So I now own 2 diesels this year and was curious, I always hear stories of diesel gelling up. If it does gel will it ungel with heat? that is to say if I have a tank full of diesel up north for winter that gels when I try to start my rig in the summer with the fuel be good to go or once gelled always bad?
In big rigs our fuel systems returned excess fuel to the tanks. Having passed through the pump, it would have been warmed by the engine which helps to prevent gelling. Modern diesel is fortified by with additives poured into the tanks in winter. At 25º F and below we always idled the motor during breaks to keep the fuel warm. Here is a piece for your light reading: "Diesel fuel is pretty awesome when you think about it. Basically, when crude oil is refined and made into usable oil products (like petroleum, aka gasoline, for cars and other power) diesel fuel is a byproduct. Diesel fuel runs huge ships, (older) submarines, trains, trucks, and cars. In smaller cars, diesel fuel allows for great fuel efficiency. However, there are some issues with diesel fuel.
"One of the main downsides of diesel fuel is that it doesn’t play nicely with cold weather. When I say it doesn’t play nicely I mean that cold weather can kick its butt. When temperatures drop diesel fuel can form waxy solid crystals that clog fuel lines and fuel filters. Not only does this cause engines not to start (or to start and then die), it can also require major repairs if things get bad enough.”
"One way to avoid diesel fuel from crystalizing (or gelling) is to use an anti-gel fuel supplement. Diesel fuel anti-gels are simply added to the fuel (just drop it in the fuel tank). Anti-gels drop the freezing point of diesel fuel so that it is less likely to freeze in cold temperatures. (**IMPORTANT: do not confuse diesel fuel conditioner or diesel fuel supplement/additive with anti-gel. Diesel fuel conditioner or a supplement like CleanBoost Maxx WILL NOT prevent diesel fuel from freezing).”
“So, when do you use anti gel?"
"Temperatures below 32 degrees Fahrenheit (0 C) Smart to use some anti-gel as temperatures approach what we call the freezing point. Generally you will be able to use a smaller amount of anti-gel the warmer (or less cold, as the case may be) the temperatures are. Follow instructions on the bottle of your anti-gel”
"Temperatures at or below 0 degrees Fahrenheit Basically, you should just use more anti-gel as temperatures get colder. Also, check your manufacturer’s (of your engine) suggestions on heating your engine block at extremely cold temperatures.”
"Fast drops in temperature If the temperature is set to plummet rapidly it is best to use more anti-gel in preparation. If temperatures are already low, it may be too late. Preparation is important. Anti-gels will not hurt your diesel fuel or your engine so when in doubt, use a bit more.”
When you fill up Use your diesel fuel anti-gel every time you fill up during the winter. Try to remember to add the anti-gel before pumping the fuel. This will help ensure a good mixture of the anti-gel throughout the fuel.
Engine starts to run rough during cold temps This could be a sign that your fuel is gelling. Add anti-gel ASAP. If your fuel lines get completely clogged your engine will stop and chances are you could be getting cold really fast. (Side note: if you live/travel/work in areas where diesel fuel anti-gels are necessary ALWAYS make sure to have emergency kits that include some source of warmth, food, water, and a blanket.”
Thanks Rick, I guess my question now is if I have a diesel that sits all winter will the fuel ungel in summer?
Yes it will "UN-Gell". Diesel fuel starts gelling at around 20 deg. What s gelling ?, it's when the paraffin molecules in the fuel change from liquid to solid and get caught in the filter. Most fuel suppliers/stations start selling "Blended" fuel as the weather starts getting near freezeing in the fall, what they do is blend perhaps 10% number 1 fuel with 90% number 2, as the ambient temps drop here in the northern states the ratio will increase the #1 fuel. Now that being said!, your thinking "why not remove the parrifin from the fuel and avoid this PIA", well Parrifin is what makes the power in your Diesel engine!, try running straight #1 in the summer and you will have NO power!. Along with blended fuel, there are additives you can add to further prevent the gelling process, Diesel 911 is the local favorite around our area, the KEY to this is adding it BEFORE the ambient temp gets below 20 deg. NOT after, as once the parrifin starts to solidify you cannot reverse this process unless you warm the fuel to over 20 deg...... So Schimmms, now you have a choice, if you fill your fuel tank with winter blended fuel, your performance will suffer in the summer if your still burning your winter supply when summer arrives, and like wise if your burning summer fuel in the winter, you face the dreaded gelling issues. AND, now we are forced to use "Bio-Diesel", that adds another set of problems, the Soybean squeazings like to stick to the sides of your fuel tank in the summer (scum layer) and fall off when the weather gets below 10 deg, this crap then plugs up your fuel filters, it looks like thin strips of liver in the filter, in fact at work we call it liver, LOL. I have several pieces of diesel equipment, I do not store more than 10 gallons of fuel in a storage tank to avoid the summer/winter issue and this also avoids the bio-diesel problem. If I have a big project I'll fill a 55 gallon drum with the fuel of the season for that work. I have had many diesel service trucks, I change fuel filters at every oil change, use blended fuel when in season and have Never been stranded on the road from gelled fuel using NO fuel additives.
Forgive your enemy, but remember the bastards name. (Scottish proverb)
Thanks Lee. Between you and rick I feel comfortable making choices now. I have a 55 I’m going to get filled with off road diesel for my equipment up north. I added some winter mix to my crawler before I tarped it for winter. Just got the duece though and am guessing he filled it in October so I’ll top her off tomorrow with winter mix.
Another tip--------storing your truck with a low tank will help it sweat or form moisture inside. Add your power service or 911 and fill up with blended fuel. That helps keep the water out. Your canister type filters have a bleeder. The first has one in the bottom. Open it up and drain a little from time to time. I bought and installed a freeze plug heater in my deuce. If I need it in the cold, I'll plug it in for a hour or two before starting the engine. Way better for your diesel to not start it up cold like that. Run it a while before you put a load on it. If it's hot and coming off the highway, also let it run a bit and cool down at a idle before shutting it off. Drain your air tank too. A solariser that trickle charges your batteries when in the sun helps also. Before starting your truck after it's sat a long period, it's recommended to leave the fuel shut off and spin it over with the starter. This checks for a hydro lock or leaking antifreeze into your cylinders. If it has a leaking head gasket and you start it full of water, there goes the engine. Ok, roll coal buddy!
On the dash, left of the steering wheel. Two cable pulls. One is throttle, the other is fuel shut off. The cable goes to the injector pump and moves the fuel shutoff arm. Pull is off. Should be labeled on the T handle!