2021 Mazda 3 2.5 Temperature Gauge Reading

Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
Take a look at the temperature gauge on my sons 2021 Mazda 3 2.5 (non turbo). This was after a 25 minute drive into town with the outside temp around 40 degrees.
The air from the heater was coming out hot/normal for full heat. My son tells me when the outside temperature is warmer the temp gauge will make it to the middle position. Car performs flawlessly. Anyone out there with a similar model that can tell me if I should have this looked at or is this normal for Mazda's? Thanks.
temp.jpg
 

TCL

Joined
Nov 13, 2020
Messages
296
Was the motor running when this picture was taken, or was the key off?
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
Was the motor running when this picture was taken, or was the key off?
I believe it was on, but either way I watched it during the commute and right at the end with the engine running it was just like the picture. A few months ago when I did an oil change, I drove it a few block to warm the oil and the gauge did not move.
 
Joined
May 9, 2010
Messages
3,172
Location
Texas
The CX-5 has a coolant temp light and no gauge, so I can’t speak from experience. But after 25 min at 40 degrees, I’d expect to see it reading hotter than that.
 
Joined
Jul 7, 2014
Messages
3,504
Location
Winnipeg MB CA
Older Mazda temperature gauges typically sit just under "half" (say 7/16 of full scale) between about 75 and 95 C; your son's looks low to me.

I would plug a ScanGauge or equivalent into the port under the dash, to see what the ECU thinks the coolant temperature is - I say "thinks", because the sending unit for the gauge could be defective.

Mazdas247 may have a thread about this.

It should be under full warranty - I'd take it to the dealer regardless.
 
Joined
Nov 16, 2002
Messages
35,656
Location
NJ
When at full operating temp, it sits just under "half". It should not take long for it to reach that. Even when it's in the teens it will reach half in no more than 10 minutes.
 
Joined
Mar 4, 2017
Messages
24,847
Location
...
The CX-5 has a coolant temp light and no gauge, so I can’t speak from experience. But after 25 min at 40 degrees, I’d expect to see it reading hotter than that.


This might be model year dependent but you should be able to cycle through your info screen on the instrument panel and get the display that shows engine temperature.
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
I did call the service department and will bring it in. The person I spoke with did mention that the sending unit is probably the issue. If the heat coming out of the vents was not hot I'd suspect the thermostat, but it was hot. Like some said upstream, their advanced scan computer can probably test that circuit and diagnose real time. I'm gong to see if I can bring it in this Saturday at least for a diagnosis. I report back with what they find out.
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
This might be model year dependent but you should be able to cycle through your info screen on the instrument panel and get the display that shows engine temperature.
I'll check that out tonight. I don't driver this car so I'm not too familiar with the available readouts.
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
Any reasons on why there would not be a code thrown? Son says there have been no codes displayed on dash? Would a faulty engine coolant temp sensor normally cause a code?
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
Curious,
Does the gauge read ”normal” if you run the vehicle with the heater blower off?
No always in the cold area. Other driver does say it reaches normal operating temp when outside temps are warm. This is not my car so it's hard for me to see exactly what's happening all the time with the gauge. Bringing it to the dealer for a diagnosis this Saturday. My guess is ect sensor.
 
Joined
Feb 28, 2015
Messages
479
Location
MD
My 2017 6 with the 2.5 runs cool too. Not that cool, but always 1/3 or so on the gauge. I have very weak heat. I complained about jt, but the dealer pulled the BS about that’s a dummy gauge, that the scan tool shows normal operating temperature, and my heat is normal.

I did complain about quite a few other things all at once, so I think they took exactly zero of them seriously.
 
Joined
Jul 7, 2014
Messages
3,504
Location
Winnipeg MB CA
No always in the cold area. Other driver does say it reaches normal operating temp when outside temps are warm. This is not my car so it's hard for me to see exactly what's happening all the time with the gauge. Bringing it to the dealer for a diagnosis this Saturday. My guess is ect sensor.
I had exactly that experience with an '85 Mazda 626 - the thermostat got lazy, and I didn't think about it much until there was a mid-winter thaw and suddenly the gauge went up way closer to half than I was used to, and the cabin heat improved.

No surprise, a new thermostat fixed it.
 
Joined
Jul 7, 2014
Messages
3,504
Location
Winnipeg MB CA
My 2017 6 with the 2.5 runs cool too. Not that cool, but always 1/3 or so on the gauge. I have very weak heat. I complained about jt, but the dealer pulled the BS about that’s a dummy gauge, that the scan tool shows normal operating temperature, and my heat is normal.

I did complain about quite a few other things all at once, so I think they took exactly zero of them seriously.
I would get hold of a ScanGauge and see what the indicated coolant temperature is. The gauge is non-linear, but I'd bet that if the needle's only rising to about 1/3 of full scale, the coolant temperature will not be much over 50°C.
 

sohccammer427

Thread starter
Joined
Dec 11, 2006
Messages
456
Location
North Carolina, USA
Update from dealer. They said it was a defective water valve. I believe when I was young this was called the thermostat? Anyhwho, part ordered, only a two hour job per the T&L book. They also said it was not uncommon on this model. All is good. If I get the old part back I'll post a photo.
 
Joined
Apr 1, 2019
Messages
707
Location
Pennsylvania
Update from dealer. They said it was a defective water valve. I believe when I was young this was called the thermostat? Anyhwho, part ordered, only a two hour job per the T&L book. They also said it was not uncommon on this model. All is good. If I get the old part back I'll post a photo.
That engine doesnt have a thermostat per say. It has an electronically controlled coolant control valve. Under normal conditions the control valve controls coolant flow through 3 different cooling loops to control how fast the engine warms up and then regulates engine temperature. There is a mechanical fail safe thermostat in the control valve housing that only opens in the event of a significant overheat or control valve failure. Mazda has had some issues with those control valves and there is an updated part.
 
Top