Coolant in Fuel??

IntoTheWoods

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L2950 Tractor
Dec 28, 2021
6
2
1
Perry Utah
Tractor starts, runs about 30 seconds then putts out and dies. After sitting a while it’ll start again and do the same thing.
I assumed the diesel had gelled since temps just got real cold here so I
changed fuel filter and added a fuel additive to stop gelling a week ago but it still does the same thing now.
Today I pulled the fuel filter again and against the white background of the fresh snow, the fuel in the bowl appears to have green coolant in the fuel. I checked the coolant reservoir the coolant level is low. I know that it’s real bad news and what would cause coolant to get into the engine oil, but how would coolant get into the fuel filter bowl??

The color could also possibly just be from the additive or maybe is mis-colored from the new filter, but unless it’s some weird chemical reaction, I verified the “ Diesel 911“ is clear, not green.
I’m planning on fully draining and completely replacing fuel. I’ll also fill and mark the coolant level and start from there…any thoughts?
 

i7win7

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off road diesel, usually dyed red. if algae would expect some solid particles

sounds like algae or gelling
 
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IntoTheWoods

New member

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L2950 Tractor
Dec 28, 2021
6
2
1
Perry Utah
off road diesel, usually dyed red. if algae would expect some solid particles

sounds like algae or gelling
Definitely not red diesel, I havnt refilled my 300gal tank since Joe’s gas prices and have been lugging road diesel for the last few months. Against the bright white fresh snow, it 100% looks like antifreeze in the fuel. I just can’t seem to wrap my head around how coolant could get into the fuel tank!! Seriously the only explanation I can come up with is that maybe angry farmer Tom Nextdoor is still pissed about my horse eating his alfalfa through the fence and snuck over while I was at work and poured a gallon in the tank! (Only kind of joking)
 

IntoTheWoods

New member

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L2950 Tractor
Dec 28, 2021
6
2
1
Perry Utah
Run some fuel into a glass container and let it sit.

Water, antifreeze, gasoline will all separate.

Dave
Yes! I don’t know why I didn’t think of this… probably cause I was freezing my a$$ off and could only think about getting inextricably to a heater.
 

BruceP

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G5200H
Aug 7, 2016
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Richmond, Vermont, USA
When I had a diesel car, and drove all over the country, I noted that some of the diesel stations in the country had greenish colored fuel. I specifically recall "Flying J" truck stops having greenish color diesel.

As mentioned above.... put some fuel in a mason jar and let it sit. if there is antifreeze in the fuel, it will settle to the bottom.

I STRONGLY suspect your stalling problem is not the fuel itself.

Before a total drain of the tank... it would be trivial to connect up a fresh container of fuel to the inlet of the fuel filter and see how the engine runs. (essentially a hose from a can to the filter inlet)
Obviously, you would have to purge air out for this test to work.
 
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RalphVa

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Jan 19, 2020
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Charlottesville
Tractor starts, runs about 30 seconds then putts out and dies. After sitting a while it’ll start again and do the same thing.
I assumed the diesel had gelled since temps just got real cold here so I
changed fuel filter and added a fuel additive to stop gelling a week ago but it still does the same thing now.
Today I pulled the fuel filter again and against the white background of the fresh snow, the fuel in the bowl appears to have green coolant in the fuel. I checked the coolant reservoir the coolant level is low. I know that it’s real bad news and what would cause coolant to get into the engine oil, but how would coolant get into the fuel filter bowl??

The color could also possibly just be from the additive or maybe is mis-colored from the new filter, but unless it’s some weird chemical reaction, I verified the “ Diesel 911“ is clear, not green.
I’m planning on fully draining and completely replacing fuel. I’ll also fill and mark the coolant level and start from there…any thoughts?
Usually takes a bit longer if gelling is the issue. Gelling is just wax that forms on the fuel filter.

Use a hair dryer directed at the fuel filter to melt the wax. Then pack something around it and up against the engine block. Eventually, the engine block will keep the wax from gelling.

Happened once to me in Vermont in starting our old 220D Benz in -22 F. Had a lower rad heater on it. Started instantly but died a couple miles down the road. Let sit a minute or so. Restarted. Drove another couple miles. Did same. Then kept running. The smart Germans placed the fuel filter up against the engine block.
 

DustyRusty

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2020 BX23S, BX2822 Snowblower, Curtis Deluxe Cab,
Nov 8, 2015
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North East CT
Usually takes a bit longer if gelling is the issue. Gelling is just wax that forms on the fuel filter.

