Need advice with gas tank / leak.

[drdave]

I have a very strong gas odor emanating from in front of the rear wheel on the drivers side. Looking at the tank, about a 15% area of the undercoating on the bottom and slightly on the side has a shiny appearance to it, yet is dry to the touch. If you pinch off a small piece of the undercoating, it has a faint gas odor to it.

There has never been any evidence of a liquid gas leak, in other words, has never dripped on the ground, nor have I been able to feel anything wet.

What I'm wondering is if there is any history of problems with the tanks, maybe a good starting point for me.

I'm very mechanically inclined, but am more than a little nervous about playing with the tank too much, ya know, sparks and all! On the other hand, I'm not real crazy about all of those fumes hanging around my exhaust either; keep thinking about the space shuttle.

Any and all help would be greatly appreciated. My wife and kids thank you in advance.

 

[projectSHO89]

Is the timing of the occurance of the odors dependent on the amount of fuel in the tank? If so, sounds like the tank is leaking. Maybe, if you're lucky, it's just the seal on to where the pump is installed.

Otherwise, check for the extra long charcoal canister vent hose that was installed in some Taurii due to a TSB. Not sure where the termination of that hose is at except that it is near the rear wheel, perhaps someone else can geive the exact location.

If the source of the gas odor was on the other (passenger) side, it could be explained as a fuel line or filter leak.

Good luck.

<small>[ October 03, 2002, 08:14 AM: Message edited by: projectSHO89 ]</small>

 

[rangerj]

drdave,

The smell of gas fumes and the discolored coating on the tank are SCREAMING evidence of a leak.

If you are not comfortable working in the environment of flamable liquids, and/or fumes (Vapors), then by all means have someone else do it. The sooner you find out what the problem is, and have it fixed, the sooner your mind will be at ease.

It could easily be a hose that has dried out and cracked, the "O" ring that seals the tank where the fuel pump and guage sending unit enter the tank, and/or a problem with the vent line that runs up to the charcol canister.

If your car has been a Texas car for its entire life it is unlikely to be a hole rusted in the tank. However, the underside of the car, including the gas tank, gets hit with stones and road junk on a regular basis. Any of this stuff could cause a puncture. It would be unusual, but STUFF HAPPENS.

If you want to look into it further, before you take it to someone, keep in mind that a full tank is safer to work around than one that is less than full (less vapors). Work in a well ventilated area, and it would be a good idea to have a fire extinguisher and a friend near by.

I am a firm believer that all home mechanics should have a fire extinguisher in the garage, no matter what they are working on. I also believe that any time you are working under the car you should have someone nearby in case some STUFF HAPPENS. I look at it like SCUBA diving, that is, it should not be done alone.

Your instincts are correct, gas fumes are something to be concerned about. If you approach this with knowledge and common sence you can do it safely. Either way, something needs to be done real soon. Or as they say in Texas, "rat now". rangerj

 

[drdave]

Does the fuel tank vent to the charcoal canister in the front fender, or does it have it's own canister? If it vents to the front, I believe the line for that runs along the passenger side.

I have noticed that if the fuel level is low, I can have up to a 20 second release of pressure if I relieve the gas filler cap. This may be normal, but now that I'm looking for things, it sticks out. With more fuel in the tank, the release is less than 10 seconds. Of course, it's still sort of summer here.

Since the undercoating seems to be softening, it seems to me that gas is between the undercoating and the tank, leaning towards a small puncture.

As far as rust, there is not even a hint on my cars.

 

[drdave]

ttt

 

[luigisho]

Doesn't it vent near the gas cap? I thought there was a slot near the filler neck to allow pressure to escape. I could be way off on this as I haven't messed with the tank in some time.

 

[drdave]

Would anybody else care to add their expert input before I drop my tank?

 

[SHOfun 93]

Yea Doc, while you are in there, you might as well upgrade the fuel pump, as well as cut a little door to get at it under the rear seat to allow you to do further repairs/mod changes to it in the future. Good luck!

 

[drdave]

If my tank has a bad gasket, would I still get the large pressure buildup in the tank that I get? It almost seems to me that I have too much pressure in there.