SteveAngry

Well, took the car down to my local mechanic and had it put on a lift today. My fuel tank has rotted out at the front seam and is pissing all over my driveway...

Not good. Mechanic said that the fuel tanks were $800-900 and labor would probably be another $600-800. He said he has never done one yet so that was all of the top of his head from when he used to work at a dealership. He said he'd get me a better estimate in a day or so...

If it is a $1500-1800 repair bill, then this car will end up being parted. I can't justify another repair bill like that on this car. If the car had perfect paint, etc, then maybe I would have considered it.

I'm bummed.

Anyone had a gastank redone lately? Got any prices?

I have one more place to check to see if they can remove the old tank and repair/recoat it. We'll see what they say...

Audi should have used plastic tanks...

Steve
Michigan

180q

I was under the car last night fixing an exhaust clamp, and found that one of the fuel lines under the car is pissing....uh oh. That can't be any easy/cheap fix either. It may be put to rest.

Good luck,
Chad

AudiSport4000

Sorry to hear that. Id hate to see such a neat car get parted out, I really like it. Of course, we just had the gas tank convo what, 3 weeks ago in Kzoo? I take it your not going to make it for Putnam tomorrow?

Mike

RussB

For that big a potential repair bill savings, I'd investigate replacing the tank with one from a junked car, or if that's impossible, try coating its innards. (What have you got to lose?)

In the late 1960's, I stopped a gas tank leak in a Jaguar's gas tank by simply coating the tank's innards with some goop that was intended for use in light aircraft. I did nothing special in terms of metal prep, and it stopped the leak til I sold the car maybe two years later.

More recently, I have a motorcycle with a rusting tank that doesn't yet leak, but looks like it may do so any day. New tanks for this bike cost about $800. I'm gonna try a three-part tank coating product called Kreem. It's had good reviews.

Here's a detailed description of tank preparation:<ul><li><a href="http://www.sonic.net/~blaineh/kreem.html">http://www.sonic.net/~blaineh/kreem.html</a</li></ul>

Tom Faust

At least locally junkyards are required to pull the tanks in cars before they go in the yard. What they usually do is just throw them in the trunk. What this means is that even in a pick-a-part, you just have to lift it out of the trunk. For reasons of clearance, the Quattro tank is different from the FWD tank.
The bad news is that the rear drive has to be dropped to get it out. I think the flat rate on this 4 hours. I forget if that is R&amp;R.
I would look at the leak to determine size. There are external sealers available. I have seen them in autozone. My girlfriend got her Dodge Dart through college by patching the tank with layered and increasingly larger patches of aluminum foil and super glue. That lasted 2 years. I might try just running a bead of one of the new bonding agents that they use to bond body panels. For instance most mini van roofs are glued on, as are most door skins. I am short of a trade name at the moment, but I know that 3M makes one. Before the eco-***** took charge, radiator shops could boil and seal tanks. Some still do, but it is frequently under the table and only if they know you. They don't want to be ratted to the EPA.
P.S. to assuage some fears, unruptured gas tanks do not explode in a ball of flame, as on TV

Tom Faust

If it is a flexible line, it shouldn't be that expensive. If it is a rigid line, see if you can't replace a section with compression fittings. I have them in my house plumbing where my water pressure is higher than Audi fuel pressure.

RussB

Go to section 2 Fuel System, and read pages:

*Fuel tank rust repairs - the epoxy method

*Fuel tank rust repairs - the POR-15 method

*Fuel tank sealer - like the air jocks do it.

*Fuel tank rust removal - a novel approach<ul><li><a href="http://www.morrowmarsh.ca/concours/techpages/techindex.htm">http://www.morrowmarsh.ca/concours/techpages/techindex.htm</a</li></ul>

RussB

Admittedly biased since it's by a manufacturer, but worth reading:<ul><li><a href="http://www.por-15.com/faqs/faqtanks.html">http://www.por-15.com/faqs/faqtanks.html</a</li></ul>

Tom Faust

First, I have used the POR and it seemed to work well. The downside in Steve's case is that the tank has to be removed. Whether with POR or any other sealer, the tank is cleaned with acid. The acid has to be sloshed around to reach all of the rust. It then has to be neuturalized,usually with water. This requires more rotation of the tank. When the sealer is poured in, the tank needs to be rotated on several axises for the sealer to reach all parts of the tank.
Off course, recoginizing that the leak is probably toward the bottom. If a drain could be found I suppose the acid wash and neuturalizing could only be done on the bottom where needed. Getting the sealer in the right spot requires more thought. Perhaps limiting the amount of sealer and parking on a steep hill? Maybe putting the back up on stands and letting the air out of the front tires? If a big accessible opening can be found in the tank, perhaps sealer can just be swabbed on the effected area? Seems to me there is a big opening. Maybe after a water wash you could stick a heat gun or vaccum cleaner through the opening to dry it? I have heard of POR 15 being injected into rocker panels with a homemade pipe nozzle (the guys on the Moapr board are ingenious and well equipped)try that. Sealing the whole tank is a worthy goal, but stopping the leak is the issue.
I have heard crazy stories about driving down railroad tracks with stone dustand crushed rock in the tank (I hang out on the Mopar board)This is supposed to remove the rust scale which may be blocking the filter on the fuel line. Assuming this works (reports are not reliable) it still doesn't solve the problem of distributing the sealer.
I would start with an external sealer. What's to be lost? There is a lot of magic in modern adhesives. Remember the girl friend mentioned in my other post with the super glue and aluminum foil on her tank (of course it was a Mopar).

shortyq

This is my experience as well. Your mechanic is smart *not* to quote book time tho, since on an old car, that's never going to happen. It's a one day job if you are lucky, I wouldn't touch one for less than 8hours. I too would search around and find some sealers first, the worst that happens is you are out 10USD more than what you face now.

HTH

Scott Justusson
QSHIPQ Performance Tuning