Totally not thinking I put 1 Gallon of DEF in the fuel tank, i think it was the dumbest thing i've done in my 67 yrs on this planet, anyway I immediately disconnected the battery and hope just the tank and fuel pump needs replacing or cleaning, have to wait til Tuesday as nothing is open now. Just so used to opening the green cap, I think GM should have separated the two.
DEF in fuel tank
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Bummer. We’ve all made dumb (and costly) mistakes. I know i have.
Hopefully all you need to do is to drain the fuel tank and change out the fuel filters. The dealership could do that for you if you’re uncomfortable with it.
Hopefully all you need to do is to drain the fuel tank and change out the fuel filters. The dealership could do that for you if you’re uncomfortable with it.
I'd have a problem with 18 gallons of diesel fuel to dispose of and there is no drain on the fuel tank, have to remove tank.
I actually like the def fill on the canyon much better the my dads l5p. It sucks having to fill it under the hood. Maybe you can pump most of it out through the filler neck with a fluid transfer pump or old inline fuel pump. I think the def will separate from the diesel, I just don’t know if it sets on bottom or top.
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128 Posts
GET ABOUT 6 FEET OF A SMALL WATER HOSE. INSTERT 1 END INTO THE TANK ABOUT 2-2.5 FEET. CUT A SMALL HOLE IN THE SIDE OF THE OTHER END AND BLOW PRESSURIZED AIR THROUGH IT. ONCE FUEL STARTS COMING OUT, IT WILL CREATE A VACUUM AND PULL MOST OF THE FUEL FROM THE TANK
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128 Posts
Blow out the end of the house to create the initial vacuum
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Had it hauled to the local chevy dealer and they had to take tank off and flush, Total cost $861, if I had turned on the ignition it would have been a whole lot more.
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Ouch. Glad it’s fixed.
Betcha won’t do that again
Betcha won’t do that again
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290 Posts
RockcrawIer got it just right.
I think you made a wise decision. I also admire you posting this. From your gutsy admission we now know that there's at least 10 who did this, cussed and looked around to see if they were being watched.
Just too bad the tank doesn't have a sump drain, a la private planes. Since the DEF is probably heavier than the diesel, and probably also has little affinity for it, you might have been able to get away with draining it that way.
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25 Posts
Hope you didn't start the truck with the def fluid in the tank...
No, I immediately knew I screwed up and pulled the fuel pump fuse and relay and had it hauled to the dealer.
add me to the loser crowd who did this. late afternoon, tired, added a gallon and then realized it went into fuel tank, DOH! truck had been off for several days and i didn't start it. called local shop who towed it away next morning. told me it would be a simple job to drain and blow out lines. now they tell me my "water in fuel" light is on so they're replacing the fuel filters and i may have to replace the sensor. they asked if this light was on before and i told them never. so, my question is what caused this? i assume they turned the key to get it from park to neutral and that probably powered the fuel pump for a few seconds. they assure me the def couldn't get past the fuel filters. is that true or could they have just ruined my engine?
When you turn the key on the lift pump in the fuel tank will power up, they should've known this. They should do the right thing and eat the labor and filters for their screw up. The only way that the contaminted fuel could have made it into the filter box is them turning the key on. There is a fuel return line to the tank what's unknown, is the return prior to the HPFP or after it? meaning that the contaminated fuel made it's way into the HPFP and if so that's really bad. If the supply and return line doesn't present contaminated fuel into the HPFP then you're okay. The lines will still have to be purged once you actually know where they go.
thank you for that explanation. is hpfp high pressure fuel pump? i know they plan to purge the lines but now i am trying to figure out if there is anything else that needs to be done to ensure no def gets or got past the fuel filters, which they are replacing.
just got back from the mechanic. he said he pumped it out, changed the filters, drove it and redrained the seperator and nothing other than diesel came out. but, driving it 2 miles home just now the "water in fuel" warning came on twice. he told me if it did just to drain the separator, which i can do.
but, is this an indication that there is still def in the system or that the sensor got wet with def and is now faulty? what pisses me off is that i offered/asked to pull the fuel pump relay and the owner of the shop emphatically told me not to do anything. then, i am sure they turned the key to put in neutral to pull it on the truck and that's when the def circulated.
any advice as to what i should do now is appreciated? be a hard ass and make them change the filters again at their cost this time? change them myself and not drive it til i do? is it already too late and damage is being done? it runs just like always and i'd heard that def contamination will be noticed right away and it will run bad. but, what if there is still some def in the bottom of the tank and that just keeps coming into the separator, hopefully not beyond?
but, is this an indication that there is still def in the system or that the sensor got wet with def and is now faulty? what pisses me off is that i offered/asked to pull the fuel pump relay and the owner of the shop emphatically told me not to do anything. then, i am sure they turned the key to put in neutral to pull it on the truck and that's when the def circulated.
any advice as to what i should do now is appreciated? be a hard ass and make them change the filters again at their cost this time? change them myself and not drive it til i do? is it already too late and damage is being done? it runs just like always and i'd heard that def contamination will be noticed right away and it will run bad. but, what if there is still some def in the bottom of the tank and that just keeps coming into the separator, hopefully not beyond?
sorry "is hpfp high pressure fuel pump?" yes
Your instincts were right on target to pull the lift pump fuse. Well what's done is done at this point.
I would just keep draining the separator until you stop getting the water in fuel warning then change out the filters once it settles down. I think I would also dump in some quality fuel conditioner just for added insurance asap.
I use Opti-lube XPD. Ultra low sulfur diesel fuel suffers from low lubricity and I use it to keep the HPFP happy. GM just advised in a supplement (I can't seem to find the link for it) for the 2021's an additive should be used if you're not using top tier fuel stations, good luck trying finding that. XPD is a good all around additive.
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Power Service Diesel Kleen is another popular brand.
Power Service Diesel Kleen is another popular brand.
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