Old gas in vehicle questions

[Profreedomokie]

The big concern would be rust in the tank. The old Jaguar I bought had rust in the tank, so I ordered kits from Eastwoods to clean it out and seal it. I found the tank had too many baffles in it to be sure I could reseal it. So, I bought a new tank and didn't use the kit.

 

[swampratt]

Gas can get stinky and sometimes it is fine and other times it makes a mess in a fuel tank.
My 47 dodge sat for 4 years with 7-11 brand 91 octane gas in it.
No issues at all, no rust.

Friends Ford Taurus using OnCue 100% gas sat for the same amount of time and that gas created stalactites that were red in color like rust.

It was not rust but some kind of something created by evaporating fuel.
Had to wipe the entire tank clean with rags.

Then there is the stuff that sat for a very long time and became more like syrup and left a honey coating in the tank some of those cleaned up and some that cleaned up ended up with a bunch of small pin holes in the tank.
Did not leak until all the stuff was cleaned out.

I do know this though for all my daily drivers I will not put good gas in dirty tank.
Power wash and lots of scrubbing. Or a new tank.

 

[SoonerP226]

This is the advice I've been given in the past by an auto mechanic.

When I let my Lincoln sit for a couple of years (long, boring story), I had to replace the fuel pumps because there was so much water in the tank that it rusted the metal parts of the pumps. It didn’t even smell or feel like gasoline, and I’d bet that if I’d set a match to it, it wouldn’t have burned. Fortunately, it was a plastic tank, so the tank itself was fine, but the pumps were an unholy mess.

 

[montesa]

How long did it set?

I heard 5 years.

 

[cowadle]

I had two engines bend push rods from old gas. The varnish made the valves stick. It was a mess to clear up. Seafoam made it worse and b12 helped

 

[User_3155]

If it has sat, it probably has more problems than just bad gas. If you do it right and drop the tank, you can check that box and know it ain't that and move on to the next. Sucks, but I'd drop it.