Disaster

[chiefmechanic]

Just got my 1993urs4 ready for retest when the fuel tank has started to weep fuel. Are they all metal tanks or was there any plastic fuel tanks made for this model. I have an s6 that I use for spare parts and was wondering if the tank in it is the same. I believe it's a pita to take the tank out as the suspension needs to be dropped away. Ideally I would like to patch this tank in the s4 in situe and change the other tank later in the year when I can get it out, check it over and do any necessary repairs. I have been told plastic metal will seal the tank and is resistant to petrol. Has anyone else used this or is there anything better for the job.

[WidowmakerS2]

The fuel tanks from Typ44, 4C, C4 (all quattro) are all a direct fit.

A few norwegians suggest using a bar of soap to seal it. The soap is supposed to react with the fuel and harden. Then you can seal it all of with some epoxy.
I guess you would be best of not pressurizing the fuel tank afterwards.

[Audicted]

Solution from North America:http://forums.quattroworld.com/s4s6/msgs/234798.phtml

[UrS4boy]

The C4 fuel tanks are metal. The PN, 4A0222201075L, shows no difference between sedans and avants. Note also there is no differentiation between quattro or FWD cars and that, according to my friend Kate, the same tank was used from the mid-1980's to 1997 including the S6plus (the end of the C4). Cars with the secondary (gasoline-powered Wesbasto) heater got a different (presumably larger) fuel tank (075B)

And yes, it is a royal PITA to remove and replace the fuel tank.

[spink]

Fwd are definitely no good for a quattro.they are plastic and a different shape
I disagree about it being a pita job,if you are going to attempt it on axle stands then yes you are asking for trouble and you will be pissed off. On a 2 post lift there is nothing remotely hard about it(I realise not many people have a lift but you can rent time on them by the hour or off friends of friends etc for not a lot).I have seen a couple of quotes from garages wanting to charge £700-800 labour wtf? Its a 3 to 4 hour job

100 and 200q do have the same tank but lack the fuelpump mountings inside

[Duffelcoat]

A non quattro tank is 80 litres and a quattro tank is 75 litres in the C4 at least so presumably they are different somehow...

[psiconauta911]

You can do as the pilots of fighters of the WWII and chew some gum and blank the hole with it as it hardens in contact with gasoline, that was the reason why all the pilots chew or had chewing gum with them!

[malncol]

You can do as the pilots of fighters of the WWII and chew some gum and blank the hole with it as it hardens in contact with gasoline, that was the reason why all the pilots chew or had chewing gum with them!

yep seen it done, ive sealed a tank with minties and it held for years
mal

[chiefmechanic]

Disaster

Phoned Audi out of interest. Back order from Germany only £847. Think I'll fix this one.

[twoqu]

A lot of radiator repair shops seem to offer a service called Re Nu for fuel tanks. Might be worth investigation at a later stage. Of course you would need the tank out of the car.
Typical Audi support for their older models and one that has undoubtedly caused the premature death of various decent vehicles for the sake of a bit of pressed metal. Not a lot you can do if you can't put fuel in your car.
I guess due to its odd shape and internal fuel pump mounting its difficult to get something made to replace it. Guess there might have been a market before the majority had been consigned to the scrapheap!

[Cottis]

Phoned Audi out of interest. Back order from Germany only £847. Think I'll fix this one.

For a fuel tank? Ouch. That is crazy. Get chewing fella!

[spink]

I used chemical metal fuel tank repair on my s6 back in 2010,lasted about 18 months.Managed to get a nearly new tank off another s6 last year and fitted that.

A place in my town does the recon thing,costs around £250 and they give a lifetime warranty on it

[daren]

If you can get the tank removed, use the lead loading technique, A good body shop will do it for a couple of quid.

[fundahl]

I just had to do this with a friend's Audi B5 A4. His was plastic though so we removed fuel using engine running and hose on fuel return line. Then we melted the fracture close with soldering gun. Then plastic epoxy on it. Holding well for a week now.

[chiefmechanic]

Fuel tank

No hole in the tank just an area 10mm in diameter where the fuel seeps through. Covered the area with plastic metal and it's still holding.