Can someone explain what exactly happens when diesel fuel gels up

There is a percentage of parafin wax in diesel and when it hits its cloud point the wax solidifies out of the diesel. Wax don't flow real well.

 

i check temps where im going and add howes anti gel to tanks a day ahead to make sure its running thru the lines, never gelled up. in my experience -10 to -15 depending on wind chill is when you start having issues.

 

To PREVENT fuel gelling, you want to mix 50 gals of diesel #1 (kerosene) with every 150 gallons of diesel #2, or use a bottle of Antigel as per the instructions:



If your fuel has gelled or is beginning to gel, you must use Diesel 911 to REVERSE the gelling:



If your tanks get completely gelled up, you'll need a new set of fuel filters (once they gel up, they're pretty much junk), you might have to bring your tanks inside and treat them with a bunch of 911, and you'll be sitting there freezing your butt off priming the motor to get it started again.

The key is to avoid gelling in the first place. Watch the overnight temps, and if they start going below -12C (10F), start treating your diesel to prevent gelling. Straight #2 will begin to gel at approximately -12C to -15C, and if you don't have a motor with fuel return or an auxiliary fuel heater, you're screwed.

 

I usually like to put Howes in when fueling so it mixes well, but I already have full tanks. If I dump it in now, will road vibrations and the fuel sloshing around be enough to get a good mix?

 

Don't travel to areas that are -10 below... Stay in florida and you will never have to buy gel treatment...

 

It's best to add before fueling so it mixes in completely. If the motor has good return to the tanks, it'll mix eventually, but always best to start with it.

 

I tell you what happens.

You suddenly have a engine that wont maintain 1700 (Older iron the last time I gelled) and she falls down past 1000. You down shift. More of the same. You understand you are on the shoulder idling and that's all you can do. You have no power worth a dam. Pretty soon the filters have had enough and your engine must go off line. And that's that.

The last time I Gelled, the entire fuel tank and it's contents were dumped. The filters replaced. Fuel lines cleared.

Fresh good fuel added to everything. Maybe if you are lucky you have that roar of engine back up and ready to go out and work.

A side note. As long a portion of your return fuel to both tanks are hot you will never gel provided you do NOT turn off your engine below 10 above ever. You can go as low as -55 and not gel provided you run the hell out of the idle when sitting still. Fuel mileage is of no concern versus keeping two drivers alive.

 

Yes it will mix. Just idle. The fuel pump sends more fuel to the motor than it can burn. The excess returns to the tanks.

This process will mix the fuel in just a few minutes.
Good idea to make sure the treated fuel is in the fuel system, not just in the tanks.

The fuel in the lines will get colder faster than what's in the tank.
Good luck

 

Diesel Gelling
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Diesel fuel gelling happens when the paraffin usually present in diesel starts to solidify when the temperature drops. At 32 degrees, the wax in liquid form will crystallize and leave the fuel tank clouded. At 10-15 degrees, it will finally start to gel and clog the tank and fuel filters.