Dealing with old/bad gasoline?
 

Tomorrow I'm going to purchase a vehicle that has sat for around three years, so the fuel is obviously trash. Nothing was put in to the tank to make it stable, so what is my course of action here?

Can anything be added to the fuel tank to make the fuel at least burn somewhat? Maybe syphon the old crap out first the best I can then pour some fresh fuel in? :confused:

I would suggest you not drive the car since the gas is or must be varnish already. Well if the car does start and can be driven, just drive the car for a bit but then you must change the fuel filters and accumulators. Then give the car a full tune up and drop the tank to clean it out. This is what I would do If I was in your position.

You have a couple courses of action:

1. If the fuel level is low, you can probably dilute it with fresh fuel and this will probably get you going down the road. This is the quickest/easiest option, but not what I recommend.

2. Drain tank. Add fresh fuel. Considerably better than option 1.

3. Tow vehicle to somewhere you can work on it. Drop tank, drain and have professionally cleaned and inspected. Correct any rust issues. Reinstall, add fresh fuel. Most difficult and expensive option, but the best.

I used to have a Dodge Dart that sat for several years before I finally got around to putting an engine in it. I went with Option 1 at first. After ruining a carburetor and a number of fuel filters, I ended up going with option 3.

Edit: Two560Two, looks like we were typing at the same time.

Okay cool, looks like I'll be prepared to tow it back to the pad. I was thinking about draining it from the tank also.

Thanks

i think you will find
 

that the mb tank is made of much higher quality materials and will be less likely to have rust inside. i would take a tube and get a sample out of the tank to see what it looks like. if it isnt too bad you might be ok to just add fresh.

good luck

tom w

What color would it be if the fuel was bad? :confused:

i dont know
 

if the color changes or not. but i would get some out and look at it. it will under some circumstances get gummy. of course it will probably not smell like gasoline should either. i dont really know what i would be looking for, but if it came out good and liquidy then i would think draining it and adding more would be ok. if it were really gummy then i would prob take the tank off and get it cleaned. if it were, say, 1/3 full and good and liquidy and didnt seem too smelly i might just add gas and go for it.

good luck

tom w

I wouldn't try to judge the gas that's in there now; even if it's not totally varnish, the octane will have degraded severely, and I'd expect it to be at least partly congealed, so I'd take option 1 above off the table. The least I'd consider is draining as much as possible, adding good gas with a fuel system/injector cleaner and water absorber added as well, changing fuel filters, and running the tank through as fast as possible, doing a few cycles of this with repeated fuel filter changes. You might choose to add only 5 gal. or so the first time in case it doesn't work and you have to drain. Downside risk is that there's enough gum in there to give you trouble even with those measures, and the safest is obviously option 3.

Just drain it and fill with fresh fuel. It isn't worth the trouble trying to take a short cut and burn off the old fuel.

Even with fuel stabilizer 24 months is pushing it, after 36 its gone.

I'm going to syphon that old crap out, then refill. I'll let you guys know how it goes on Tuesday after I pick up the keys from the dealer. :D

Old gas smells....weird...It just doesn't smell like fresh gas...more like some sort of solvent you might use to clean your paintbrush with.

It can also gunk up the fuel line going to your fuel pump, and fill the little impellers in the fuel pump with crud. (just ask my 280SE) Oh, and you wouldn't believe what it can do with the in-tank screen!