Gas Math
March 31st, 2006 - 4:20 am
I spent some time tonight doing math. I hate math. What sort of math was I doing? Trying to figure out where on the gas tank the leak may be by how much gasoline I could account for from the last full tank.
There were four gallons in the tank when I filled it today. Judging by odometer readings and my usual average gas mileage, I can account for another 4-5 gallons. That means that in the last 56-60 days, approximately 8 gallons of gasoline are unaccounted for … a half a tank … just over a cup of gas a day. After checking the amount in the plastic bin I am letting it drip into about an hour ago, I think that’s a pretty accurate estimate. That leads me to believe that the area that seems most wet, which also happens to be just above the seam across the middle of the tank, is likely where the leak is to be found.
With this knowledge in hand, tomorrow I will set about siphoning off 8 gallons of gasoline (I knew all those damn small gas cans I keep having to buy when I don’t have one would pay off one day), and then watching to see if it still drips. Bet you it doesn’t. That gassy smell I said it always has? It isn’t always at the same strength. This leads me to believe the leak is intermittent … like only when the gas level is above the leak.
I’ve moved from the brooding stage to the “let’s figure out how to fix this” stage. So you see … I am still not ready to give up on that car. You knew that though, didn’t you?
I am ready to consider getting a motorcycle (been thinking about it a while). Won’t that make my mom happy? 
I’m going to go find something to watch on TV or do some work on some artist trading cards. I should go to sleep, but it’s almost morning already. Might as well just stay up. Not sleepy anyway.
8 Responses to “Gas Math”
I have a 1971 Dodge Demon and the gas tank in it leaks as well. I think it was the original tank. Anyhow, I’m not sure if the older Dodges had a problem or not, but when you said that you think it only leaks when the gas is at a certain level, I knew I had to respond. See, that’s the case with mine. I can never fill the tank completely because once it gets to a certain point, it leaks. And mine leaks faster than yours seems to. I’m thinking my leak is where the tube that leads to the tank (which I can see in my trunk) is joined at the tank itself. That’s my guess anyhow.
My solution so far is that I never fill the tank more than halfway, otherwise it leaks. As long as it is halfway or less, I don’t have a problem with it.
Another solution is to simply put a new gas tank in. We were planning to do that at some point anyhow. It’s only a few hundred dollars, which is cheaper than a new car. They also have fuel cells, which are more commonly used in cars that will be raced, but they are also about the same price and I believe they weigh less. That was a common car, so I know you can get parts. Try http://www.yearone.com or there’s another place called The Paddock, but I’m not sure of the web site. You can pretty much get replacement stuff that looks like the original stuff there. Plus there’s plenty of Mopar groups online that can direct you as well. Mopar owners are a pretty tight knit group of people and tend to help each other out.
Anyhow, good luck with it, and I hope you don’t have to get rid of the car since it is sentimental to you. I’m at the point where I may have to sell mine and I really don’t want to. But at least it wasn’t my Dad’s car or something like that. We want to fix it up, but we never have the money or the time to do anything with it and now it needs brakes, so it’s not even being driven. We have 4 vehicles and a motorcycle and right now only one of the vehicles and the motorcycle are running. And the truck is not running right, so it will have to go in for service soon. We need a new motor in the Honda, brakes on the Demon, and I don’t know what on the 81 Cougar. That car was hubby’s grandfather’s, so I think that’s why we still have it. If we could get it running, it’d be nice because the inside of it is spotless. I know it has sentimental value for hubby, but we’re at the point where we need 2 RELIABLE cars, not 3 that don’t run and 1 that does. So I may have to part ways with the Demon. We’ve already had strangers come knocking on our door with cash in hand wanting to buy it, but we told them it wasn’t for sale. That guy drives by every so often because he said if he ever sees a For Sale sign on the car, he wants to be the first to get it. He had one in high school and has been wanting one for a while, I guess. That probably means he’s willing to pay a decent price for it. I don’t know. I just hate the thought of selling it. I love driving the car because it rumbles with that 360 in it.
Oh well, I’m babbling as usual but you already know I tend to do that…
I fixed the gas tank in my Jensen with JB Weld. It was actually the recommendation of a friend of mine whose father is a welder. I sanded the tank to find the holes, sanded those down to bare metal and then applied a generous coating of JB Weld. After everything dried, I painted the tank so it wouldn’t rust more and went on my way. It never leaked again.
If you don’t want to replace the tank, you can try that. If it doesn’t work, you’re only out a couple of dollars.
JB weld works fine, but have to thought about calling around to a auto salvage yards, asking if they have a wrecked Dodge of your vintage. They will pressure test it while you are there to see if it leaks. If you use your womanly charms they may even install it for you at a minual cost.
Ha, I ended up at Yearone right before bed this morning and found the new tanks. Lin said that was a great price, soooo … for the time being, just not going to fill the tank anymore (not a problem really since I only drive 6 miles a week) and get a new tank put in when we can. I’m keeping it, at least a while longer. It’s just been one thing after another with that car, but fixing it up somewhat will be the cheapest option for my transportation right now, and well, it’ll make me happy.
It’s interesting that your Demon has the same problem, and after checking out what’s going on under the car today, it looks like the leak may very well be where the fill tube connects as well. The whole back bottom of the tank is wet today, which seems to me to mean it’s running down from somewhere. After I saw how the tank was built and put in (and reading some MOPAR message boards), the fill tube seems to be a problem on these cars. It’s a weak point apparently.
