pulling, using a screwdriver, all sorts. I simply cannot get it to come apart! What am I doing wrong?! I must be missing a trick somewhere. I don't want to use excess force and break it completely.

I was really looking forward to getting rid of the annoying light, but now I'm left even more frustrated by my inability to perform such a simple little task! Any help much appreciated.

 

Find an old car guy. Have him show you.

 

Hey,
Not sure about your climate but warm it up with a hair dryer or heat gun. On my 2004 I can remove it from the left side if the tank before pulling the two connectors apart. Use a very small slot screwdriver.
If absolutely needed : two people, one with vise grips on each grey connector, the other depressing the locking piece with screwdriver. Pull straight. No twisting.

 

My coolant light came on. I unplugged it after looking for a leak (No leak). I use the gauge for temp on dash. That sensor is very bad undependable. I just unplugged the annoyance, no problems since and it is nice not to focus on that damn light.

 

As long as you know that the so-called gauge on the dash is a dummy gauge. By the time it moves from it's normal position, it's too late.
Yes, the float goes bad in the bottle and is only there to warn you if coolant is too low(not temp), so you're okay if you unplug it, just got to check the level often.
Back to that gauge, don't really rely on it. I mean if it's all you got okay then, but you might want to think about get a "real" temp gauge.......especially being in the mountains.

 

One of the side effects of the sensor going bad is giving false positives coolant level wise while temperatures approach the 190-200 range.

Don't ask me how I know. Paul hooked me up with a new bottle this week... along with a REmedy pump and thermostat.... now to get a thorough a$$ flush done... hopefully good enough to back flush my heater core at the same time.

 

Mazurfer has the most common sense remedy. I unplugged mine and plugged it just far enough to not engage for my emissions. I open my hood every day before and after I drive my 8 and I drive it hard. Your correct , if you watch your gauge and are under the hood every day that sensor just becomes an unneeded irritation. This issue is a dollar waiting on a dime.

 

The same thing has happened to me. My radiator coolant light sensor comes on minutes after driving it. I looked at the warranty book, and realized it isn't covered because I have owned it longer than 5 years. I didn't even bother asking the dealer how much it would cost to repair it. They said the level was good, and it was simply a faulty sensor. They recommended for me to unplug the sensor if it bothered me.

I first noticed the light came on two years ago when I was transporting 2 of my larger friends to Anaheim (one weighing 230 lbs, and the other weighing approx 330 lbs). I am sure the coolant tank permanently dropped a little, setting off the sensor light. Keep in mind, 98% of the time I am the only passenger in my vehicle.

Anyway- I like this forum a lot. I didn't know that replacing the radiator fluid tank will solve the problem. I understand you can find one for approx $110, and the labor is probably about an hour ($80 at an independent mechanic).

I am not sure if I am simply going to unplug the sensor, or if I should replace the tank. That light does annoy me!