Temp Gauge range

[Dave M]

I have fitted a capillary tempgauge and wondered how the readings Im getting would compare with the traditional electric gauge.

What temp does the quarter, halfway and red area of the gauge equate to?

My Stag appears to be runningbetween 60 deg C and 90 deg C dependant on ambient temp etc.

The 60 deg reading only tends to happen on a chilly morning when driving on the motorway at say 60-70 mph, seems a bit low to me and Im now wondering if the gaugeis in fact reading low, is the 90 deg reading also low, hence the above question.


Dave

[Thurlo Squire]

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Where's the sensor fitted Dave? I tested mine by boiling the kettle and dropping the sensor in as it was boiling. Seemed to be quite a good way of testing it.

Nigel

[Dave M]

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Hi Nigel

Sensor is mounted where the electrical one is normally fitted, will try the boiling water test the next time I drop the coolant.

I am currently running on 100% antifreeze any thought on this?


Dave

[GDPR]

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Plenty! Raw antifreeze is a rotten coolant. Run at 30% max.

Have you got a thermostat in it?

[stustag]

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Hi Dave

You need to be running 33% antifreeze with DISTILLED water, make sure you have the correct thermostat fitted as well (as per Kryten)

I run 33% antifreeze, yesterday did 194 miles and raced up Prescott twice temp guage never went above halfway all day (20 C Air Temp)

Stuart

[Thurlo Squire]

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Dave, my capillary gauge tends to run around the 80/90 degrees mark which is around halfway on the standard gauge which is still fitted. However my capillary sensor is mounted in the top of the radiator which will be slightly cooler than the standard position I guess.

I would say 60 degrees is too cool but like the others have said I would certainly change your coolant if you are running neat. At the same time test the thermostat and the gauge by boiling the water in a pan with your thermostat and gauge sensor in it and then you should able to see the 'stat open at around 82 degrees.


Nigel

[Marco Polo]

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stustag wrote:

I run 33% antifreeze, yesterday did 194 miles and raced up Prescott twice temp gauge never went above halfway all day (20 C Air Temp)

Stuart

20C !!!!! That's a heat wave over there isn't it? Old ladies will be feinting all over the place! You will have drought conditions by June. (Only got to 26C here today)

[Dave M]

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Yea I knew the 100% antifreeze was wrong but was hoping it would show up any leaks since the core plug blowout. Even with the 100% antifreeze the car still appears to be running realy cool, 60 deg C with a maximum of 90 deg C. Unusual to hear of anyone complaining about a cool running Stag I guess but just worried in case the gauge is reading low.

Will drop some antifreeze and top up with distilled water. Oh yea thermostat is fitted, can not remember rating but it does have bypass hole in it.

Also Mk 11 running on 15lb cap, been like that since engine rebuild at Wards.



Dave

[Sheepdip]

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Dave, my Smiths dual gauge fitted in LH head reads a fraction over 80 going to 90 on cooldown from fast run in recent daytime temperatures. Stat is 82 so I reckon this is all ok.

I refitted a sender (not the one I removed for reasons) to RH head and gauge reads just below N at 80 deg, however the probe is not fully in the water flow so may not be accurate.

Was your capillary gauge new? Does the sensor fully enter the transfer housing? I also suggest removing and testing stat - I've had many stats fail by opening early on several cars, usually shows by cool heater.

Paul

[Guest]

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Sheepdip wrote:

Dave, my Smiths dual gauge fitted in LH head reads a fraction over 80 going to 90 on cooldown from fast run in recent daytime temperatures. Stat is 82 so I reckon this is all ok.

I refitted a sender (not the one I removed for reasons) to RH head and gauge reads just below N at 80 deg, however the probe is not fully in the water flow so may not be accurate.

Was your capillary gauge new? Does the sensor fully enter the transfer housing? I also suggest removing and testing stat - I've had many stats fail by opening early on several cars, usually shows by cool heater.

Paul

Go on, splash out on a new stat, their about 7p, not worth testing. 82 or 88 doesn't make much difference in a Stag, they never get cool enough to close it anyway and the opening points are so close itdoesn't really matter. If you have a Mk 2 enginejust make sure you get thestat with the foot. Martin.

[Dave M]

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Sheepdip wrote:

Dave, my Smiths dual gauge fitted in LH head reads a fraction over 80 going to 90 on cooldown from fast run in recent daytime temperatures. Stat is 82 so I reckon this is  all ok.

I refitted a sender (not the one I removed for reasons) to RH head and gauge reads just below N at 80 deg, however the probe is not fully in the water flow so may not be accurate.

Was your capillary gauge new? Does the sensor fully enter the transfer housing? I also suggest removing and testing stat - I've had many stats fail by opening early on several cars, usually shows by cool heater.

Paul

Hi Paul
Capillary gauge was new but due to having to use an adaptor I dont think the sensor protudes that far into the transfer housing but as long as its immersed in coolant it should read the temp of the coolant passing through the transfer housing, shouldnt it?
Im probably worrying over nothing but unfortunately thats the way it is with my Stag at the moment. Capillary gauge was fitted when Wards rebuilt the engine 10 years ago and its always read low but since blowing out the core plug I have become a little more Stag paranoid. I have an 85deg fan switch mounted half way down the rad and to be honest the fan never runs.
Question is, is it worth all the worry?

Dave

[Sheepdip]

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Hi Dave, I know what you mean about uncertainty, they're not cheap to repair when they go wrong. I think your temperatures are fine but personally I'd look at why it runs at 60, rather than gently fluctuating at 80 - 90 which I guess is around N on the gauge.

Paul

[Guest]

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Thurlo Squire wrote:

Where's the sensor fitted Dave? I tested mine by boiling the kettle and dropping the sensor in as it was boiling. Seemed to be quite a good way of testing it.

Nigel

That is the correct way of checking the sensor and gauge. Water boils at 100 degrees centigrade at sea level unless you live at the top of a mountain and even then it would only be a degree or two difference unless you live at the top of Everest. Place the sensor in a kettle of boiling water, keep the kettle lid open to stop it switching off and leave the sensor in the boiling water for at least 30 seconds. You can now look at the gauge and will know where 100 degrees is on the scale. Take care as boiling water on the skin will give you a sense of humour failure. If you wanted to get more readings on the gauge scale use a thermometer. Place the thermometer in the boiling water and take its reading. Assuming the thermometer is accurate it should read 100 degrees. If not i.e. it reads 98 degrees all you need to do is to add on 2 degrees on all your readings. So once you have the 100 degree reading switch off kettle and as it cools read off the thermometer and look at the gauge. You will now be able to see where the pointer on the gauge is relative to the temperature. This is known as transfer standards. I know there will be errors using this method but with the temperature range you will be reading the errors will not be noticeable. Sad I know this stuff, the joys of being a manager of a Calibration company.



Don Kennedy.

[Sheepdip]

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Don, this is the method I use for testing stats as well. I tried it with a new Kenlowe fan switch probe to check settings, with a pan on the electric stove. Don't know whether part of the capillary touched the hot plate or whether it was faulty but it failed to work. A kettle is a better idea!