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Radiator coolant warning light

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Old May 12, 2008 | 02:34 PM
  #1  
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Radiator coolant warning light

Hi

Howdy as you guys say, just a quick question to all you US owners. Us Brits are encountering a lot of problems with the radiator coolant warning light coming on and remaining so for several minutes during driving.

I encountered the problem yesterday and again today. The coolant level was checked and was between the Min-Max level. The problem seems to occur during the higher rev range, but if revs are dropped or a gear change is made the coolant light on dashboard will go out.

The water temp reading is never high and is always in normal range. The guys over here think it could be either the sensor in the coolant tank, or possibly a leak from rad cap.

If any of you guys are, or have encountered this problem. Any answers would be apreciated.

Nige
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Old May 12, 2008 | 02:42 PM
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I believe the sensor is highly sensitive, so even though the cooler level reads ok if its even a hair under what it should be it'll trip the sensor. Did you try added just a couple ounces of coolant and seeing if the light still occurs?
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Old May 12, 2008 | 02:50 PM
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Hi

Thanks for the quick response, I did add a little extra coolant today, about 1/4 of an inch above Max level. I took car out for a quick run and problem is still present.

Nige
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Old May 12, 2008 | 02:54 PM
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mine will stay on occasionally on cold days.
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Old May 12, 2008 | 03:44 PM
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I have (had?) this problem for last few weeks.
Usually in 4th gear & above 4K, as others mentioned it will go away if rpm drops.
Took my car to dealership last week (massive power loss and many other issues) and they told me that they will replace whole coolant assembly – according to tech words the sensor is the part of assembly and can not be replaced alone.

PS
2004 6sp 45K on ODO
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Old May 12, 2008 | 03:49 PM
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Originally Posted by nilitara
Hi

I encountered the problem yesterday and again today. The coolant level was checked and was between the Min-Max level. The problem seems to occur during the higher rev range, but if revs are dropped or a gear change is made the coolant light on dashboard will go out.

The water temp reading is never high and is always in normal range. The guys over here think it could be either the sensor in the coolant tank, or possibly a leak from rad cap.
Interesting. I noticed the same issue last week when I was driving at high revs for a few mins. As soon as you let the accelerator go the light goes off. Unfortunately I don't know if this is normal or not. Will be keeping attention to this thread.
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Old May 12, 2008 | 10:51 PM
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Wasn't there a TSB for this?
Check the bullentins on line here.
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Old May 13, 2008 | 12:51 AM
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I've noticed this problem too. I added more coolant and the problem hasn't returned
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Old May 13, 2008 | 08:28 AM
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This was happening to me the past few months, when I took my car in for the a oil change the service guy told me it was nothing more than a bad sensor.

However, to fix it they had to replace the coolant tank, because the sensor was attached to the tank. It spent the night in the shop so they could do that.

If the radiator light comes on for a few minutes at a time, and you can confirm there are no hose leaks, and the engine temp gauge remains stationary... then more than likely your problem is the sensor on the coolant tank. You can get it fixed via service bulletin like Razz1 said.

michael
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Old May 13, 2008 | 09:52 AM
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I had my coolant flushed a few weeks back with the FL22 type coolant. I have an 04 model so it didnt come standard with the newer coolant. The next day i noticed that during highway speeds in traffic, the coolant warning light had come on. The temp gauge was alright. I checked the reservoir, i saw that the coolant level was low. As the mazda service department was closed by the time the light had come on, I went to the local auto parts store and bought the store equivalent coolant to add.

A few weeks later while some doing some spirited driving, i noticed that the coolant light had come on again. Temperature was again ok...I pulled over and looked at the coolant reservoir and saw that it was over the full line. I didnt do anything...

A week later i got the coolant warning light while doing some spirited driving on the freeway. Temp ok.

The coolant light had never come on prior to the coolant flush at ~58k miles.

You guys think it's the coolant sensor or air still circulating in the system and bubbles hitting the sensor?

TJ
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Old May 13, 2008 | 10:04 AM
  #11  
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its a typical problem, the sensors are failing on alot of 8's there is another thread on this i think.
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Old May 13, 2008 | 11:00 AM
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The sensor is part of the coolant overflow bottle, its nothing but an *on/off* kind of switch, and its easy as hell to fail.

