What does your temp gauge read???
Discussion
Since buyig my MX-5 about a month ago, I've always been concerned where my temp gauge sits at normal running temp. On mine it sits between the middle and max, it stays there and doesn't move. I've read that other peoples' sits about halfway which is where I would expect it to.
Is this something I should be concerned about, or is it normal? I've recently done a coolant flush and change, but its the same before and after....???? Where does the needle sit on other peoples temp gauge?
Is this something I should be concerned about, or is it normal? I've recently done a coolant flush and change, but its the same before and after....???? Where does the needle sit on other peoples temp gauge?
Edited by FELIX_5 on Tuesday 2nd December 11:02
It's a non linear gauge, so really only starts to move when temperatures are seriously high. As long as your fans are operational and you are not losing coolant you have nothing to worry about.
I have an ecu that measures coolant temperature, yet the guage doesn't move even when coolant temperature is 100C - from 70-100C no movement of the gauge, so unless yours start to move to the right dont worry...be happy
I have an ecu that measures coolant temperature, yet the guage doesn't move even when coolant temperature is 100C - from 70-100C no movement of the gauge, so unless yours start to move to the right dont worry...be happy
How much Anti-freeze did you use as the cheap stuff mixes at 50% and quality stuff at a third, if you have not got enough the engine will run hot.
Forgive me if you know this.
Secondly have you tried the connection to the sensor as it may have oxidised and may be giving a false reading.
Forgive me if you know this.
Secondly have you tried the connection to the sensor as it may have oxidised and may be giving a false reading.
freerange7 said:
How much Anti-freeze did you use as the cheap stuff mixes at 50% and quality stuff at a third, if you have not got enough the engine will run hot.
Forgive me if you know this.
Secondly have you tried the connection to the sensor as it may have oxidised and may be giving a false reading.
It has the correct amount of anti-freeze, but haven't checked the connection to the sensor. Judging by your response is this not a normal reading then? (Not being funny) Forgive me if you know this.
Secondly have you tried the connection to the sensor as it may have oxidised and may be giving a false reading.
Does seem a little high.
Most of our customers are looking at the price of the antifreeze and they are oblivious to the fact there are three basic colours, some do not mix and unaware that it a certain percentage is required and it also acts as a cooling product.
The wrong antifreeze will also contribute to head gasket failure.
On Fords the oil temp sensor has a very basic connection and as it oxidises it can give the wrong reading, not sure what the connection for Mazda is like, this maybe similar giving you a high water temperature reading, if the engine does not feel hot and the hoses are OK, I would look in that direction.
Most of our customers are looking at the price of the antifreeze and they are oblivious to the fact there are three basic colours, some do not mix and unaware that it a certain percentage is required and it also acts as a cooling product.
The wrong antifreeze will also contribute to head gasket failure.
On Fords the oil temp sensor has a very basic connection and as it oxidises it can give the wrong reading, not sure what the connection for Mazda is like, this maybe similar giving you a high water temperature reading, if the engine does not feel hot and the hoses are OK, I would look in that direction.
freerange7 said:
How much Anti-freeze did you use ... if you have not got enough the engine will run hot.
Not sure that's right - water alone is the best at heat dissipation, a water/anti-freeze mix will have a lower ability to remove heat but you need the antifreeze to a)stop it freezing(!) , b) to inhibit rust forming, and c)it raises the boiling point of the mix.Right chaps.
Don't mix anti freeze, and if you do change flush it properly. I didn't, and I can vouch that mixing the magic pink and blue gives blancmange, although the taste is a bit bitter. I stick with the blue stuff these days - the age of the car means coolant is in and out of it* often enough to make the longer life stuff pointless
(* for rad changes, head gasket replacement, split hoses etc.)
You won't change the temperature of running (appreicably) with varying proportions of anti freeze. I know about the raising the boiling point, and actually, academically, this can help by stopping coolant evaporation where it meets the head - this can cause a gas layer to build up and will reduce heat transfer from the combustion chamber into the coolant.
The gauge is not calibrated, and it seems with the MX5 there was a policy of making the gauges 'look right' in most circumstances, e.g. non linear temp gauge and on later cars, the 'on off' oil pressure gauge. I wouldn't make subtle judgements based on the gauge reading, uless of course it does move over significantly to the right. Does the car exhibit overheating? Does the gauge actually move more than a couple of mm when the car is in traffic or under load (e.g. motorway speeds)? Is there any coolant loss? If not then there is unlikely to be anything to worry about.
Obviously typical problems are sludged up radiators/non working fans if you do have any symptoms, I won't mention any others yet because it'll just make you paranoid.
Don't mix anti freeze, and if you do change flush it properly. I didn't, and I can vouch that mixing the magic pink and blue gives blancmange, although the taste is a bit bitter. I stick with the blue stuff these days - the age of the car means coolant is in and out of it* often enough to make the longer life stuff pointless
(* for rad changes, head gasket replacement, split hoses etc.)
You won't change the temperature of running (appreicably) with varying proportions of anti freeze. I know about the raising the boiling point, and actually, academically, this can help by stopping coolant evaporation where it meets the head - this can cause a gas layer to build up and will reduce heat transfer from the combustion chamber into the coolant.
