DEF (diesel exhaust fluid) in my fuel tank - we're stranded

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H5-Phil

Well-known member
Joined
May 24, 2017
Posts
140
Location
Penryn, CA. (foothills of the Sierra)
I'm hoping this post might help others if they find themselves in our situation.  I'm about 4-years into owning my first diesel truck.  My worries about grabbing a gas pump out of habit, have greatly diminished.  My fears of putting DEF in my fuel tank had likewise diminished - I was feeling good that I had avoided the rookie mistakes of a new diesel owner.  I should have never let my guard down!

Last Friday, I planned to fuel and add DEF (in that order) to my truck since I was getting low on both.  My plans changed when I noticed an auto parts store on the way to get fuel.  With my brain disengaged, I grabbed a box of DEF and proceeded to remove my diesel cap.  I added all 2.5 gallons to my diesel tank!!  Yep, only when I went to put my 'DEF' cap back on did I suddenly realize my blunder.

Here's what I hope might help others that find themselves in this situation.  Luckily, I didn't turn my key on or try to start my truck.  This was critical to keeping the DEF isolated to the fuel tank.  Most importantly, an expert diesel mechanic happened to be in the auto parts store.  He immediately crawled under my truck and drained my fuel filter, he also disabled my fuel pump by pulling the fuse.  He explained that simply turning the key could have sent contaminated fuel to my fuel system!  He said starting it would have been disastrous.

With the fuel pump disabled, I was able to turn the ignition on, allowing me to put my truck in neutral and to straighten the wheels for loading on the flatbed tow truck.  That mechanic saved me thousands of dollars and charged me nothing!!
 
The total estimate for repair, since the DEF is isolated to the fuel tank, is only $900.00!!  Had I turned the key to the on position, or worse yet tried to start my truck, this estimate would be thousands more.

As far a being stranded, we're staying at a coastal RV park and they can extend our stay until the truck is ready :).  So, we're stranded in a nice place.
 

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Glad you came out of it not too bad - as compared to starting it etc.

I don't used DEF in my MH - so I'm curious as to -

Are the diesel and DEF fill points close to each other?
Same fuel door used to access both caps?


Was it a case of just dropping the fuel tank and draining out the fuel and DEF?
Did it require more cleaning then just dumping out the mixture and then reattaching the tank and filling with just diesel?
Did insurance cover the tow?  OR was that part of the $900?

IF you had an almost full tank of fuel - say ? full - would 2.5 gallons of DEF be diluted enough to run?  OR is any DEF - even a small amount
enough to cause major problems?
I thought I read somewhere that you could could run DEF in the Fuel tank but that it was more expensive so only by accident/mistake
would anyone do that.  Maybe I read it wrong IDK.

Thanks for the report as I'm sure it will help other to pay attention - as anyone can get distracted. 
 
DEF and diesel are side by side, common to the same fuel door.  My understanding is that the Ford dealership is removing the tank for cleaning and replacing the fuel filter - not sure what cleaning method they'll use.  Our AAA insurance covered the towing of our truck.  Our TT was already parked at the RV resort (but our insurance would have covered that too).  According to the diesel expert that helped me, any DEF in the fuel is unacceptable.  I did find a forum where a guy in the same situation called his diesel person and was told it was "diluted enough" to drive the truck - he ended up having to have major work done on the motor costing thousands of dollars.

The first mistake is putting the DEF in, the second, and more costly mistake, is turning that ignition key.  I got VERY lucky.


RedandSilver said:
Glad you came out of it not too bad - as compared to starting it etc.

I don't used DEF in my MH - so I'm curious as to -

Are the diesel and DEF fill points close to each other?
Same fuel door used to access both caps?


Was it a case of just dropping the fuel tank and draining out the fuel and DEF?
Did it require more cleaning then just dumping out the mixture and then reattaching the tank and filling with just diesel?
Did insurance cover the tow?  OR was that part of the $900?

