How do I tell if I have gelled fuel?

[Randybee1]

Since I've only owned my B7100 for a month now and never having used diesel before. How do I tell if (or when) my fuel is gelled? Can I look in the fuel tank? or is it more of a "it won't start in the dead of winter" thing?
Thanks.. Randy B

 

[tomd999]

Hiya,

Easiest way is with a thermometer, if it's colder than say 40 and you haven't put treatment/anti-gel in it, it could be jelled.

Good news is that it's an easy fix for jelling, warm it up. (of course you may need to replace the filter)

My rule of thumb is that I don't trust that stations "winterize" fuel and I always treat when it's going to be lower than 40 degrees or if it's not going to be consumed within the forecast range.

There are plenty of treatment products to choose from, pick one and read the label.

Tom

 

[Z-Michigan]

The fuel will look literally like jelly. It may gel in areas you can't see, like the fuel line and fuel filter, then the symptom is not starting, or starting and dying.

I buy fuel from regular gas stations (not off-road diesel) and have had zero problems. I have had two diesel vehicles through two winters and both were fine without any fuel treatment, with temps as low as -10 F. I am in Michigan and it's reasonable to expect all stations here to sell winterized diesel. My tractor is in its first full winter and to be cautious I added Diesel Kleen to the tank just to be sure, especially since I haven't burned much fuel since September or so and therefore had some summer diesel in it still. If you have any doubts I would just add some anti-gel before you have a problem, and that should be all it takes. I would not use more anti-gel than the instructions say because they can be harmful to the fuel system in excess amounts.

 

[Randybee1]

Thanks guys.

 

[RalphVa]

I've never seen it, just experienced it. Started my Benz with a plug in heater outside at -22 F in Vermont. Started instantly (after glowing). Drove it down the road 2 to 3 miles. Stopped. Let it sit a minute or so. Started right up. Went another 2 to 3 miles. Stopped. Let sit a minute or so. Restarted and kept going this time. The filter on a Benz is located right up against the engine block (where it ought to be in my mind). Gelling will occur on the filter surfaces because that's where the most restriction is. I guess in really really cold weather, it would occur in the fuel lines.

It only takes about 0.15% of a fuel additive to keep it from gelling or about 25-50% kerosene or only about 10% gasoline (but this makes for a dangerous condition in the fuel tank). In my old Benz at that time, I had NOTHING added.

Gelling is caused by small amounts of wax forming in the fuel. The filter is the place where this wax can build a layer, enough to shut off fuel flow. I worked for 31 years in the lube oil industry. This is how we separate wax from oil, by filtering (aided by solvents in our plants). A good solvent for wax is kerosene.

Ralph

 

[danfromsyr]

one similiar symptom I recently had was a frozen fuel cap vent.

it was cold out, and acted like was gelling up.. but I KNOW it had a high dose of Diesel kleen in it, so shouldn't have been a problem.
fired up,
drove just around the garage and sputtered.. barely maintaining idle..
shut off and let sit a minute, engine heat can usually clear a frozen filter.
wouldn't run long

still puzzled because I know the fuel is additive added and it's only 12f out not subzero.

remembered seeing ice crystals on fuel cap while treating fuel previously.
removed cap and ran fine.. took cap into house and thawed it out.. reinstalled and ran fine..

Dan In Syracuse

 

[john_bud]

If you have a see thru filter housing, you will be able to see some floaters in there and after running for a bit and it stumbling etc, you will see what looks like snot on the filter.

I use Howes Diesel treat and it both prevents and helps eliminate gel from fuel. Was night and day better than PowerService.

Of note, once gelled, it takes a lot of heat to melt the wax and a lot of time. 24-48 hours in a heated area 65-70f.

jb

 

[robbieo11]

he asked how do i tell if i hve jelled fuel.
i have dipped a rod into the tank and move fuel around if it acts like wateru areok if it acts like STP oil treatment u know thick slow moving it is jelled

 

[jbrumberg]

On my old Ford and my new New Holland I had/have see through sediment bowls. When they are cloudy I am starting to gell and/or have already gelled up the ULSD. I use Power Service (White Bottle) with a "double shot" as recommended on the label for cold weather use. A lot of members also recommend Howes (I am going to try that brand next, but I have been satisfied with PS.). I use PS year round. I have not had gelling problems since I started using additives with ULSD. I like other members, buy my diesel from a local high volume regular gas station who appears to servce all the school buses and commercial operators. The recent price increase ~ $0.60 is reflective of all the kerosene they added this year as they did not trust the additive "mix" coming from their distributor(s). Jay

 

[Builder]

I use Howes, too. Ask your local big truck parts counter what they recommend.