Coolant Light on Dash
 

Okay, so I keep getting a random coolant light on the dash every now and then. It gets more frequent everyday. I have checked the coolant and everything is fine? Does anyone know where this sensor is? I want to check the sensor before I go all the way to the dealer. Thanks.

i believe if you add just a touch of coolant the light will go away, even though it looks ok.

Cool, thanks.

The sensor is on the bottom of the overflow bottle.
Mine started freaking out a couple of thousand miles ago. For a while, over-filling the reservoir would cause the light to go out, but now it is on most of the time.
I am running a bigger radiator (that should make no difference to the level sensor) and a higher pressure cap (same), but the intermittent light started before I added either. It started on motor #1 and is the same on motor #3.
It definitely isn't a level issue or air in the system - the light comes on while the car is just sitting there with a normal amount of coolant in the bottle.

A friend here in town that is a tech at Berge Mazda says he has started to get '8s in with the same problem at similar mileage.

Yeah, mine seems to only come on when I am hauling ass (which is most of the time). I freakin' hate dash lights so I hope this is not a issue that cannot be resolved. I wonder if the dealer will give me shit since it probably will not come on when they have it.

i had the same problem so i took it in to mazda they said it is normal because the engine sucks in so much coolant when you get on it that it trips the sensor as having low coolant.mine would come on for about two minutes then shutoff.thats what i was told sounds pretty legit to me cuz the coolant is not low or anything.
Funny i just started a new thread asking the same question then i took Mugato's advice and here i am.....

There are two things wrong in that explination.

1) The engine does not "suck in" coolant. It recirculates it. You can't "suck in" more coolant that you are already recirculating in a full system. Depending on driving conditions and temp, the coolant may be deposited and then drawn back into the system in small amounts from the overflow tank but no where near the level that would trip the sensor. Something is wrong with the car. My guess would be the sensor itself.

2) If this were true, then every RX-8 would have that issue. I've owned two, neither had this issue, nor has any other one I've driven when I "got on it".

Its the sensor. A bunch of folks here in the southwest are having that problem.
The entire overflow bottle gets replaced because the sensor is integral.
I just unplugged mine. It doesn't tell me anything useful.

one member had the same prob...n turn out to be the sensor was dirty..no more prob after cleaning the sensor

How would one go about cleaning this sensor as it is molded into the bottom of the tank?

My sensor light is permanently on, how does one disconnect it as MM has said its as useless as tits on a bull :)

Dealer just changed mine. Due to random coolant light activation.

Did Karl have the bottle in stock? What was the internal cost?


https://www.rx8club.com/attachment.p...1&d=1182664209

Could just be sediment . If you took out the tank then fill it 1/2 full with water & shake the bejesus out of it ............ - might be worth a crack anyway .

Tried that. No dice.
I dried it out and sprayed it with contact cleaner too.
The float isn't sticking, its an internal failure in the switch.

No, they had to order the new bottle, not sure on the price.
I got the new overflow tank because coolant had leaked into the sendor and would short it out, causing the light to come on.

I had this issue once... Really scared me too... It was after some "spirited" driving, while I was waiting at a red light. I got the coolant light for 30 seconds and then it went off.

I'm mostly worried that I didn't put in a good mixture of water/coolant, but I haven't seen the coolant light in weeks, so no worries so far...

I was talking to another 8 owner and he's having this same issue.
Under load (Higher rpm's) for an extended period of time, the light would come on and then go back off, after normal cruising.

I'm seeing the same thing - spirited driving of say 7k rpm for over 30 seconds or so equals coolant light, drop the rpm's and the light goes away. A double check of the coolant level shows that is not the cause of the problem.

The temperature gauge shows no increase in engine temp so it does sound like a misread of a sensor as opposed to an actual issue.

These things are dropping like flies around here.
Coolant overflow bottle replacements are starting to catch up to engine replacements for the #1 warranty issue at my local dealer.

But I hope it's not starting a trend. Get a new overflow bottle,get a new engine.:spank:

I think they're up to Revision H now. the whole coolant overflow bottle.

Lucky I dont have this problem.

The cost of the coolant overflow bottle is around $400.00 aus :banghead: so simple disconnecting the sensor solves the problem and ..........costs nada

Thanks MM for the pics but i do preffer your avatars :)

Ben

Any time.
Just make sure that if you unplug the sensor that you stay on top of the level in the bottle and aware of your engine temps.
Don't let an unknown boil-over claim your motor.

