205 Xs - Temperature Gauge Broken?

[conor2469 0]

Hi guys,

 

I just bought a 1991 205 XS 1.4 tu3s. the water temp needle does not sit back down on its rest. It stays about 1/5 way up the gauge. This is without any key in the ignition and the car is stone cold. The fuel gauge and rev counter both seem to work fine.

When I turn on the car the temp gauge climbs quite quickly and goes up to max after about 30 seconds.

 

I suspected a dodgy sensor but when I unplug the sensor the gauge falls back down to 1/5 on the gauge and stays there, it refuses to go back to 0!

Are the temperature gauges in XS dashes prone to this?

 

Also the thermostat is working fine and the car is full of coolant and is bled.

[And 15 1 Cars]

I use mine as a oil temp some times it stays up but a tap on the top off the dash and it drops back, only dose it now and then tho but it's a stage car so don't get much use any way.

[conor2469 0]

Thanks for the info. This car has been lying up for some time, I say the needle is sticky or something. I might try and dismantle the binnacle to free it up. Its quite unnerving starting and running a car that hasn't been driven in a long time and not having an accurate coolant temp gauge.

[jackherer 543]

If you unplug the sensor then touch the wire to ground the gauge will go to maximum, it might be worth doing that a few times to see if that frees it off and returns it to zero.

[conor2469 0]

If you unplug the sensor then touch the wire to ground the gauge will go to maximum, it might be worth doing that a few times to see if that frees it off and returns it to zero.

 

Good idea, I will give that one a try!

[conor2469 0]

Bit of an update. with the car off the needle now sits on the lowest white line on the gauge. I assume this is as far back as it can go?

I have flushed out the radiator and it was perfect. I tested the thermostat and it opens. I refilled and bled the car. The fan switch isn't working so I have the high speed fan wired to run continuously. With the fan running continuously the gauge sits at 3/4 up the gauge. Surely the gauge is wrong?

 

There is only one temp sensor on the thermostat, a red one. Should there not be two sensors, one for the temperature gauge and one for the warning light?

[trogboy 17]

Where does it sit when you ground out the sensor wire to earth?

[conor2469 0]

The gauge will max out if I ground the wire to earth

[conor2469 0]

I took the dash binnacle out, I think the temperature gauge is broken. when I tilt the clocks to one side the needle lops over, when I tilt it back the other way the needle swings back. It seems to be loose and not properly held by whatever moves it. If I get a set of donor GTi dials will the temperature gauge transfer over to the XS binnacle?

[toolie72 67 1 Cars]

You can move most gauges with your finger with very little resistance so that's not really a test-it's internal electrical resistance

I suppose if you were careful you could let car get up to temperature, switch off, slowly open cap and stick a cooking thermometer in the tank-if temp is per spec then you know it's gauge-if temps too high you know you have another problem and gauge is ok

 

Don't know about swapping gauge sets in the 205, I did it in a talbot sunbeam and used about a metre of cable, soldering iron etc, so doable but have both circuit diagrams side by side-most looms are the same between models it's just the ittybitty faff

[conor2469 0]

You can move most gauges with your finger with very little resistance so that's not really a test-it's internal electrical resistance

I suppose if you were careful you could let car get up to temperature, switch off, slowly open cap and stick a cooking thermometer in the tank-if temp is per spec then you know it's gauge-if temps too high you know you have another problem and gauge is ok

 

Don't know about swapping gauge sets in the 205, I did it in a talbot sunbeam and used about a metre of cable, soldering iron etc, so doable but have both circuit diagrams side by side-most looms are the same between models it's just the ittybitty faff

 

 

Ah I see. I figured it would operate under much the same principle as the fuel level gauge. The fuel level gauge didn't budge when I moved the gauge from side to side.

I will try your trick with the kitchen thermometer.

[conor2469 0]

Just to put some closure to this issue, it turns out the temperature gauge was broken. I fitted an additional temperature gauge and the coolant temperature is perfect. Mystery solved.