Use a hair dryer directed at the fuel filter to melt the wax. Then pack something around it and up against the engine block. Eventually, the engine block will keep the wax from gelling.

Happened once to me in Vermont in starting our old 220D Benz in -22 F. Had a lower rad heater on it. Started instantly but died a couple miles down the road. Let sit a minute or so. Restarted. Drove another couple miles. Did same. Then kept running. The smart Germans placed the fuel filter up against the engine block.
My first Benz was in 1968, and it didn't like cold weather. My last diesel Benz was a 1978 350SDL and it also didn't like extremely cold weather. By this time, Mercedes had developed a fuel heater that was piped into the heater line and had an outer wrapping of steel tubing that the fuel flowed through on the way to the injection pump. Problem is that by the time the engine was warm, you didn't need the fuel heater. By the time I was ready for another Benz, they dropped selling diesel's in the US, so I got a gas car. After that, they priced the cars for more than the value in my opinion, so I went to another brand.
 

armylifer

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Mar 26, 2013
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If it is gelled fuel, and it really does sound like it, follow RalphVa's instructions and it should start and stay running. Although I use Power Service products I do not like their Diesel 911 product. It is an attempt at a band aid that relies on alcohol as the main ingredient and sometimes does not work at temps below 0 degrees. Their winter formula (white bottle) has always worked for me. However, you have to add it before the temps drop or it will be too late after the cold temps hit. I have never had a problem starting when using it during fall until spring. It is cheap insurance for the money. I use about 50% more than they recommend just for added insurance in case we get colder than predicted temps.
 

RalphVa

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Jan 19, 2020
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Charlottesville
My first Benz was in 1968, and it didn't like cold weather. My last diesel Benz was a 1978 350SDL and it also didn't like extremely cold weather. By this time, Mercedes had developed a fuel heater that was piped into the heater line and had an outer wrapping of steel tubing that the fuel flowed through on the way to the injection pump. Problem is that by the time the engine was warm, you didn't need the fuel heater. By the time I was ready for another Benz, they dropped selling diesel's in the US, so I got a gas car. After that, they priced the cars for more than the value in my opinion, so I went to another brand.
Yeah, we went with VW diesel because it was the only stick shift. Got us nearly 7 years before they bought it back. Now on Mazdas. Near same mileage as VW diesel for the 3 at least.
 

Dustyx2

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BX22, M7060, Landpride RC-2512, Woodmax SB84
Feb 19, 2021
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NE Wyoming
If it is gelled fuel, and it really does sound like it, follow RalphVa's instructions and it should start and stay running. Although I use Power Service products I do not like their Diesel 911 product. It is an attempt at a band aid that relies on alcohol as the main ingredient and sometimes does not work at temps below 0 degrees. Their winter formula (white bottle) has always worked for me. However, you have to add it before the temps drop or it will be too late after the cold temps hit. I have never had a problem starting when using it during fall until spring. It is cheap insurance for the money. I use about 50% more than they recommend just for added insurance in case we get colder than predicted temps.
911 is for the "oh crap I'm gelled up". It's hard on fuel systems. Use that in a last resort type situation. The white bottle is what you use proactively to prevent the oh crap situation. I carry a bottle of 911 in the truck. It's been there for years and have never used it. I also carry a fuel filter.
 
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North Idaho Wolfman

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Tractor starts, runs about 30 seconds then putts out and dies. After sitting a while it’ll start again and do the same thing.
I assumed the diesel had gelled since temps just got real cold here so I
changed fuel filter and added a fuel additive to stop gelling a week ago but it still does the same thing now.
Today I pulled the fuel filter again and against the white background of the fresh snow, the fuel in the bowl appears to have green coolant in the fuel. I checked the coolant reservoir the coolant level is low. I know that it’s real bad news and what would cause coolant to get into the engine oil, but how would coolant get into the fuel filter bowl??

The color could also possibly just be from the additive or maybe is mis-colored from the new filter, but unless it’s some weird chemical reaction, I verified the “ Diesel 911“ is clear, not green.
I’m planning on fully draining and completely replacing fuel. I’ll also fill and mark the coolant level and start from there…any thoughts?
Your in an area where they change fuel from summer blend to winter blend, and thus the change in color.
Antifreeze and fuel will not mix, they will stay separated, so it's not antifreeze in the fuel.
Sounds like you have a restriction on fuel getting to the injection pump.
Pull the fuel line off at the side of the pump and check for flow.