Small fuel leak coming from near the rear passenger wheel?

[bigredguy]

I have been driving my car for a good few weeks with the slightest smell of gasoline coming from under the car after I stop driving. Once it sits for a while and I return to my car, like after work, or after it sits for the night the smell is not there. I have just returned from vacation after a week and parked in my garage, which I normally do not do, and we got back and the garage reeked like gasoline and there was a 8 inch wide spot where it had been leaking, which I never saw any noticeable leaks before.

I am just wondering if this is a common spot for a leak and what the possible problem could be, and what kind of fix I am looking at. I know there should be some steel lines running under the rear passenger door, and also the gas tank is located there as well, but the leak seemed too far towards the outside of the car to be the gas tank. Could it be the filler neck?

I would like to get peoples opinions on what the leak could be and what kind of fix would be necessary. And also any possible ways to test for sure where the leak is coming from. Thanks

[RCM3]

Which side of the car are you suspecting this leak from? My 91 318i developed a leak like you describe overnight about a month ago. I started the car and looked under the rear driver side and immediately noticed drips coming from there (right in front of the attachment point for the rear sub frame). The repair was as simple as changing out one of the rubber lines that connected to the fuel filter that had developed a decent sized crack. Hopefully your issue is a simple fix also.

[Todd Black 88]

There is a rubber hose from the metal filler neck to the bottom of the tank. It's probably that. Mine failed and put an eight inch hole in my driveway.

[jlevie]

On the right side of the car a leak could be from the pump flange seal, one of the hoses that connect on that side of the car at the top, the fuel filler hose, or a rusted out tank. If the tank wasn't full while the car was parked, the pump seal won't be the cause. But the fuel supply/return lines would still be a possibility.

[bigredguy]

I just jacked the car up a bit and noticed that the bottom of the gas tank was a little wet. I believe it could be leaking from there, but I will also look into the lines and the filler neck as well when I actually get to a good floor jack.

If it definitely is the gas tank that is leaking how would anyone recommend repairing the place where it was leaking? I was thinking get most of the gas out, jack it up and actually find the hole and patch up a good area around the hole with a rtv sealant, and then spray the whole tank with spray on bedliner just to ensure its all sealed well. Any other suggestions on how to fix the leak?

[Todd Black 88]

Replace the tank

[bigredguy]

any other options to just seal the leak? I havent had a good chance to look at the size of the area leaking yet, but if its small Id imagine that the whole tank wouldnt need replacing. Also, there is no rust on the tank, I know this from previous times under the car and every time I do check for any rust starting to form, so the crack, hole wherever it actually is leaking from would be a clean area.

[Quadrajet]

Is the drainplug tight?

If it's not that. There is a gas tank repair kit, it's like a two part epoxy that you use. Surface to be repaired must be clean. Used this on a K5 fuel tank many years ago, lasted for a few years till I found a replacement tank.

[reelizmpro]

Check for cracks around the neck where the filler hose attaches to the tank. The hose itself may be loose, not on all the way or damaged too.

[george graves]

Before you do anything.....stop parking in your garage. Especially if it's attached to a house....with people in it.

[bigredguy]

Is the drainplug tight?

If it's not that. There is a gas tank repair kit, it's like a two part epoxy that you use. Surface to be repaired must be clean. Used this on a K5 fuel tank many years ago, lasted for a few years till I found a replacement tank.

I hadnt even thought to check the drain plug... I will when I get the car up on a jack though cause that could be something very simple. Through more research I did find others have used the epoxy. Is there anything special about it? Because I have quik steel epoxy which seems to be the same, just knead it until the color is uniform and stick it on.

Check for cracks around the neck where the filler hose attaches to the tank. The hose itself may be loose, not on all the way or damaged too.

Like I said earlier I didnt get a really good look at everything yet. When I am off work this weekend I will jack it up and check everything. From what I see though theres a small dent in the tank close to the side of the vehicle, which is where all the fuel seems to be leaking, which is why I believe it is the tank as opposed to anything else.

Before you do anything.....stop parking in your garage. Especially if it's attached to a house....with people in it.

The car was moved the minute I got home and smelled the gas. I dont ever park in the garage I park on the street usually, but I was going on vacation and my car is the only car in the family that fits in the tiny ass garage so I parked in there for the week. And prior to parking in the garage I had never really smelt the gasoline strong at all, so it didnt even cross my mind to not park in the garage.

[bigredguy]

oh and one pretty common answer I found when searching was using a bar of soap. I couldnt believe it, and will not use this, but Im just curious if any of you have tried this. It just seems too good to be true, but on a few old truck forums that came up when I google searched it people suggested it and then many people swore by it that it worked. They say it was an old remedy started back in the 60s, and apparently when the gasoline and something in the soap mix the soap becomes very hard and seals the crack.

I cant believe that this would work, and I dont think I would even attempt this, but Im just curious if anyone on here has done it.

[SmokeE30]

I would replace the tank you can get a new one for like 200 or a clean used one for less. If you absolutely can't replace the tank you could try Kreem tank sealer it works well in rusty motorcycle tanks but idk about a e30 tank with a hole in it. Plus the cost of the sealer and the time to take the tank out and do it you would probably be better off just putting a good tank in

[jd_e30]

Where to get a new fuel tank? I believe mine is leaking. Pelican lists it for around $700

btw, sorry for thread bump.

[SmokeE30]

Where to get a new fuel tank? I believe mine is leaking. Pelican lists it for around $700

btw, sorry for thread bump.

When I worked for Dorman we made a replacement tank for late models I think it was around 200ish you can buy it at rockauto or oriley or advanced auto ect