No Fuel . . . Apparently

[Stuart Dobson]

Hey guys,
got a slight issue with my A3 at the moment. I didn't think the fuel guage was working properly a few weeks ago but now its gone wrong all together. I had about 25 miles left in it yesterday so I stuck a tenner in, and it went to about 30 miles. Got it down to 20 again and stuck in another £10 and it didn't go anywhere, I've put £20 in on the last 20 miles and the needle and mile thing hasn't gone up at all, its just slowly creeping down. I've now got 0 miles apparently.

Unless its doing 5mpg I think there is a problem with it.

Anyone had this before?

Thanks

 

[actualeddie]

Could be the fuel sender, its under the rear seat drivers side.

 

[MrTackalakalaka]

Yeah most likely to be your fuel sender.

I had a similar problem where:

If i filled up with fuel......it showed empty
If it was half way it was correct (i think)
If it was empty it would still show halfway.

Turned out the bit of wire had snapped causing the float/level that gives you your reading was dangling in my tank.

Unfortunately my local garage seemed to think i asked them to do the fuel tank unit.......even though i said i KNOW its my fuel sender thats faulty.

So took it to Audi and £500 later it was done. An expensive fuel gauge! haha
Just don't take it to Audi for it to be done

 

[Stuart Dobson]

Ahh ok, how do I get to it? Its it fairly straight forward to get to?

 

[MrTackalakalaka]

Offside rear passenger seat........take the bottom part of the seat out. Then lift up the black felt/carpet. You will then see a black cap.
Undo this and you can get to the fuel sender from there.

Be warned though.......you may get some fuel in your car so make sure you have plenty of rag or a sheet lying around and your windows and doors open

 

[MrTackalakalaka]

I think you need a special tool to get to it properly. Im not 100% sure but no doubt someone will be able to help soon

 

[Stuart Dobson]

Ok great thanks ill take a look at it later on, If anyone else has any further tips I would be grateful

 

[tubby-ben]

i done mine a few weeks ago, my float wasnt making contact on the arm properly so sender was thinking it was empty. basically lift your rear seats at the bottom and give them a good tug, you will see a round metal plate, remove this, i took my seats off my car as made it easier to work on. then undo the 2 pipes on the top, remember what one goes on each nipple (no not your own nipples), you will get fuel spill from pipes but not alot, flat blade screwdriver and hammer and spin the cap round, do not drop the huge rubber washer in the petrol as i did coz it will expand and is pain to fit back, then lift the float out in 1 go but carefull. if you can if you have a full tank drain loads of it out as you wont be able to get the sender back in without spilling gallons all over your car. the reverse it all to fit. try wiggling it all first maybe like mine and a dodgy connection...

 

[boost-addict]

now if my gauge shows 3/4 then 1/2 after 30 miles then back to half way between now back to half after 85 odd miles, would you say im best getting one before it dies,

what list price for a sender any way?

 

[tubby-ben]

they range from about 70 quid for a diy job or a proper unit is 200 quid. check that the arm on the float (the metal arm) is making contact , bend it inwards slightly. you will see like a silver circuit board type of thing by the arm that it brushes against. if it misses it then thats why your fuel gauge is no good. try sorting out first and save the money you would have spent out and get some goodies....

 

[Stuart Dobson]

do I need to take off the electric plug too? or leave that on?

 

[boost-addict]

nice one ben :thumbsup:

ill give that a go at the week end.

 

[Stuart Dobson]

Is there anything else it could be?

I did exactly what you said, took the whole sender out, gave a real good look over all the wires (luckily there arent many) to make sure they where all still properly connected. Then had a good look at the whole float system, making sure the metal parts where in contact throughout the whole movement (I gave it a very light press just to make sure but it seemed fine anyway). The only thing I thought I did notice is that the float may have been catching on the hose in the tank, so I moved that out the way.

Put it all back together, started the car and I'm still reading 0 miles, I left it on for a few mins to be sure but still nothing. I now also know that I have at LEAST half a tank, possibly even more because the reservoir on the sender was practically full.

Anything else it could be or is it a new sender job?

Thanks

:/

 

[Stuart Dobson]

Quite update, I pulled it off again, I felt a bit amateur not completely taking it to bits and giving it a full multimeter resistance test.

Tested all wired from top to bottom and the resistance circuit board and watched the resistance vary as I moved the float up and down. Then put it all back together and tested the connection from the top (in theory it would then make a full cuicuit and I should get a resistance from the float), it did exactly as I had expected it to, worked fine, hooked it all back up, turned the car on . . . Still nothing :/ Went for a drive around the block because I thought it might take a bit to settle . . Still nothing :/

Any other ideas?

 

[tubby-ben]

have you tried connecting the sender up without putting it back in the tank and move the arm whilst ignition on and watch your fuel gauge? just a thought, where are you based stu?

 

[Stuart Dobson]

No I didn't think of that because I didn't think I could get the pipes back on because there is VERY little movement with them.

I'm live in Suffolk, near Bury St Edmunds

 

[Stuart Dobson]

any ideas?

 

[s3dave]

You dont need the pipes on to check the gauge as it is electrical, but i would not advise to have any power in such a confined environment while staring at a few liters of V power...

 

[tubby-ben]

he should be ok the housing is earthed properly and its sitting in fuel anyway. ive seen it checked like that before but like you say it is petrol, petrol and sparks etc dont mix. id risk it but thats me being me. if it did ignite then yeah you would be pretty toasty in the back.....