Fuel Gauge only reports half full tank even though its full...

[hrstar24]

Hey guys I got an 2004 A4 3.0, and so far I love it, but just recently my fuel gauge has been having problems. I filled up my tank to full a couple days ago, and the next day I noticed that it already said half my tank was gone. I thought this was really odd, since I had only driven about 30 miles since the fill up. I was able to make it about 200 miles before the gauge read empty, so I went to a different gas station to fill up. This time the gas pump shut off after only filling up 8 gallons (15 gallon tank), like I already had half a tank. My inclination is that the fuel gauge is inaccurate, saying I am on empty when I actually have half a tank. Is this a common problem? Is there an easy fix, like a blown fuse or a wire that has come undone? I don't want to take it in to the shop just yet, because I just know they are gonna charge me $200 for a new assembly.

[hrstar24]

Update: I searched the forum and found this post about a malfunctioning fuel gauge

http://forums.audiworld.com/showthread.php?t=2757388

I tried it, I pulled out fuses 15 and 28, turned the car on, replaced fuses, and it did not fix the problem.

Anyone got any other suggestions?

[rohit13]

Originally Posted by hrstar24

Update: I searched the forum and found this post about a malfunctioning fuel gauge

http://forums.audiworld.com/showthread.php?t=2757388

I tried it, I pulled out fuses 15 and 28, turned the car on, replaced fuses, and it did not fix the problem.

Anyone got any other suggestions?

Fuel senders is where my money's at.

[tenspeed]

Originally Posted by hrstar24

My inclination is that the fuel gauge is inaccurate, saying I am on empty when I actually have half a tank.

Try some fuel system/injector cleaner. Some GM cars have had this problem due to some change in the gas.

[a44me2]

I agree, add fuel system cleaner to your tank for the next few fill ups. I had the same problem ,and it worked for me.

[sonofsousi]

hey im having the same exact problem for about 6 months now. i dont think it has to do with the fuses (i tried that to), nor do i think it has to do with any fuel injector cleaner... but at the same time i have no idea what it is.

[ezveedub]

You most likely have a bent fuel pump assembly rod. If so, you will possibly need a charcoal canister and fuel pump assembly. The tank ends up not venting due to a clogged charcoal canister, and the tank build vacuum and sucks the tank inwards. This will push the fuel pump assembly upwards bending the mounting rod and making the fuel sender tilt up at an angle, throwing off your fuel gauge readings. You need to take the fuel pump out and sit it on the floor. The top of the assembly is attached to the bottom housing with a rod. That rod needs to be straight. If its not, then you need to replace the pump.

[Vincent Borelli]

Hey, I actually had this issue when I bought my 03 A4 1.8t Q last month. After a bunch of reading online, and praying I didn't have to replace the instrument cluster, I stumbled upon this DIY to clean the fuel tank sending unit.

http://vader.inow.com/~drbob/fuel.html

I used 2 foot prybar, and a deadblow hammer, to remove the retainer ring. There is no way in hell I was gonna spend the $100 to buy the fuel pump wrench. It took two of us, one to hold the bar and the other for the hammer. Took about 10 good whacks to loosen it up. The rest is really easy. I also can't stress enough to use gloves and a mask, and do this in a well ventilated area.

Good luck