Just make SURE that your coolant level is fine, then u're good.

if you hate the light, either fix it at dealership under warranty, buy a new bottle replace it on ur own, or just ignore the light.
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Old May 13, 2008 | 12:11 PM
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mine has only done it when it was VERY COLD. I used to live in Iowa. Id start my car and it would idle at over 4K for a couple of minutes as the coolant light would stay on for a couple minutes.
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Old Jul 2, 2008 | 08:47 PM
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Same issue

I have the same issue. 2007 RX8 manual transmission.

After somewhat rapid acceleration to highway speeds (max rpm 6500-7000 rpm), then leveling off to around 4000 rpm in 5th gear, the light comes on after another 10 seconds or so.

Sometimes releasing the accelerator makes it go out. Sometimes to make it go out I have to upshift to 6th and sometimes I have to upshift to 6th and then wait 1-2 minutes.

I checked my coolant level and it's fine. My Mazda service station said it's a known problem of a wire not maintaining a good connection and there was a "sling" to support that bundle of wires. Sounded like bs to me, though they weren't going to charge me for it so I don't know why they'd bs. They never installed the "sling," and the light didn't come on for a while (maybe they tightened up something that was loose during the diagnosis?) Anyway, the problem has come back. I guess I'll tell them other folks have had problems with the coolant sensor.

Once this behavior is triggered by rapid acceleration, I don't even have to be moving. Simply revving to 3700-4000 rpm for 5 seconds or so brings the light on. Releasing the accelerator turns it off. After the car has been off for a while, though, driving at 4000 rpm for a bit *without accelerating rapidly first* won't bring the light on. Weird.

The temperature gauge is rock steady throughout it all, and I've never noticed a low coolant level.
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Old Jul 3, 2008 | 01:46 PM
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Hi

Just a quick update, I too recently took my car to my local dealer for this ongoing saga. They had my car for a day trying to find any problems relating to the coolant light.

I was informed no faults were evident and my service invoice reads, quote " checked over vehicle for coolant light on. No fault found. It is due to the water pump piling the water through the system, which makes the water level get lower" the general thought over here is that Mazda are clueless of this problem, as many of us are encountering it, and as yet there is no sure fix.

As for my car, the light is still staying on, and some three weeks ago i did a trip of some 500 miles, the best part of this was with the light being on. I do always check the levels, and the temp needle is always in the normal zone.

Although im not overly worried with the light staying on, my major concern is what if something does happen, not connected to this problem, I:E a radiator leak. After getting use to it been on, you have no way of knowing if its a warning for something else!!

It would be interesting to see if Mazda are planning a recall to rectify this fault, as yet us guys over here are still been left in the dark.

Nige
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Old Nov 20, 2009 | 04:01 AM
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i have the same problem as well. the temp level is ok. whats the best solution.?
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Old Nov 20, 2009 | 06:16 AM
  #17  
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Originally Posted by nycgps
the sensor is part of the coolant overflow bottle, its nothing but an *on/off* kind of switch, and its easy as hell to fail.

Just make sure that your coolant level is fine, then u're good.

if you hate the light, either fix it at dealership under warranty, buy a new bottle replace it on ur own, or just ignore the light.
...3 posts later...

Originally Posted by ronn111
i have the same problem as well. The temp level is ok. whats the best solution.?
Read dude
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Old Nov 20, 2009 | 12:49 PM
  #18  
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wow i read this then realized it's a revival
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Old Nov 20, 2009 | 01:09 PM
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Search!!!!!!!!!!!

It's and old subject covered many, many times......it's the sensor.

Last edited by Mazurfer; Nov 20, 2009 at 07:52 PM.
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Old Nov 20, 2009 | 05:02 PM
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Someone can't read.
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Old May 19, 2011 | 05:59 PM
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Does anyone know what the average cost is to have the coolant tank and sensor replaced?
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Old May 19, 2011 | 09:48 PM
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I got a quote of 250 for it to be replaced.. it has to be the entire tank because the sensor comes with it already. There is no way of just changing the sensor
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Old May 19, 2011 | 09:59 PM
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Thread bump...2 years!
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Old May 20, 2011 | 12:23 AM
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If you're really that **** about it, sure get it replaced. Otherwise disconnect the sensor and lights gone.
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Old May 20, 2011 | 12:29 AM
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But if u do disconnect the sensore make sure u check ur coolant often or else goodbye engine
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