How Hot?

[DaisyMayFozz]

Hi,
We have noticed recently that when driving the morris the temp guage reads 3/4 not 1/2, Is this normal? If not what is the problem. we have a smiths temp guage that was fitted when we bought the car. Could this be the fault?
Thanks

[kittyfell]

Hopefully it's a gAUge, and yes that could be 'normal' if a winter rated thermostat has been fitted. Does the heater work well?

[MarkyB]

Can you ask the previous owner what is "normal"?
What happens if you get stuck in traffic for 10 minutes or so?
If it doesn't go into the red it should be fine, but it may be the sender and gauge aren't a proper match.

[mike.perry]

Is it a capillery or electric temperature gauge? If it is an electric gauge then have you connected it through the voltage stabiliser on the back of the speedo on a 1098. Earlier cars did not have a v/s. The Smiths electric gauge is designed to run on the 10V delivered by the output terminal of the stabiliser, the same terminal that connects to the fuel gauge. 12v will cause the temp gauge to over read.

[DaisyMayFozz]

thanks for the quick reply, We think that it is a electric gauge, by normal we mean 1/2 'N' on our gauge once the engine heated up. On mordern cars it is normally 1/2 once heated up. we have only had the car for 10 months and have not yet found out what thermostat she has. At some point one of the cars 4 previous owners has fitted a 1098 engine,gearbox,and speedo, heater and various other things. this is our gauge:[frame][/frame] the picture is a bit blurred, quicky done 5 mins ago. also yes the heater works well, after 10 mins in traffic it goes to 'H' Hot. thanks for the help

[mike.perry]

That is an electric gauge which does what it says, cold, normal, hot which is about as precise as it gets.
You should have one wire from the voltage stabaliser to the gauge and another from the gauge to the sensor in the cylinder head below the thermostat. The other wire is the backlight.

[katy]

Have you checked the coolant level in the radiator?

[DaisyMayFozz]

yes, checked it after we noticed that it was reading a bit high and it had plenty of coolant in the radiator.
thanks

[Declan_Burns]

Has it always been like that? Assuming your cooling system is working OK and the gauge is connected correctly as mentioned above, then it might just need to be calibrated. Last weekend, I replaced exactly the same gauge with a gauge reading 40 ... 140°C, which read about 2/3 scale when warm as opposed to the old gauge reading "N", and had to re- calibrate it-see photo.
It required adding a series resistor ~10 ohm to bring it down to read 90°C .
If you want to be very accurate, you can use a potentiometer 0 ... 47 ohms (a few pence at an electronics shop) and adjust it to read exactly at "N". A cross-check with the coolant temperature in the rad will do no harm as I think it's only a few degrees off the temperature measured at the head and more than sufficient for your gauge. Be carefull opening the rad cap!

Old gauge[frame][/frame]
New gauge which read high on installation[frame][/frame]

Another, but more expensive option, is to replace the sensor. The part no. from Intermotor for your gauge is 5271.

Hope this helps

[newagetraveller]

So long as your engine is not getting so hot that your radiator is boiling over and you are continually having to top it up I would not worry about it.

[DaisyMayFozz]

thanks for all the replies, you have been very helpful (once again). we will work to all your replies to try and solve the problem. once again it is a very usefull site.
thanks

[bmcecosse]

It's almost certainly the voltage stabiliser problem. ie - It's connected directly and NOT through the stabiliser.