Bad Gas after storing 6 months??

[ColoradoCal@gmail.com]

First time owner of a 2021 Thor class B+ with Ford Transit 350 Eco-boost AWD 10-speed Engine. Just got out of storage after 6 months and it barely runs. Shall I assume it's bad gas? If so, it's 3/4 full. What should I do, let it run, or try to get it drained somewhere? Thanks!

[Pete'sMH]

I’d guess it might be water in your gas. Unless your tank is full during storage you can get condensation inside the tank and the ethanol in modern gas holds it in suspension so it doesn’t burn very well. If it’s running dreadfully you might have to drain it although I don’t know how you’d collect and dispose of it. But if you don’t have a check engine light and it runs “reasonably well” and especially if it was running well when you stored it it probably is ok to drive it a bit and see how it goes. Once you burn it down to a third full or so a fill up with fresh gas probably will help. But you’ll really want to get the old stuff used up. Good luck.

[Travelin' Texans]

Originally Posted by ColoradoCal@gmail.com

First time owner of a 2021 Thor class B+ with Ford Transit 350 Eco-boost AWD 10-speed Engine. Just got out of storage after 6 months and it barely runs. Shall I assume it's bad gas? If so, it's 3/4 full. What should I do, let it run, or try to get it drained somewhere? Thanks!

Depending on tank size pour in a can, or 2, of Seafoam.
In the future add fuel stabilizer to a FULL tank of fuel before storage.

[ColoradoCal@gmail.com]

Thanks. Rookie mistake!

[Chateau_Nomad]

I use MARINE GRADE (the blue stuff, NOT the red) STA-BIL before storage, OR if the rig is going to sit for any length of time.

Ethanol will separate and moisture will condense in your fuel if it sits long enough. The blue STA-BIL is supposed to counteract both of those issues. I have used it for three motorhome storage periods of 6 months each, and had zero fuel problems.

I would try pouring the appropriate amount in your tank and let it sit overnight... might help. It's better to prevent in the first place though.

I have heard good things about Seafoam too... I've used it as a "de-carbonizer" and carb cleaner on my mowers.

[Judge]

I have a Super C so I run diesel.... but I have several gas vehicles that can sit for many months. I almost always run the tank down and then fill with Ethanol free gas when they are going to sit.

If I can't get Ethanol free for some reason, I add Ethanol Shield to the tank.

[sportcoupe]

From The Google:

Search - gasoline shelf life

three to six months
Regular gasoline has a shelf life of three to six months, while diesel can last up to a year before it begins to degrade. On the other hand, organic-based Ethanol can lose its combustibility in just one to three months due to oxidation and evaporation. Tracking the age of the fuel in your tank can be a challenge.

[Bob Denman]

Your fuel isn't "bad": it just got old!

[GTM41261]

Today's fuel has a self life of around 90 days. Most all fuel has 10% ethanol alcohol. Alcohol is a big magnet for water and can pull it out of the air. It takes as little as one percent water in your fuel for it to go into what's called phase separation. This means that the water alcohol and fuel separate, with the water and alcohol staying in the bottom of the tank. Signs of phase separation damage to your fuel system is rubber fuel lines that have dissolved from the inside.

It is a very good idea to add a fuel conditioner/stabilizer to any vehicle that will be sitting for more that a month. Adding fuel conditioner to bad or old fuel will not magically make it better. Once milk Sours there is nothing to add to it to make it fresh again, same with fuel.

[Sappy2]

I doubt it is bad fuel unless it is stored in real high ambients. Add some stabilizer, top off the tank with good grade fuel, drive it. I am not sure what "runs bad" means so maybe a bit more description would help. Usually, poor fuel quailty results in hard start, poor idle. Take it for a run after doing tank top off and additive. There may be something else going on - not sure.

[Chateau_Nomad]

Originally Posted by GTM41261

Today's fuel has a self life of around 90 days. Most all fuel has 10% ethanol alcohol. Alcohol is a big magnet for water and can pull it out of the air. It takes as little as one percent water in your fuel for it to go into what's called phase separation. This means that the water alcohol and fuel separate, with the water and alcohol staying in the bottom of the tank. Signs of phase separation damage to your fuel system is rubber fuel lines that have dissolved from the inside.

It is a very good idea to add a fuel conditioner/stabilizer to any vehicle that will be sitting for more that a month. Adding fuel conditioner to bad or old fuel will not magically make it better. Once milk Sours there is nothing to add to it to make it fresh again, same with fuel.

Not entirely true... you can make buttermilk from soured milk!

The issue with un-stabilized gasoline is that the water separates and settles to the bottom of the fuel tank when left undisturbed for long periods of time. Since fuel is drawn from the bottom of the tank during engine operation, the water is the first thing sucked out... NOT good.

Obviously dropping the fuel tank and draining off the water would be the ideal solution. But NOT very practical. A more practical method would be to agitate the fuel in the tank, causing the water to temporarily mix with the gasoline. It's likely the amount of moisture in your gasoline NORMALLY doesn't cause immediate issues because it is kept mixed with the gasoline and passed relatively harmlessly out the tailpipe. This mixture is obviously leaner, but today's engines have sensors to adjust for that. Allowed to sit several months, the water sinks to the bottom.

Alcohol and water is readily miscible (mixes together). By adding an alcohol based additive to the gasoline, the alcohol will readily mix with the water in the bottom of the tank. Short of draining the water logged gasoline, using a combination of agitation and a fuel additive will give a MUCH better result of getting the fuel burned.

