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View Full Version : A6 C6 3.0 Quattro Runs out of fuel at 1/4 tank



dean warren
02-10-2014, 10:54 AM
Hi All i need some help.
My 2006 56 plate 3.0 QUattro TDi Aant had the dreaded zero Fuel problem when i brought it two years ago, but went away until 3 weeks ago. i thought may as well bite the bullet and do the loom fix. i tried it with scotch locks and it made no difference. so 2nd attempt was solder the wires and shrink wrap.
this fixed the problem and i now have a working Gauge for the 1st time in 3 weeks.
i filled the car and got to 500 miles 1/4 tank left. it started to miss fire and glow plug warning flashing. i pulled over and the diesel line was full of white froth. so i guessed out of fuel.
luckily there was a fuel station on that road.
put £10 in as i didn't want to have too much in when i opened it up later.
i was 20 miles from home and it started to misfire again so i put another 5 litres in.
i opened the drivers side sender and the fuel was almost to the point of spilling out. but only thing i could see was the black pipe from the passengerside was to the front of the in tank pump, so i moved it behind as it would be deeper in the tank. (Does this just sit in the tank? or should it connect to soething?)
i opened the passengerside and it was empty, just a few mm on the bottom.
there are no Faults in the Instrements so i guess Gauges are fine espeially as there was so much fuel in the tank.
i also ran the car with the drivers side closed back up, the intank pump is working you can hear it sucking/buzzing away.

So Why would it run out with so much fuel in the tank?
what should i be looking for?
Any help please.

MarkTM
02-10-2014, 01:01 PM
Kidney shaped tank 80l just like all 3.0's am guessing, you'll probably need to buy the wiring repair kit that ensures that both sides are level, from memory it was £28.

Am unsure if there's another pump in the passenger side but am guessing not if it was empty and you didn't see anything?

Do a forum search as I did list the part no on one of the threads, sounds as if you're competant enough to fit yourself, must be a complete mare knowing you've half a tank but you're running out of fuel :aargh4:

Peter D
02-10-2014, 01:18 PM
There should be no floating pipe from the suction jet pump. One pipe connects to the cover with a union nut and the other is located in through the top of the pump. Odd that the car stops. It could he the the floating pipe ( return from the suction jet pump ) is frothing up the deisel in the baffle tank and you are sucking it into the main fuel supply. Regards Peter

dean warren
02-10-2014, 01:23 PM
Kidney shaped tank 80l just like all 3.0's am guessing, you'll probably need to buy the wiring repair kit that ensures that both sides are level, from memory it was £28.

Am unsure if there's another pump in the passenger side but am guessing not if it was empty and you didn't see anything?

Do a forum search as I did list the part no on one of the threads, sounds as if you're competant enough to fit yourself, must be a complete mare knowing you've half a tank but you're running out of fuel :aargh4:

Cheers But i have fixed the loom, there are no DTC's now.
the repair kit would make no odds as i have soldered the wires.

dean warren
02-10-2014, 01:27 PM
There should be no floating pipe from the suction jet pump. One pipe connects to the cover with a union nut and the other is located in through the top of the pump. Odd that the car stops. It could he the the floating pipe ( return from the suction jet pump ) is frothing up the deisel in the baffle tank and you are sucking it into the main fuel supply. Regards Peter
yeah i have 3 pipes coming to the top of the sender / top section, one is supply out one is return one is a clear pipe to other side.
i have a black pipe loose it doesnt have a clip or fast connector on it. where does this go?
on the suction pump there are 3 holes on top, two are for the locating pegs on the top unit and a 3rd bigger hole, does it push in there?
Thanks

dan2485
02-10-2014, 06:26 PM
wrong post so deleted.

dean warren
03-10-2014, 08:32 AM
Well after an eventful drive home last night i have put the black pipe that was loose through a round opening on top of the intank pump unit as this always seems to be full of fuel, i guess this sucks and fills from the lowest point. so far i have driven to work with no more fuel added and its 25 miles, i want to run it to zero miles and fill it so i can restore my confidence with the tank range.
Cheers

Kristopher S
28-06-2020, 09:41 AM
There should be no floating pipe from the suction jet pump. One pipe connects to the cover with a union nut and the other is located in through the top of the pump. Odd that the car stops. It could he the the floating pipe ( return from the suction jet pump ) is frothing up the deisel in the baffle tank and you are sucking it into the main fuel supply. Regards Peter

Hi Peter !!Do you have any drawing on how and where this pipe should be connected? I have the same problem

wezzo2021
04-10-2021, 12:47 PM
Me too - Anyone??