The gauge is not calibrated, and it seems with the MX5 there was a policy of making the gauges 'look right' in most circumstances, e.g. non linear temp gauge and on later cars, the 'on off' oil pressure gauge. I wouldn't make subtle judgements based on the gauge reading, uless of course it does move over significantly to the right. Does the car exhibit overheating? Does the gauge actually move more than a couple of mm when the car is in traffic or under load (e.g. motorway speeds)? Is there any coolant loss? If not then there is unlikely to be anything to worry about.
Obviously typical problems are sludged up radiators/non working fans if you do have any symptoms, I won't mention any others yet because it'll just make you paranoid.
franv8 said:
Right chaps.
Don't mix anti freeze, and if you do change flush it properly. I didn't, and I can vouch that mixing the magic pink and blue gives blancmange, although the taste is a bit bitter. I stick with the blue stuff these days - the age of the car means coolant is in and out of it* often enough to make the longer life stuff pointless
(* for rad changes, head gasket replacement, split hoses etc.)
You won't change the temperature of running (appreicably) with varying proportions of anti freeze. I know about the raising the boiling point, and actually, academically, this can help by stopping coolant evaporation where it meets the head - this can cause a gas layer to build up and will reduce heat transfer from the combustion chamber into the coolant.
The gauge is not calibrated, and it seems with the MX5 there was a policy of making the gauges 'look right' in most circumstances, e.g. non linear temp gauge and on later cars, the 'on off' oil pressure gauge. I wouldn't make subtle judgements based on the gauge reading, uless of course it does move over significantly to the right. Does the car exhibit overheating? Does the gauge actually move more than a couple of mm when the car is in traffic or under load (e.g. motorway speeds)? Is there any coolant loss? If not then there is unlikely to be anything to worry about.
Obviously typical problems are sludged up radiators/non working fans if you do have any symptoms, I won't mention any others yet because it'll just make you paranoid.
A very good point and well made. I recently changed the coolant and flushed the system. After much deliberation on which anti-freeze to use I went for the green stuff. It doesn't overheat, nor does the needle move when in traffic, the fan kicks in as it should and there is no sign of coolant leaks. Its probably me being paranoid, as you rightly say. Just want the car to be in tip top condition. This is the first car I've had where the temp gauge hasn't sat at the halfway mark. Hopefully its nothing to worry about, although would have been nice if I'd had loads of responses sayin "mine is exactly the same, don't worry"...... Don't mix anti freeze, and if you do change flush it properly. I didn't, and I can vouch that mixing the magic pink and blue gives blancmange, although the taste is a bit bitter. I stick with the blue stuff these days - the age of the car means coolant is in and out of it* often enough to make the longer life stuff pointless
(* for rad changes, head gasket replacement, split hoses etc.)
You won't change the temperature of running (appreicably) with varying proportions of anti freeze. I know about the raising the boiling point, and actually, academically, this can help by stopping coolant evaporation where it meets the head - this can cause a gas layer to build up and will reduce heat transfer from the combustion chamber into the coolant.
The gauge is not calibrated, and it seems with the MX5 there was a policy of making the gauges 'look right' in most circumstances, e.g. non linear temp gauge and on later cars, the 'on off' oil pressure gauge. I wouldn't make subtle judgements based on the gauge reading, uless of course it does move over significantly to the right. Does the car exhibit overheating? Does the gauge actually move more than a couple of mm when the car is in traffic or under load (e.g. motorway speeds)? Is there any coolant loss? If not then there is unlikely to be anything to worry about.
Obviously typical problems are sludged up radiators/non working fans if you do have any symptoms, I won't mention any others yet because it'll just make you paranoid.
FELIX_5 said:
A very good point and well made. I recently changed the coolant and flushed the system. After much deliberation on which anti-freeze to use I went for the green stuff. It doesn't overheat, nor does the needle move when in traffic, the fan kicks in as it should and there is no sign of coolant leaks. Its probably me being paranoid, as you rightly say. Just want the car to be in tip top condition. This is the first car I've had where the temp gauge hasn't sat at the halfway mark. Hopefully its nothing to worry about, although would have been nice if I'd had loads of responses sayin "mine is exactly the same, don't worry"......
The main issue Felix, is that the gauge is not linear, so regadrless of it's postion you don't actually know the ACTUAL temperature of the coolant. If the guage doesn't move during normal driving and the fans kick in as they should there really shouldn't be a problem to worry about. One other test that you can try is to operate the 2nd fan (A/C fan if you have one) this can be done by depressing the A/C button and switching on the heater fan. If the guage starts to move to left with this operation then the issue may be that it is running slightly hot. If the gauge doesn't change then you dont have a problem that I can determine. One other test that you can try is to operate the 2nd fan (A/C fan if you have one) this can be done by depressing the A/C button and switching on the heater fan. If the guage starts to move to left with this operation then the issue may be that it is running slightly hot
I'll try that, thanks for the tip.....!
I'll try that, thanks for the tip.....!
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