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Faulty fuel gauge FIX (worked for me)

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44K views 41 replies 20 participants last post by  HattieBrooks  
#1 ·
Thought id post what i did to sort my fuel gauge out, when i brought the car about 6 weeks ago i noticed the day after the fuel gauge was not working correctly so after some searching the net i found the fuel gauge fault fell into 2 categories 1st where temp and fuel gauge move around at random a lot and the centre screen plays up and the 2nd where peoples fuel gauge and only the fuel gauge seems to just be out of sync where at empty it sits just under half and full shoots right off the top mine was like the 2nd type my fuel gauge was out of sync.

1st thing i did was remove the dash pod from the car but left it plugged in just pulled it forward enough to remove the front cover by removing the small torx screws once it was removed i gently pulled the needle off and then re positioned it ( i did this in the car park at the petrol station after filling up to the brim) at full then switched the ignition on and off few times, seemed ok but the more i turned it on and off the further round the needle shot until after a bout 10 times it was showing about quarter of a tank past full again.

This got me thinking and i noticed when you turn it on the needle shots round to full and you can here it hitting a stop of some sort and i thought maybe its this that is throwing it out moving it each time it hits so i pulled off the needle again turned the needle round and there is a little tab which i removed then reset the dial to full again by switching the ignition on and i know its full so just repositioned the needle at the full mark now when i switched the ignition on and the needle shots round it no longer hits a stop but when turning off the needle shots back and hits a clear piece of plastic that the full beam light shines through so i had to take a nick out of that too now turning the ignition on and off the needle hits nothing and as a result was staying accurate every time.

I then needed to modify the front cover too as the cylinder part that fits down round the gauge the walls would get in the way of the needle so the needle would hit the sides and knock it out again so i trimmed with a sharp knife both sides where it goes to empty and full so the needle can shot past the wall of the cylinder with no restrictions i then reassembled it that was 5 weeks ago and its been spot on since.

If you look at your fuel and temp gauge when you turn the ignition on the temp gauge moves to the start then moves to where the temp is but slowly and in a controlled manner and the fuel gauge moves to the start and the shots very quickly to where it sits but it goes so fast it over shots and springs back so I'm guessing it should be dampened like the temp gauge and as a result of it moving so quick and banging into its stop this is what is throwing it out of whack so by removing the stops it no longer bangs into anything and stays accurate.

Heres some pics i never took any while doing the job but heres some to show roughly what i did:

This shows how the gauge sits when the dash is in sleep mode:
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This shows the needle with the dash off resting out side the gauge:
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If you look closely you can see where i trimmed the back of the fascia so the needle can move behind it:
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And the same off the other side:
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Here's a link to a vid i made to show how the difference in the speed of the 2 needles(temp and fuel) and if you watch very carefully you can see it shot past where its meant to sit the spring back before i modified it you could here it hit the side of the fascia and now it shots out the gauge off the top and springs back to where it should be sitting, its hard to see because it moves so fast but if you look close;y enough you will see it:


Hopefully Ive explained it well enough but if there is any confusion let me know and ill try and explain it better, as i said this has permanently fixed mine and cost nothing but my dash was in full working order everything else is working perfectly it was just my fuel gauge sitting 1/2 a tank out, i dont think this will work for the people that are suffering pod failure where the gauges do there own thing and the centre screen packs up.
 
#29 ·
Hi guys
Excuse me for reviving the old thread)
I'm having a problem with my fuel gauge it stops just under the half full mark and doesn't move at all and the fuel low warning doesn't come one as I found out yesterday when I run out of fuel on a406 in London.
What can the problem be please?
As I understood if I'm not mistaken it's one of the sensors for fuel level.
Thanks in advance for your help
 
#30 ·
Check your range indication corresponds to the fuel in the tank when full and it goes down. That way you can see if the needle departs from reality or if both range and needle agree then you know it's the sensor.
 
#33 ·
Have a read of the Mk1 knowledgebase for access. There are two sensors - one for each half of the split tank. They are wired in series so add together so that the mean level is detected regardless of how much fuel share is in each tank half.

In your case it could be that one float is stuck or the wiper is not making contact - so that one reads full all the time stopping the needle dropping below half way whilst the other float effectively gives its reading in the top half of the gauge. Either float could do this.

You also have the complication that some cars were fitted with sensors that go high to low resistance as the fuel level drops and some cars have the resistance go the other way. The way to tell for sure is to pull the connector off and see if the gauge goes to full or empty.

You can try cleaning up the tracks with IPA or switch cleaner. At the same time you can check that the floats move freely. You can also measure the resistance of each sensor to determine which is at fault.
 
#34 ·
I know this is an old, old thread but ....

... tried this yesterday and so far so good. Thanks to the original poster.

A few things I would say -
- there must be a knack to wiggling the dash out, I made a proper mess of it and scratched up the top face plastic of the steering column. I'd recommend covering with masking tape before you start
- the needle is a pain to remove. I used a lightly modified dessert fork to lever it off
- make sure you wipe finger marks of the reverse side of the dash glass
 
#35 ·
Two teaspoons either side and pry the needle up.

Here's a lesson in pod dismantling

But just FYI if you are doing this to change a motor you don't need to remove all needles and face as I did in the video just the needle in question and work from behind

 
#37 ·
I read this.
I tried this.
I drove for a few weeks with the front removed from the clocks.
In those few weeks, all worked fine, temp and fuel.
Front back on and the temp gauge is back to its tricks because of the rest stop but the fuel gauge is fine but I dare not put more than ÂŁ40 in it as that's what set it off in the first place.

Not a bad solution if it's the memory but and not the actual motor which has died.
 
#39 ·
HattieBrooks said:
My fuel gauge has suddenly stopped working, and permanently reads half-full. I've been told that this could be a costly repair - does anyone know any different?
[smiley=gossip.gif]
Hi, If the fuel range shows about the same as the gauge but it is incorrect compared to how much is in the tank, then it's usually the fuel level senders in the tank, otherwise faulty dashpod.
Hoggy. :D
 
#40 ·
Hmmm, interesting. The fuel pump was replaced a couple of weeks prior to this prblem developing. When I complained to the garage that did the work, it said it would replace the fuel pump again, which it did, though still the gauge does not work. The garage is adamant that this problem is to do with the gauge and not anything to do with thr work it did. Any thoughts on this?
 
#41 ·
HattieBrooks said:
Hmmm, interesting. The fuel pump was replaced a couple of weeks prior to this prblem developing. When I complained to the garage that did the work, it said it would replace the fuel pump again, which it did, though still the gauge does not work. The garage is adamant that this problem is to do with the gauge and not anything to do with thr work it did. Any thoughts on this?
Hi, Is this a quattro or fwd TT?
Quattro has 2 pumps & 2 level senders, fwd has 1 pump & 1 level sender & are part of the pump, so it's possible garage has caused the problem when replacing the pump.
Hoggy. :D