I also had the light, but it was at cold startup in the morning. Stayed on for about 30 sec. then I haven't seen it again.

Anybody know if there is a TSB being worked on? Sounds like this is an issue. Certainly one that I will get fixed before the warranty runs out!

Sounds more like your coolant level is a tad low. Just low enough to set the sensor off when it's cold and display the light. But as the engine warms up and the coolant expands, Just enough to turn the light off.
Have you checked the level?
Do you have warranty? If you do then take it to the dealer and say,,,,
"Can you fix this please." :spank:

check this out
https://www.rx8club.com/showthread.p...=1#post1945299

Hmm...having this problem too. Goes on for about 10-20 seconds occasionally, and then goes off, but my coolant level is fine...bleah. Will have to see what I can do about this.

yah, mine did that, we topped it off, and it hasnt been back on since. its been prolly 6 months too.

hey mazda maniac are you talking about the berge ford here in mesa arizona? because I went their and the tech that i talked to was Ernie. he was great.

Karl is my guy over there. He's on the forum here as "rotaryman25".

I bumped up the coolant level a little and so far, so good. We'll see how it goes.

i have the some problem, i posted it under the thred of "cooling system" i am going to change the all unit ans see what will be the results.
i wonder why Mazda doesn't publish any article about it?
did any one complain?

I had the light once and it scared the hell outa me because I was also doing spirited driving. Turned out that coolant was leaking out of the adapter from the coolant/fan mod because the clamps weren't far enough up. my mistake..

They ended up replacing the whole reservoir and sensor.

^^ Yep, that's the only route.
A TSB is forthcoming.

is it the reservoir you guys refering to that needs to be replaced? does that include the sensor?

http://www.trademotion.com/partlocat...layCatalogid=0

yep,

that is the one.. really it is not that bad of a price..

but i will take mine out and try to clean the sensor.. have done this with other cars...

i have almost hit 75k miles.. and the light comes on about once a month..

beers :beer:

Just had my car in for this today, they replaced just the overflow tank pressure cap and the issue seems to be resolved.

im starting to experience this too with semi-spirited driving. its always on the highway, and usually when im cruising at speeds of 85 or so for a few minutes, never when im really pushing or getting on it. if i back off to around 70 itll go away. however, i live a bit further out and now and again when im coming home late i enjoy very spirited trips along the country roads where i am easily braking into triple digits, and there are plenty 110-40 moments and even a few 120-0 stops in there. ive never experienced the light in this situation, which seems odd.

of course my car is just a few thousand out of warranty, given that this is a known issue has anyone tried to get mazda to cover this?

screw it, im just disabling the sensor. is the it just one of those plugs right next to the reservoir, and if so which one?

not a very wise thing to do...you mite have a leak during drive and not know abt it until you toast your engine

If you don't notice it until you toast your engine, the light isn't going to help you.

There are two sensors in that location - one is attached to an aluminum filler block for the A/C. Its not that one.
Just unplug the other one and check your coolant when you check your oil.

good advice, but i check my fluids once a week and my coolant has never moved

thanks maniac, and nice av :)

Goodthing i caught this thread.

I would really like to know how common this is.

We haven't had this problem here in Calf in our club.

I saw the light for the first two times today while driving spiritedly. After I short-shifted the light went off.

I wonder how many people that have this issue have higher pressure radiator caps.

hate to resurrect a thread but has anyone got anywhere with this? i just started getting this light, but fluid levels are good. i am going to probably take it in next week. if i have removed the vfad do you think they will give me any probs for this?:Wconfused i usually preach the better safe than sorry but i do not feel like removing the bumber again.. yeah, i'm being lazy..

add another to the list.

havent seen it recently, but up until 2 months ago or so, i had about a 2-3 mile hill climb to AND from work everyday. when pushing the car up this climb(5-6K rpm and over) i would get the light. light dies 3 seconds after dropping to idle.

never happened anywhere but that one long hill

Just unplug the sensor and forget about it. Its not worth the $115 for the new bottle plus labor.
Just remember to check your coolant level every couple of days.

I agree, not worth the $, nor the hassle of taking it to a dealer and watch them scratch their heads.
If it ever surfaces again it will get unplugged. I'm sure its only a matter of time.