nrider42

Hi Folks, early 1985 Euro 944. I have been suffering with bad gas fumes in the cabin since I purchased the car a little over a year ago. The fumes are the worst if I fill the tank over 1/2 way and after I have been driving aggressively. I had checked the vent lines and hoses in the filler area from inside the car and saw nothing obvious (other than a replacement hose). I could see some dampness on the front side of the tank which looked to be coming from the top of the tank after I had been throwing it around a bit. Soooo....I read all the posts and it seemed like a classic cracked tank. I pulled the tank today and am a bit confused.

What I know:
- The tank is coated in a heavy undercoating product which does not look like anything I have seen on any other 944s
- The line which runs across the top of the tank has been replaced with rubber hose. It is not the fiber wound hose which seems to be original.
- I see no obvious cracks

What I don't know:
- What is that triangular plastic thing which is in line with the vent hose across the top? What purpose does it serve?
- Should I try and remove all of this undercoating? It is pretty thick (see swirly stuff in pictures).
- Where else are likely leaks?

What to do?
- My plan was to take this to a radiator shop and have them boil it and pressure test it. Seem reasonable?
- Should I try and get the original style vent hose for the top?
- Can I get rid of the plastic triangle thing?
- What am I missing....

I have attached some pics of the tank. Any help or comments are appreciated!

Thanks,

Nate

nrider42

Did some more research...google...duh....

The triangle thing is an expansion bladder, the fibre wound hose is available at Pelican.

Will try and remove the undercoating and perform said tests...tried to delete my original post but couldn't figure out how..

Cheers!

Spidey944

As long as the replacement fuel hose is NOT bulk coolant hose it should work just fine, just not as flexible as the OE braided stuff.

As far as the smell goes, I would say the fuel sending unit seal is most likely your cause. Sadly since the tank appears to be removed already, it will be hard to prove. This is where a smoke machine comes in handy to pressurize the tank with a few pounds of smoke. Where you see smoke, that's your leak!

Kerry Chadderton

Nate,

Look under the center of the triangular plastic "Dohicky". See the round indention in the tank there? This is a problem with the metal tanks. The press operation thins out the metal so much that they crack there. This may or may not be your problem, but it was on mine. Same symptoms as yours. Since you have it out replace everything but also scape away the undercoating and check that area. I haven't seen an early tank with that much coating either. Your tank may have been repaired before.

nrider42

Thanks Kerry! I will remove some of the undercoating and take a peek. How did you fix yours...did you use a big copper patch like I have seen elsewhere?

Thanks,

Nate

Tiger03447

I see that a guy on E-bay has the cloth braided fuel hose for about 14.00/ meter..might be able to re-use the old fittings after they are bead blasted and save some $$...hopefully they can be re-crimped with new ferrules...hydraulic shop? jus sayin..Thanks, Tiger 03447

Kerry Chadderton

Nate,

The cracks are small and seep rather than leak. Enough to cause the smell. I cleaned the areas with a stiff wire brush on a drill. I wanted a scored surface. I used JB Weld as a primary and then coated the top with a product called Seal All that HVAC companies use on A/C units. I also replaced every line in the area. Now, if that odd factory seal around the gas cap area is torn it will cause some fumes to enter the cabin. I have no more issues.