IF you had an almost full tank of fuel - say ? full - would 2.5 gallons of DEF be diluted enough to run?  OR is any DEF - even a small amount
enough to cause major problems?
I thought I read somewhere that you could could run DEF in the Fuel tank but that it was more expensive so only by accident/mistake
would anyone do that.  Maybe I read it wrong IDK.

Thanks for the report as I'm sure it will help other to pay attention - as anyone can get distracted.
 
RedandSilver said:
Was it a case of just dropping the fuel tank and draining out the fuel and DEF?
Did it require more cleaning then just dumping out the mixture and then reattaching the tank and filling with just diesel?
Did insurance cover the tow?  OR was that part of the $900?

IF you had an almost full tank of fuel - say ? full - would 2.5 gallons of DEF be diluted enough to run?  OR is any DEF - even a small amount
enough to cause major problems?
I thought I read somewhere that you could could run DEF in the Fuel tank but that it was more expensive so only by accident/mistake
would anyone do that.  Maybe I read it wrong IDK.

Take a look at this article: https://www.dieselworldmag.com/ford/when-def-is-death/
 
I worked for a truck fleet and one of the drivers pumped in DEF into the fuel. I don't recall how much. Then took off, didn't make it very far till the engine froze. IIRC the truck only had 50k miles on it.

Best think that happened to you was that someone saved you a lot more than $900.
 
The DEF inlet is also under my hood on the truck.
I did almost do a big blunder shortly after I got my truck. I pulled into a SUNOCO station and wanted diesel fuel. There was a pump off to the side so I went up and started pumping. I no more than squeezed the handle when I saw the words racing fuel. This station is 5 miles to a stock car track and they sell racing fuel. I don't think I put in more than a qt. I took the chance and drove it. Everything went OK. I'm sure the fuel just evaporated  after a while.
 
Perspective is so important.  As I'm reading your story and your response it strikes me that you may be actually smiling when you were writing.  Not smiling for the mistake or the loss of $900 bucks, but smiling with happiness for the help the diesel mechanic gave you at no cost to you and you realizing it could have turned out so much worse.

It makes me happy that a stranger went out of his way for no reason other than to be nice to help you in a time when you needed skills that only he had at the time and happy for your attitude.

I have really never even given it a second thought - diesel goes here and DEF there - Now I am going to be so paranoid and I guarantee for the next several years every time I get either I will think of your post.
 
RRR:  We agree wholeheartedly.
ClickHill:  A complete stranger helping to this extent (or at all) while expecting nothing was unexpected and inspiring.  I have his business card so we intend to send Eduardo something nice to show our appreciation...
 
  Good post. My previous Ford had the DEF fill in the same location as fuel. My current Chevy has it under the hood, which I have cursed before because it?s not as handy. I?m changing my thinking on that because of your post. Appreciate it.  ??
 
Well, I got my truck back yesterday from the Ford dealership near us.  The total cost of repair was $967.00.  That's a drop in the bucket compared to what it could have cost had I turned the ignition key!!  I was very impressed with the Ford dealership that did the work, they took it in on a Friday afternoon and I picked it up the following Monday. 

Also, 'docj' shared a link about the perils of adding DEF to your diesel tank.  In that report, it mentions that disconnecting the batteries prevents the fuel pump from being energized when you turn the key, which it does.  However, in my experience, you can't take the rig out of park or turn the wheels with the batteries disconnected (we tried that).  We used my Ford manual/fuse diagram to isolate power to the fuel pump.  This allowed me to turn the key (very nervously) and take the truck out of park.
 
judway said:
What happens if you don't use any DEF?
My engine will go into 'limp-in' mode, I believe. It's all part of the system and required to meet EPA regs.


Edit: Actually, I just remembered.  Once the low DEF warning is triggered I have about 20 starts and then it's tow-truck time.
 
judway said:
What happens if you don't use any DEF?

My trucks computer shuts it down gradually as the DEF gets down low in the tank. It will get to a point where it will not run at all.
 
Sorry about your experience.  I am sure you will not forget.
 
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