How do I drain my fuel tank?

J11HNK · 11-10-2006, 09:49 AM

Hi, I recently noticed my 2000 996 C2 cab had developed a missfire, thinking back to its last fuel stop, I remembered finding it very difficult to fill without the pump cutting out. The following week I noticed the petrol station was closed to have new tanks installed. I spoke to a colleague who lives in near the petrol staion who told me that there were rumours that the previous tanks had been contaminated with water.

I have tried fuel additives to absorb the water but no joy. Theres an anti syphon valve so I can't suck the fuel up the filler neck & I've tried accessing the fuel pipe underneath, where it enters the filter, but there seems to be a some kind of restriction preventing me from syphoning.

Any ideas gratefully received

AFJuvat · 11-10-2006, 06:19 PM

Methanol will absorb the water.

The only way I can think of it drain the tank is to do one of the following:

Remove the battery, battery tray, and then the fuel tank sender and siphon the fuel out that way.

Or

Jump the fuel pump relay after disconnecting the fuel filter. This is difficult as the fuel filter is under the car, in the center tunnel.

I would suggest trying the methanol first.

AFJ

J11HNK · 11-13-2006, 11:13 AM

Thanks, I managed to siphon the fuel out following your instructions, then ran the engine until it was completely dry. After filling up with high octane fuel, I drove the car a little over the weekend & it seemed fine. Unfortunately whilst on the way to work this morning it stuttered again. Not as much as it had done previously but it seemed especially bad when holding the throttle in 2nd gear at about 3-400 RPM. It is fine under hard acceleration and when ticking over. Could there be a trace of water in the filter or somewhere else in the system or have I been barking up the wrong tree?!!!

AFJuvat · 11-14-2006, 01:14 PM

I would try swapping the fuel filter. Water can get trapped there.

AFJ

hotwire73 · 03-26-2015, 05:45 PM

IM having some issues with this draining the gas tank project. One I had to change the filter out since I couldnt get the water out of the gas. I have the filter off, and jumped according to what Ive seen, but its not pumping anything out. I have the filter completely removed, and taped off the supply line. I also noticed the pic showing the jumper for doing draining under the battery compartment is wrong, just read the two it says to jump, and look at the pic, they jumped the opposite. I did it to match them but nothing happened. Even done it the opposite way and nothing still. Any ideas, also does the key just need to be in 1st click, or 2nd click to actually turn the motor over to drive the fuel, I cant get anything either way. Is there a fail safe if the filter isnt grounded?