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Discussion Starter #1
Heres a strange one hope anyone can help

Just aquired the car, basically when the car is started the temperature gauge needle jumps straight to red (even when cold start) then flicks back and forth continuously whilst driving (like a metronome) any ideas of a fix will be much appreciated:eek:

Thanks in advance
 

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I recently changed my thermostat [which came with a new temperature sensor in it] and on switching on the ignition, the exact same thing happened to mine! rather than change the thermostat again, I swapped over to the old sensor and everything was normal again!

I suspect a dodgy sensor!
 

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Discussion Starter #3
I recently changed my thermostat [which came with a new temperature sensor in it] and on switching on the ignition, the exact same thing happened to mine! rather than change the thermostat again, I swapped over to the old sensor and everything was normal again!

I suspect a dodgy sensor!
Thanks for your reply

I will check the temp sensor but would i need to change whole thermostat aswell or can you buy temp sensor alone.

all the best
 

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disconeect the sensors connetor as it might not be the sensor is defective but the gauge or the wiring loom.

yes, sensors can be bought seperately. :)
 

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Discussion Starter #5
disconeect the sensors connetor as it might not be the sensor is defective but the gauge or the wiring loom.

yes, sensors can be bought seperately. :)
Thanks for reply

will disconnect the sensor connector and check that out, but how could i test the wiring loom/Gauge without replacing.

All the best
 

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disconnect the sensor 1st, see what happens...wiring looms are a major pain to replace but very rarely required to do so.
 
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Wiring where it goes through the bulk head is a very common problem on 156's and can cause this issue as if the sensor is causing this the engine light should come on or the fans should cut in as it puts the overheat light on...
 

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Discussion Starter #8
Thanks for replies

Unplugged wiring from temp sensor problem still exists. I have no overheat light at all whilst driving, just when ignition is turned on (Self test) as with all the other dash lights. however i have noticed that when i accelerate the temp gauge becomes more erratic. could this be a earthing problem? Plus how do i test temp gauge to see if its the problem.

All the best
 

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Discussion Starter #12
Best I can come up with

http://i46.photobucket.com/albums/f112/monkeyrabit/Picture005-1.jpg

The red connector at the bottom of the pic in the middle attaches to a sender on the stat in a similar location. This is the sender for the engine management. The more crude looking 2 blade sender to the left under the main harnes is the sender for the temp gauge. HTH.
Hi Chris155 thanks for the pic
The connector i removed was the "crude looking 2 blade sender" which other sender do i remove as you say "Pre 2001 v6's have 2 temp senders"

All the best

Dave
 
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So you've replaced the temp sender for the guage then?

Other options:

Wiring fault
Broken guage
The temp readings are accurate....:eek:
 

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If you want to get your multimeter out the thermister (in the temp sender) should be about 600 Ohms when the car is cold and about 200 Ohms when the car is at about 90 deg ...
 

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High Hawky, I have a similar problem and am trying to fix it as well. Have you had any luck yet? So far I have replaced my radiator as initially I did no investigation and thought the readings could be correct, but my needle is now a little to erratic for me to believe that anymore! Next on my list is cleaning the sender connection
 

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Discussion Starter #17
So you've replaced the temp sender for the guage then?
Hi chris155
No just removed the sender connector still no joy.


Hi 156chris

Interesting thread was going to replace Gauge but reading this from the thread dont know if it will be worth while, quote biffa "in SEARs case he's used a gauge from a doner car which was working correctly when removed but not working when fitted to his car."
So will try multimeter see where i go from there.


High Hawky, I have a similar problem and am trying to fix it as well. Have you had any luck yet? So far I have replaced my radiator as initially I did no investigation and thought the readings could be correct, but my needle is now a little to erratic for me to believe that anymore! Next on my list is cleaning the sender connection
Hi Norseflyer;2631878

No Still no joy resorted to pulling the temp gauge needle out temporarily as it was really annoying, going to try multimeter reading see how it goes from there.

Thankyou all for replies

all the best
 
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^^-- link works fine for me :confused:
 
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