Slow Acceleration / Reduced Top Speed - 1981 DD 8V71

[neoneddy]

Re: moisture in the air.

I think you're both right.

1) yes air condensing will precipitate water, how much?

2) how much enough to matter?

There is roughly 1 pint of water in 1000 cubic feet of air at 100% humidity at 70 degrees.

Using 7.48 gallons per cubic foot and let's assume an empty 150 gal fuel tank for worst case scenario, we get 20 cubic feet of air.

If my math is right , and we condense all the moisture out of the air we get .32 oz of water.

This is assuming no air is ever exchanged.

Now if you're a working charter bus and you full up in the morning, .32 ounces is now 10 ounces after 30 days.

I don't think a few moves of water is enough in a tank.  However using this math and you have all the hot moist air coming into a holding tank at a filling station, water can quickly build up there, but I hope they are separating it.

[chessie4905]

If you get fogged up windows on the inside of your car, either the carpet is wet or the heater core is seeping coolant at a seam. If it is hard to evaporate with defroster, it's coolant. If the carpet is dry and heater core isn't seeping, then pull the carpet; the padding is wet. Leave it that way and car will smell musty eventually. Have seen that several times over the years.
I think water in the fuel systems is pretty remote anymore. Since they required fuel tanks across the country to be replaced, water and dirt is mostly a thing of the past. However conversions with water and crap in the fuel tanks is common. Owners of older coaches should thoroughly clean their tanks. The lower cost ohf fuel filters will more than pay for it.

[richard5933]

You can easily rule out water in the bottom of the tank. Either crack the drain valve is there is one and take a sample, or put some of this on the end of a long stick and insert till you hit bottom. The paste will let you know instantly if you've got water in the tank.

https://www.amazon.com/Kolor-Kut-Ounce-Water-Finding/dp/B00905UC5E/ref=sr_1_1?hvadid=241900463166&hvdev=c&hvlocphy=9018822&hvnetw=g&hvpos=1t1&hvqmt=b&hvrand=1119095459885555116&hvtargid=kwd-10010660&keywords=water+finding+paste&qid=1552252009&s=gateway&sr=8-1&tag=googhydr-20

I wish they had a gizmo on our tanks like small planes have to quickly take a fuel sample in a glass jar to check for contaminants.

[chessie4905]

They do Richard. It's called a drain plug. Just unthread it and quickly reinstall it. If you drop the pkug, there won't be any water in the tank.🤣

[HenryTX]

I'm expecting that my diesel tank is dirty and possibly coated with a healthy layer of microbes.

However, I don't have the proper facility/equipment to remove the 130 gallon tank and clean the inside of it.

Any ideas on where I might be able to take it to have it done professionally?

[richard5933]

They do Richard. It's called a drain plug. Just unthread it and quickly reinstall it. If you drop the pkug, there won't be any water in the tank.🤣

I guess a drain plug would qualify as a gizmo. I should have been more specific - a handy gizmo.

Since the tank's drain plug is not that handy, what I usually do is drain a little from the primary fuel filter into a class jar to check the fuel.

[buswarrior]

Condensation needs a sufficient change and/or differential of temperature, along with air laden with an appropriate amount of water.

The air, fuel and the tank are all the same temperature when they are sitting, any change, they change together.

And in a sitting fuel tank, very little if any meaningful air exchange.

A very slick lie was told to us, repeated over and over, a lie that "makes sense"... we believe it because it sounds good, and we can't be bothered to test the theory... Someone who "knew what he was talking about"... someone who had a vested interest in blaming the water on imaginary sources, or blaming the owner for "not keeping the tank full" to cover their own tracks...

And any water found in the fuel tank immediately becomes the proof, no matter where it really came from.

A fuel tank rigged up in the storage shed for the winter, the summer, whatever, extend the fuel filler pipe to a sheltered outside location to confirm outdoor air, and be amazed that it stays dry for as long as you try.

Same as the one in your coach.

happy coaching!
buswarrior

[buswarrior]

I guess a drain plug would qualify as a gizmo. I should have been more specific - a handy gizmo.

Since the tank's drain plug is not that handy, what I usually do is drain a little from the primary fuel filter into a class jar to check the fuel.

Trouble with that, you are only checking the fuel at the height of the fuel pick-up...

Water and crud lies on the bottom.

Pull your drain plug and know the truth.

It is a fun adventure the first time, especially if the plug gets away from you.. you'll be fine, expect to get splashed, expect to fumble the plug, have a big enough pan, don't let the plug bounce under the coach...

happy coaching!
buswarrior

[buswarrior]

HenryTX,

Look up the marine folks.

Fuel polishing / fuel tank cleaning service is what you need.

Negotiate and shop around. Go to them, come to you.

happy coaching!
buswarrior

[sledhead]

I have a 400 gal. diesel farm fuel tank that sits outside under a roof and posts . It goes from full to almost empty and full again . I check it a couple times a year with the water grease stuff to see if there is any water in it and in the 20 years I have been using it there has never been water in it . I guess my bulk diesel guys give me the good stuff ?

we get lots of temperature changes and snow and ice and rain

I agree if you have water in your fuel someone put it there

dave

[Dave5Cs]

There is no plug on my 5C. I have looked and asked on all boards but no responses, does not show one in any manual I have or parts book etc. 

[eagle19952]

there is water finding paste.
I fueled a Gulf-Stream jet once. <OK more than once>
They took a fuel sample in a Waterford crystal bar glass. They gave me the glass.
Point, water in fuel is easy to determine.
Filters contain it.

Ditto, get help.

Water condensation is the biggest piece of bullshit mythology ever perpetrated on vehicle and boat owners.

Nothing but a lie to cover up the water in the fuel from the pumps.

Since all the advances in fuel storage regulations, decades ago, we don't often get water delivered into our tanks via the pump like the old days. And when we do, someone introduced the water, it didn't "grow" there.

Believe in whichever false prophets you want, if you are really committed, I would love to see a test done to "create" water in a proper vehicle fuel system. Some decent measure of scientific method and the ability to reproduce the results please.

Happy coaching!
Buswarrior

[buswarrior]

There is no plug on my 5C. I have looked and asked on all boards but no responses, does not show one in any manual I have or parts book etc. 

Interesting... on the bottom of the face of the tank, with the body panel in front of the tank removed?

Maybe Brian Evans has an answer?

Happy coaching!
Buswarrior

[Ed Hackenbruch]

Dave on my 5A it was behind a little door/flap just behind the entry door down low.

[Geoff]

If the problem is sporadic, it could be something floating in the fuel tank that only plugs up the fuel pick up at random times.