Bottom line... I would suggest adding something like HEET water remover additive and driving your rig to burn the water logged gasoline - gradually adding fresh fuel when possible. Although not a PERFECT solution by any means, it will eventually clear the water from your fuel system.

I'm betting you'll use a fuel stabilizer NEXT year...

Good luck!!

[ducksface]

Drive/tow the vehicle to the closest dealer(if you're under warranty or independent shop if you're not under warranty) who can actually diagnose.
Do whatever the nice man says needs done.



Too many wrong/laboratory-based fuel statements have been made here.(I can't find any reason to assume its fuel related other than the op speculates)

This Isn't an opinion type situation..
This is a
Have someone knowledgeable put hands on it
Type situation..

The op description lacks enough information to speculate.
You could have a rat nest in your intake for all we know.
Rat could have chewed a wire and you're in limp mode.
You could have sucked up a Wal-Mart bag.

Then there's that whole
'Little blue cap' thing.

[Travelin' Texans]

Originally Posted by ducksface

Drive/tow the vehicle to the closest dealer(if you're under warranty or independent shop if you're not under warranty) who can actually diagnose.
Do whatever the nice man says needs done.



Too many wrong/laboratory-based fuel statements have been made here.(I can't find any reason to assume its fuel related other than the op speculates)

This Isn't an opinion type situation..
This is a
Have someone knowledgeable put hands on it
Type situation..

The op description lacks enough information to speculate.
You could have a rat nest in your intake for all we know.
Rat could have chewed a wire and you're in limp mode.
You could have sucked up a Wal-Mart bag.

Then there's that whole
'Little blue cap' thing.

And the other issue, F....O....R....D!

[GTM41261]

I spent way to many years dealing with fuel issues in my past life. I have sat in meetings with fuel companies and additive companies. Fuel starts going bad the minute it leaves the refiner. 90 days is considered to be the standard before the octane starts dropping off. Add alcohol to the mix and now you have a big sponge for any water. A fuel system vented to air like in the marine industry is by far for of an issue that air tight systems like in automotive. Adding fuel conditioner to old, stale failed fuel will not bring it back to fresh you are just throwing money down the drain. The only time adding a fuel conditioner will help is to add it shortly after you fill up, then it may stay stable for up to a year.

[ducksface]

Thanks for mentioning the closed system.


Will someone post a link showing how much water a 90% dilution of alcohol can absorb...through a closed system... while using only slight thermal changes as an agitator?

Bonus:
To remove alcohol from modern gas, in small lawn-mower size batches:

In a clear container add a pint of water to a gallon of gas.
Stir.
Wait an hour just for good measure.
The water Will bind with the alcohol.

Siphon off the water/alcohol solution.(it's now very bad vodka)
Remeasure the siphoned concoction.

You now have fuel that is 99.9% alcohol free
You now know how much alcohol was really in the fuel.

[Lt Keefer]

If you don't want to take it to a technician for servicing then run the current fuel out. I have had good luck with Lucas fuel treatments when I have had the misfortune of getting some bad fuel.

[MJC62]

Originally Posted by ducksface

Thanks for mentioning the closed system.
I was just too exasperated.

Will someone post a link showing how much water a 90% dilution of alcohol can absorb...through a closed system?

Condensation is the culprit. I would think absorption of h2o in a closed system would be non existent. Condensation is minimized with a full tank.
Even fuel stored with a stabilizer will get stale. My experience has been the fuel that was in the tank during storage even with a stabilizer doesn't seem to perform like fresh gas.

The OP should determine if the engine is indeed suffering from old stale fuel "barely runs" is too vague a description to properly analyze the problem.

[ducksface]

Correct.
It can only condense the water that is in the air in the tank.
50 gallons is 6 cubic feet(close enough for math here.).


1 cubic foot of air at a standard temperature and pressure weighs approximately 0.08lbs

Max water a cubic foot of air can hold is one pound(a pint/16 ounces volume=16 ounces weight for water) per 500 cubic feet of air.

The most possible water that can be in your empty fuel tsnks air is
8cubic feet/500cubic feet= 1/60th+- of a pound.
0.25 ounces=6 teaspoons to an ounce...=1/2+ teaspoon MAX of water in your half full gas tanks atmosphere.

Punchline:
If your half tank of gas sucked the air to 0% humidity from 100% in your closed system You'd have 1/2 of a teaspoon of water added to 25 gallons of gas.

Closed system.
Leave the gas cap off to see different results.
Maybe 4 times worse for a total of a tablespoon of water added to your 25 gallons of fuel


Water is 8lbs+ per gallon.
(Thus My rounding of numbers due to 2, 6, 8,16, .08, 60, 1/60th, pints, ounces, pounds.)







It takes 500 cubic feet of air to hold a pound/pint of water at 60%(call it 50%for ease of remembrance) humidity.
That takes an empty 4500(call it 5,000 so its easy) gallon tank to have a pint/pound of atmospheric water. (that's 1:/60,000ish)



Bonus.
Open atmosphere burning a gallon of gas will/might/can generate 6+(maybe 8) gallons of water.

How?

(My math is from memory of things I don't particularly care about. I could be off on occasion, but nothing that changes the gist.)
And
I am often wrong.

And why did everyone join the
'I think'
Instead of thinking?

The op said nothing involving an expert opinion.
Wild guess gone wild.

[ducksface]

secret squirrels.

This is up for trade.
Be the only one on your block....

[Oneilkeys]

In Florida I can purchase non-ethanol fuel and I fill up my tank with that as well as 2 cans of Seafoam if I am going to store my RV (or my vehicles) for any length of time.