Pelican Parts Forums

Pelican Parts Forums (
-   Porsche 911 Technical Forum (
-   -   Full tank of Gas and... (

Blue83Cab 06-09-2011 03:31 PM

Full tank of Gas and...
The other day I topped off the gas tank and after driving for a few minutes the cabin had a strong gas smell. It would come and go and it would become stronger when I would be driving curvy roads. after a few days of driving the smell went away when I hit about 3/4 of a tank. I am now at about 1/2 and no more smell.

Any ideas? Is this normal?

Thank you in advance for the help.

crustychief 06-09-2011 03:44 PM

It is probably a cracked vent line in the trunk area, If it is then you might want to consider replacing all your vent lines and fuel lines soon to avoid a fire.

70S Targa Guy 06-09-2011 03:51 PM

I had the exact same problem and symptoms and fixed it by replacing the round cork gasket on the gas tank sending unit. Part # 914-201-891-00-M82

I would check out what crusty said also.

356graham 06-09-2011 06:10 PM

Or it could be the gas cap seal has finally gone bad. Happened to me.

Replaced it and all was well. Hope it's that easy for you.

twistoffat 06-09-2011 11:01 PM

This is an old quote in relation to this problem from the master himself Grady Clay

When you open the trunk or passenger compartment, do you smell fuel?
Is the car in a ‘sealed’ garage? If so, does it smell of fuel?

Has anything ever been done in/around the tunnel (fire extinguisher install, etc.)?
Does your A/C also draw air in at the rear of the tunnel (is there a grill or solid panel at the rear)?

The easiest diagnosis it to simply take the trunk carpet out and inspect.
It might be best with the fuel tank full to the brim (you can always pump the fuel out).
The places to look are at the breather/evaporative emissions system, the fill hose connections and the fuel level sender gasket.

While I can’t imagine finding fuel, it might be worth a look behind the passenger floorboard.

More likely is the area above the front ‘pan’.
Here is your fuel pump, the hoses and connections to the tank and to the pipes in the tunnel.
There are only three hoses with six connections and the pump.
Any leak should be obvious.
All it takes is slight discoloration where a hose meets the fitting.

About the only other possibility in front is the tank itself – VERY unlikely.

Fuel leaks at the engine are usually not noticed in the cockpit unless through the heaters (when on), not A/C.
When you are under the car, look at the two connections at the rear of the tunnel.

Needless to say, inspect everything in the engine compartment.
Fuel leaks there are critical.


Blue83Cab 09-12-2011 06:22 AM


I am trying to figure out two things:
1) Is the red circle show the ventilation tubes for the gas tank? I want to start to check this to make sure that it is taken care of. I think that I am going to try and fill it up this weekend and check for any leaks. I am thinking of just replacing all of the vent hoses, etc.

2) Is this where the washer fluid box is located? I believe that I am am missing mine and just want to make sure before I go out and buy one.

Thank you very much in advance for the assistance.

twistoffat 09-12-2011 07:57 AM

The Vent tube is the left of the Filler Neck at the bottom of the red Circle.
The Washer resevoir is located under the arch at the front of the left front tire

KNS 09-12-2011 08:02 AM

The washer fluid tank is behind the left headlight.

Those circled in red are the vent hoses. One of the lines has a small restrictor in it. It goes from the plastic canister, under the large supply line and up, and connects to a hard opening in the fender behind your fuses. If you carefully squeeze the hose you'll feel it, it is usually about 1/3 to 1/2 the way up along the hose. It is a pain in the neck to replace with the fuel tank in place.

If you replace the hose, cut open your old line, fish out the restrictor and insert it into the new rubber line. This must be in place.

andyt11 09-12-2011 10:00 AM

My first thought is the sender unit gasket. If you don't often fill the car it will dry out and leak when you finally do.

5String43 09-12-2011 11:41 AM

+1 on the gasket for the sending unit. That was the problem with a '69 I had. The replacement at the time was rubber, not cork, so that should solve the problem for a good long time.

Blue83Cab 09-12-2011 03:58 PM

is the sender the sender unit gasket hard to replace? or just a basic loosen, install, align and tighten?

jsveb 09-12-2011 04:53 PM


Originally Posted by 70S Targa Guy (Post 6071250)
I had the exact same problem and symptoms and fixed it by replacing the round cork gasket on the gas tank sending unit. Part # 914-201-891-00-M82

I would check out what crusty said also.


My friends 88cab does the same thing it is the level sender gasket.

70S Targa Guy 09-17-2011 08:36 AM


Originally Posted by Blue83Cab (Post 6250783)
is the sender the sender unit gasket hard to replace? or just a basic loosen, install, align and tighten?

Very simple job to replace Sending Unit Gasket. I am sure you know where it is located but just in case it is denoted by black arrow in picture below. Here's how I did it:

1) Disconnect battery-(I always disconnect battery when working on electrical components associated with fuel system)

2) Remove connector plug on sending unit by simply pulling upward. Remember orientation of plug for reinstallation.

3) Remove the screws that secure sending unit to gas tank.

4) Pull out sending unit carefully out of gas tank and be gentle with it as the components are quite sensitive.

5) Remove old gasket, clean area for new gasket, install new gasket and install sending unit back into tank. Tighten screws gradually in a criss cross pattern to ensure even sealing of new gasket. Make sure all screws are very tight.

6) Reinstall connector plug and connect battery.

Enjoy driving your 911 without any gas fumes!

All times are GMT -8. The time now is 07:51 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.