4000 Q fuel problem - tank

[Matt Suffern]

Tony,

I struggled with this problem for a long time.  It seems like the only feasable solution is to replace the tank and hope that the next one is rust-free...  Until of 
course it rusts up again, and so on and so forth.  The major problem, as far as I can tell, is that Audi decided not only to use a really crappy coating on the inside 
of the tank, they also placed a "screen" of sorts on the end of the supply line inside the tank.  This screen is easily clogged by the rust problem, and prevents any 
sort of aftermarket tank sealer from working since the fine mesh is blocked instantly by a coating of tacky sealer.  A removable supply line would have easily 
prevented this, but no...

As you can see I'm a little bitter about the whole ordeal, all the more since my own fuel pump has been intermittenly noisy lately, only about six months after I 
replaced the tank with another.

Pics of my old tank, after I took an angle grinder to it, are here:

http://www.unc.edu/~msuffern/audi/ft1.jpg
http://www.unc.edu/~msuffern/audi/ft2.jpg

That's POR-15 fuel tank sealant, great stuff, but it completely clogged the screen.

*sigh*

Good luck!

Matt
'86 4kq
Chapel Hill, NC


> Message: 7
> Date: Thu, 9 Dec 2004 17:01:04 -0800 (PST)
> From: Tony Hoffman <tfh400036 at yahoo.com>
> Subject: 4000 Q fuel problem - tank
> To: Quattro at audifans.com
> Message-ID: <20041210010105.86539.qmail at web53910.mail.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
> 
> Well, I got into the noisy fuel pump problem today, and when I 
> pulled the feed line off, it barely trickled out. Pulled it 
> upstream of the pre-filter, ditto. Pulled the return line, and holy 
> sh**, poured all 15 galons or so out. I filled the tank originally, 
> thinking the problem was it was empty. Turns out the fuel gauge 
> doesn't work. So, now I have 15 gallons of fuel in 5 gallon 
> buckets, and one hell of a rusty tank. When I put the compressed 
> air into the return, it blows right in. Do the same with the feed, 
> and it blows back at me. It appears that Audi put a second "shelf" 
> into there, so the gas wouldn't run away from the hole when 
> cornering. Good idea, Foxes would cut out below 1/3 under hard 
> cornering.
> 
> The problem that it brings up is this, I can't get to the feed to 
> clean it of the rust or whatever else is in there.
> Anyone out there delt with this before?
> 
> Anyone near me with a spare good tank for a 4000Q? I'm in Oklahoma City.
> 
> Tony
>