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Hi, I've a 97MY 9000 anniversary. The temp gauge was sitting low and then dropping to very low or zero during driving. I changed the temp sensor on the side of the engine and that sorted it for a couple of days, but now the temp gauge sits just above the blue cold line when the engine is hot - then sometimes literally jumps up to normal, then back to just above the cold. I've noticed that the fuel gauge jumps up in sympathy at the same time. I suspect the fuel gauge is reading low too, since the EDU says I've got 300 miles range left with only a quarter tank of fuel... Not possible unless the engine has suddenly morphed into a 1.1 diesel!
Any help much appreciated. I'm guessing now I've got a problem with the gauges rather than the temp sensor....
 

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Low readings on the temp gauge normally point to a duff thermostat or a temperature sender going. But when taken in conjunction with the fuel gauge strangeness, you appear to have a power supply / earth issue into the instrument cluster. Search the forum for instrument cluster or taking the dash top off and there are some helpful posts on the subject.

Given the nuisance factor, I'd do the thermostat first to eliminate it. Your fuel gauge could be a separate issue.
 

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cbarrow,

This could be a number of things. If we believe that the problems are linked then I'd start looking for a poor earth conection around the instrument binnacle or perhaps a loose edge connection on the circuit boards thereon. Either requires the top of the dash to be removed. Do a search to identify where all the hidden fixings are and don't drop the 5mm washer up near the speaker on the driver's side.

Next. The temperature gauges are well known for erratic behaviour. It stems from the design which inputs the measured value from the sensor to the ecu which then outputs what it thinks you need to know. In other words, it sits moore or less in the middle unless things go seriously wrong when it swings widely so that you notice it. Looks to me like you have a failed thermostat.

The fuel gauge could be a poor connection at the tank ( there is an inspection hatch in the boot under the floor) or have you checked that the setting is giving you mpg rather than litres per 100km.

Paul @ Kippen.
 

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thanks guys. Will try changing the thermostat first.
The temp gauge in my 1995 9000 creaps up a little, then falls down to nothing. This is repeated a few times on a long journey. Just had the thermostat renewed, but didn't change the behaviour of the temperature gauge. Can it be fixed? The rev counter also comes on and goes but don't care so much. The temp gauge is essential.
 

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Yes the fact that temp gauge suddenly falls down to nothing suggests an electrical problem. But has anyone else been able to see this and fix it? Is the temp gauge mechanism different from the rev counter? In contrast, the rev counter seems to "wake up" after 20 miles or so, then stay on and not falling down.
 
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