Temp Gauge always cold with moving
23 September 2010 | 04:46 PM
#1
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Temp Gauge always cold with moving
Hi
The the title says my water temp gauge only works when the car is stopped in traffic. as soon as you start to move it goes back down to nothing.
its just had the system flushed and new thermostat put in it to try fix the problem.
any ideas apart from the gauge has gone faultly???
(heaters are hot)
The the title says my water temp gauge only works when the car is stopped in traffic. as soon as you start to move it goes back down to nothing.
its just had the system flushed and new thermostat put in it to try fix the problem.
any ideas apart from the gauge has gone faultly???
(heaters are hot)
23 September 2010 | 05:07 PM
#2
It could be the sender, the gauge, or the wiring.
I assume you've done the obvious like checked that the heater blows hot air? And that the hoses are both hot? If so, I'd check the wiring to the sender first, could easily be an itermittant earth fault. Then try a know working sender and finally look at the gauge.
However, if the heater isn't blowing hot and the hoses aren't hot, it's more likely to be an airlock, or blockage, or even the water pump on it's way out, with the impellor only actually turning when engine revs rise.
I assume you've done the obvious like checked that the heater blows hot air? And that the hoses are both hot? If so, I'd check the wiring to the sender first, could easily be an itermittant earth fault. Then try a know working sender and finally look at the gauge.
However, if the heater isn't blowing hot and the hoses aren't hot, it's more likely to be an airlock, or blockage, or even the water pump on it's way out, with the impellor only actually turning when engine revs rise.
23 September 2010 | 05:25 PM
#3
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Strange, the temp guage going down when driving is usually a sure sign the thromstat is sticking open.
I suppose the new one could be faulty (afterall, its only a lump of wax in a brass bulb). Either that or a bad wire is making and breaking contact whilst driving.
I would get my laser thermometer out and go probing first though (paying attention to the temps of heater hoses, radiator pipes and theromostat housing).
I suppose the new one could be faulty (afterall, its only a lump of wax in a brass bulb). Either that or a bad wire is making and breaking contact whilst driving.
I would get my laser thermometer out and go probing first though (paying attention to the temps of heater hoses, radiator pipes and theromostat housing).
Last edited by ALi-B; 23 September 2010 at 05:27 PM.
23 September 2010 | 07:12 PM
#4
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Scooby Newbie
Joined: Jun 2010
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thank you but i have a slight update.
took it out tonight and left it sitting before i drove off and checked the heater and it was nice and warm with the gauge sat in the middle.
drove along the road and the gauge went right down the bottom showing stone cold and the heater was also blowing cold (or very slight warm) stopped at the petrol station and the temp gauge went to normal, the fans cut in and the heater was blowing cold.
noticed though! the little pipe at the top left of the radiator that goes back into the header tank is missing - there's a blot in each end blocking them off.
this is the first time i've driven the car because when i picked it up it was doing this. thermostat and water pump have all been changed. what does that little pipe do and do you think thats where my problem may be?
car is a MY94 WRX
thank you in advance
took it out tonight and left it sitting before i drove off and checked the heater and it was nice and warm with the gauge sat in the middle.
drove along the road and the gauge went right down the bottom showing stone cold and the heater was also blowing cold (or very slight warm) stopped at the petrol station and the temp gauge went to normal, the fans cut in and the heater was blowing cold.
noticed though! the little pipe at the top left of the radiator that goes back into the header tank is missing - there's a blot in each end blocking them off.
this is the first time i've driven the car because when i picked it up it was doing this. thermostat and water pump have all been changed. what does that little pipe do and do you think thats where my problem may be?
car is a MY94 WRX
thank you in advance
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