Pessimistic fuel/temp gauge

[Lap]

Hi all,

Have a 1989 8V Digi. The water temperature gauge never moves more than a 1/4 of the way across (ie just to the end of the solid white bit). I've changed the sensor but its made no difference and I've put in a new fan switch and seen the fan come on and all the hoses get hot etc.

In addition to this, the fuel gauge never indicates full. It doesn't quite get to the full end stop. So when you are 'low' on fuel and the gauge is well into the red and you are driving along wondering when you will run out of fuel, you find you can only put about 30 litres into it which means it could have done another 150 miles! 

So my theory is that both gauges are under reading. The question is, why? Thanks for any help.

[T_J_G]

Hi all,

Have a 1989 8V Digi. The water temperature gauge never moves more than a 1/4 of the way across (ie just to the end of the solid white bit). I've changed the sensor but its made no difference and I've put in a new fan switch and seen the fan come on and all the hoses get hot etc.

Mine did that and it was dodgy thermostat. If the lower rad hose gets hot very quickly from a cold start the thermostat is knackered.

[russ-vdub]

i had that problem for a while but it went away.. i had a feeling it was something to do with the wiring.. check the haynes and ake sure all the connections are solid (meaning free from crap and not loose)

[8vRicey]

Hi all,

Have a 1989 8V Digi. The water temperature gauge never moves more than a 1/4 of the way across (ie just to the end of the solid white bit). I've changed the sensor but its made no difference and I've put in a new fan switch and seen the fan come on and all the hoses get hot etc.

Mine did that and it was dodgy thermostat. If the lower rad hose gets hot very quickly from a cold start the thermostat is knackered.

Second that.

[Lap]

Cheers. I'll definitely be checking the wiring for the instruments.

As for the thermostat, I had it changed a while ago and there was no difference before and after. I have checked all the usual things and I am sure the engine is running to temperature. I think the gauges are misreporting it.  

[T_J_G]

Cheers. I'll definitely be checking the wiring for the instruments.

As for the thermostat, I had it changed a while ago and there was no difference before and after. I have checked all the usual things and I am sure the engine is running to temperature. I think the gauges are misreporting it.  

i changed it once and it stayed the same. did it again and voila. Though as you say it may be the gauges but at roughly a tenner for thermostat it'd be stupid not to rule it out?