Technical Two issues : Fuel and Temp

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Technical Two issues : Fuel and Temp


Jun 17, 2020
Not really sure if they're issues or I just don't understand how the car works.

So I've got dashed lines, but my fuel gauge is above the empty bar, occasionally I see the dashed lines appear when I'm not moving, what are the dashed lines doing exactly? I feel as if the fuel pumps not working correctly or theres an issue with the wiring. I personally want to change the fuel pump because I feel like it's incorrectly telling me my fuels low, at times I'm hitting the bottom of the red bar and (Correct me if I'm wrong) I was told when you're low on fuel you can see your emissions smoke increase? and I never see that.

Regarding the temperature, I was doing 77mph, occasionally hit 80, due to going down hill and only realising when looking at the speed odometer and I noticed my temperature bar was going down, and it was quite a hot day, though once going back to 50-60 the temp would go back to the correct position, is this normal? I've changed the thermostat (green thing) a few months back and the problem was it struggled to get up to the half mark but since changing it's been fine, just noticed the 80mph issue the other day though.

I've ran a OBD II scan and the other scanner type, only came across air bag issues which I will be taking the car apart tomorrow and checking the airbag unit to see if it's just a lose wire or somethings gone bust, but I've seen no issues with fuel nor thermostat, can anyone advise me on what to do about the fuel and if the temperature going down at high speeds is normal?



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Hi, normally those dashed lines appear when you reset the tripmeter and you have selected the fuel economy display with the tripmeter button. After a few hundred metres the dashed lines are replaced by numbers indicating estimated fuel economy. If it is resetting randomly that would more likely be a bad earth than a faulty sensor (wheel speed or fuel flow). 'Green thing' sounds like you replaced the coolant sensor. The thermostat is part of the aluminium housing that is bolted to the end of the engine near that sensor. It is where the rubber radiator hose connects. Your temp problem sounds like what happens when a thermostat is stuck open.
Changed the thermostat, it seems like it may have been stuck as the copper rod inside was poking out quite far, compared to the replacement one I bought. Also it seems the gasket around it had corroded pretty badly.

The temp is sitting at half way now, rather than just a tiny bit below, someone suggested this may be to do with the oil being a bit low? My oils just below the halfway mark, would this be the problem?