1973 carrera rs plastic gas tank

[denson]

Each time I open the front trunk I get a wiff of what seems to be a gas. I brought the car to my mechanic and he removed the bottom pan and no gas residue whatsoever. He also took the gas sender out, put a new gasket on and re-sealed everything, as well as putting in a new vent hose which was kinked. After all this, I still have the gas odor.

Is this normal to a plastic gas tank as I have never had one in a Porsche before? Any ideas are very appreciated.

Thank you,

John

[Steve@Rennsport]

Hi John,

It sounds like you might have a small crack in the tank.

My old lightweight RS had a small crack under the hold-down clamp that leaked when the tank was fiilled. I would remove the hold-down clamps and carefully inspect everything.

I fixed mine with some JB Weld that matched the plastic tank very nicely.

[mike curnow]

What bottom pan?

[nickd]

I'd guess John is talking about the sheet metal that cover the front suspension cross member , steering column / gas tank ports...... Protective plate 911 341 025 01

[Alan.uk]

The ones used on the plastic tank are also unique to that tank.

Alan

[gled49]

Usually those cars don't have charcol canister. If yours doesn't it will stink of raw gas. Gled

[BOYER73S]

Yes I'd back the cannister too

Its up under the dash on the RHS as you look from the front of the car usually held in place by a rubber band
and its where the fuel tank vapour is meant to vent to

[Alan.uk]

In case a pic helps, here is a plastic tank under tray.



Alan

[denson]

Thanks everyone for the help. The car does not have the charcoal cannister which is a good thing as one never came with the car. I appreciate the post from Alan including the picture of the correct bottom pan for the suspension and gas tank. I know need to find that pan as mine is different (thanks Alan, now I need to spend more money!) . I think at this point I need to have small cracks looked into and especially where connections are made. I hope this does not turn into a job where the tank has to be pulled to find the problem.

I will keep everyone posted once I find the problem.

John

[BOYER73S]

You will have great difficulty in finding that RS style suspension cover

What it actually is is an 73 style cover where an extra piece was welded in place at the factory to cover fuel line points of the plastic fuel tank

When I first saw the one on #197 I thought a previous owner had done the add on job but turns out it was factory.

Removing the fuel tank is very easy once its empty.

Finding a 73 style and modifying yourself is best bet I suspect.