Help - Cloudy Fuel

[jarhead]

Originally Posted by bret

This is #2 Diesel just a little past cloudy Ever since the government changed to the ultra low sulfur fuel we have experienced serious problems with this new fuel. Back before they changed the chemistry the #2 would cloud around -15 F now we get complete filter blockage at 5 F. I hope that our LL or auto 91 does not do anything like this.

Wow... you need some Power Service white! Was recommended by many TDI web forum members from Canada (eh?), and I never had a problem with fuel gelling or waxing when I owned my '96 Passat TDI, even in single-digit temps.
[/off topic]

Back on topic:
Drain the tank through a large coffee filter, and see what (if anything) gets filtered out. Refill the tank, and resample after a minimum of 24hrs to see if you get the same cloudiness.
As already suggested, store the "suspect" gas and use it for lawn mower, snowblower, and other non-critical outdoor equipment.

[bits]

As suggested by forum users, I drained all the fuel from the tank through a coffee filter, flushed the tank a couple of times with about a quart of clean fuel, and refilled the tank. I let it sit for about 42 hrs, through temperatures ranging from 23deg F to 36deg F. I then took a sample; the fuel is now crystal clear. I plan to check the fuel filter screen, and clean the filter/lines as needed. After that, I'll give it a good long ground run. If all indications are normal, I'll take it up for a test flight above my home field.

[RWingMech]

Originally Posted by bret

This is #2 Diesel just a little past cloudy Ever since the government changed to the ultra low sulfur fuel we have experienced serious problems with this new fuel. Back before they changed the chemistry the #2 would cloud around -15 F now we get complete filter blockage at 5 F. I hope that our LL or auto 91 does not do anything like this.

Looks like the frame filter off a Ford 6-leaker - never had that happen in the 14 years and the 290,000 miles when I owned one.

On a more serious note - a friend of mine routinely fills his Cub at a nearby airport then drains out 5 gallons to have extra fuel on hand. Once he had 5 gallons turn from blue to white in the jug after a couple of weeks of sitting. We never figured out what caused it, needless to say it when it the H tractor and not the plane.

[thefreddy]

I put 100LL in clear plastic racing fuel tanks. After 4 months the fuel lost its blue color. Has anyone else experienced this phenomenon?

[Jpm757]

Safest bet would be to drain the ENTIRE fuel system, including the carb fuel bowl. Flush the system with clean fuel with the carb bowl plug removed, clean all screens and go from there.

[N941WR]

Originally Posted by Jpm757

Safest bet would be to drain the ENTIRE fuel system, including the carb fuel bowl. Flush the system with clean fuel with the carb bowl plug removed, clean all screens and go from there.

You are replying to a two year old thread.

[N941WR]

Originally Posted by thefreddy

I put 100LL in clear plastic racing fuel tanks. After 4 months the fuel lost its blue color. Has anyone else experienced this phenomenon?

Different issue than w thread.

We're your tanks stored in the sunlight?

[Caveman]

"Water Contamination
? Water is the most common contaminant found in aviation fuel and falls into the following two categories
o Dissolved Water (Water in Solution)
 Does not present a risk to aircraft engine operation
 The amount of water that fuel can hold in solution is a function of the fuel temperature
 The higher the temperature of the fuel, the greater the potential concentration of dissolved water
 As fuel cools, it can hold less water in solution and the water condenses out of the fuel as free water.

o Free Water (Undissolved Water)
 Any water that is not dissolved in the fuel
 Accumulates at low points in fueling systems and settles to the bottom of tanks because it is heavier than fuel

Sources of Free Water
? Movement of ?water in solution? into ?free water?
? Introduced into the fuel from outside sources
o Condensation of water vapor (humidity) in any air space inside fuel storage tanks, piping and filter vessels

o Fuel handling equipment integrity issues (leaks in fittings, fill caps, manways, etc.)
o Water laden transport deliveries
1.1.2 Risks of Free Water
? A water slug reaching the engine could cause performance issues
? At high altitudes (colder temperatures) free water can form ice crystals which can plug aircraft fuel system filters and fuel control units
? Water enables microbial activity in fuel storage
? The presence of water in a storage tank can cause the FSII additive in jet fuel to migrate out of the fuel and into the water, at the fuel-water interface
1.1.3 Detecting Free Water
? Field Testing
o White Bucket Test ? Free water in fuel may be observed as a hazy/cloudy appearance, water droplets, or bulk water see Section 5.5 Fuel Quality Testing ? White Bucket Test
Note: Free water is typically not visible to the eye until it reaches levels greater than 30 parts per million (PPM)
o Free Water Test ? ATA Specification 103 recommends a maximum allowable limit of 15 PPM downstream of filtration"

Unquote...I suspect you are seeing dissolved water. I would keep your fuel tanks topped off after each flight so water does not condense from the airspace above the liquid level in your tanks if you don't already follow that practice.

[RVDan]

Gasoila AP2 will detect water in fuel. Search Amazon it?s cheap.