We have too many non-working cars as well. There’s the Corsica, which I would personally like to blow up. Who knows what all it needs, but a good guess would be an entirely new engine. It’s just busted and was a lemon the whole time we have owned it. Then there’s Lin’s Jeep Grand Wagoneer. It was the first new car he bought, and he loves it. It needs new freeze plugs, some engine work, new tires, and probably some brake work (can’t even remember anymore). When we moved it from storage to the house, it actually started and we drive it up onto the trailer. I was shocked, seeing as it had been sitting in storage for about a decade or more. Then there’s the always somewhat busted Dart. And for some insane reason, Lin’s old work truck is still sitting in the yard as well, and then there’s the old sailboat and a tiny broken scooter. If you need old and busted transportation, we’ve got it. LOL!
There are people who would love to buy my Dart. Everyone who stops and comments on it (all the damn time) says if I put a for sale sign on it and drove it through my neighborhood, I’d be swimming in offers. I’m sure I would. People ask me if I want to sell it all the time. Probably if we had another working car, I would have sold it to someone who really wanted it a long time ago, but it’s been the only reliable car I’ve had in ages. It may have a hundred other things wrong with it, but it always starts and runs. It’s never broken down and left me stranded. Running out of gas? Yup, happens about once a year … usually my own damn fault. I can tell when it’s getting low on gas, which is why I went to get some yesterday, even though my math was telling me I should have a half tank left. It rumbles differently when it gets down to about four gallons and stalls a little on sharp, fast corners.
The greatest thing is that Lin wants to keep it and fix it up too. I expected some resistance from him on that, but I guess maybe he figures it would be better to invest in my nasty old car than have to live with a grouchy, pouting, crying woman for a while after we got rid of it.
JB Weld is one of God’s greatest gifts to mankind. We are probably going to look at the state of the old one first, but now that I know new ones are easily available and not so pricey, might as well just get a new one and be done with it.
I am going to scope out some junk yards for other bits and pieces that don’t necessarily have to be brand new but need to be replaced (like the damn dash). Besides, I love old auto yards. You can find the coolest things lurking in them.
Well, you were a step ahead of me then on getting over to Yearone and reading the Mopar message boards. If I can get the brakes fixed on the Demon, it will be okay to drive. I just never fill it more than halfway, which means I usually have to keep the key turned on so I can see where the gas gauge is at while I’m filling it. The few times I have overfilled it and had it leak, it wasn’t a problem except for the gas smell and the fact that I would be dripping gas as I left the station. That part always worried me because someone could throw a cigarette out and cause an explosion. But as soon as it went just below half a tank, there was no leak anymore. I’ve been driving it for over a year and just not filling it up all the way. It leaks oil too, but I just keep a check on that. Oh, and my power steering leaks really bad and now I’ve lost the cap to it. I always keep a bottle of oil, a bottle of power steering fluid, and water in the trunk, along with Fix A Flat (I have no spare tire) and some jumper cables.
I would go with the new tank as well. My gas tank has a bit of junk in the very bottom so if I run it too close to empty, I sometimes have problems with stuff getting in my carb. I installed an inline fuel filter and fuel pressure regulator to help some with that. It’s a good chance you might have some residue or junk in your gas tank as well, so I would go with the new one. I worry about anyone sanding or grinding on my gas tank because I really would hate to get any little metal shavings in there.
I always keep a bottle of oil, a bottle of power steering fluid, and water in the trunk, along with Fix A Flat (I have no spare tire) and some jumper cables.
Hee hee, me too! I also keep spare brake fluid on hand. Everyone I know who owns an old Dodge has all these things, and interestingly most of the same problems. Don’t get me started on the power steering cap thing. I don’t even remember the car ever having the proper cap. I’m sure it came with one, but somewhere along the line it got lost and dad made a new one out of something that looks like an old metal milk bottle cap. Hey, it works. Mine doesn’t drip much oil, but it does a little mostly during the summer when it gets so darn hot. It looses a little brake fluid now and again. I think the gasket on the brake cylinder needs to be replaced. It’s not leaking, but it just vanishes very slowly over time. A new gas tank seems the way to go. As soon as I realized they weren’t that costly and actually aren’t that hard to pull out and change (I figured it would be a pain, apparently it’s pretty easy), I felt a lot better.
Actually, I think I just had a major panic attack about it, because I realized that I have been driving a leaking car for quite a while, and well … could have blown up. That will give you a moment’s thought about impending doom.
If the silly car would just really break down, I mean something huge, I’m sure my attachment to it would disappear instantly. I used to love the Corsica too, but when it finally started acting like a total piece of crap, I had no problem hating it. When the engine finally went, I wasn’t heartbroken at all (almost thankful, in fact). For all the Dart’s problems, it’s a good car. Everything that is wrong with it is just little stuff that wouldn’t be all that hard to fix … might take time and a little money is all. We’re just going to have to do it if we are keeping it, and dammit, we are keeping it.
Now I’m just going to have to get naggy with Lin about getting some of this stuff done. For the time being, I guess I’ll just be careful about not putting more than a few gallons in at a time (and we are going to adjust the brakes this weekend - how they keep unadjusting, I don’t know). By Monday, I’ll be back to driving my 6 measly miles a week and life will return to normal.