This has NOTHING to do with Porsches...

One of my close friends (3 decades customer/friend who does my Website) screwed up yesterday and put 12 gallons of DEF fluid on top of 10 gallons of diesel in his 2021 Chevrolet Duramax 3/4 ton truck...

He showed extreme foresight in calling me BEFORE he tried to start it again.

I said NO and we had it towed in on a flatbed wrecker.

I'm going to be able to save it inexpensively, but I started a conversation with a long-term parts guy at the Chevrolet dealer that startled me enough to say "Wow, maybe I should post this."

Had Len started it, it would most likely need an ENTIRE fuel system. 10K...

Had he run it down the road it would need the above AND a new engine!!!!!! 30K more!

He called Chevrolet Service first as I am "On Vacation" and my shop is closed to new work till February. He changed the website to reflect this so he did not think I would want to play with his screw-up.
The dealer was ESTATIC to get the truck in!
This type of damage is often covered under the comprehensive portion of the vehicle's insurance.
I believe most dealers would find "needs entire fuel system" with no damage and the owner would have to pay a deducible and be without truck for XX days...

We're going to drain/clean tank and maybe replace the in-tank "sending unit" which I believe is a low-pressure transfer pump. It will get a new fuel filter now and another 2-3 tanks of fuel in the future. Total cost should be less than $300 but I get to deal with 25 gallons of SLIME, the shop will stink for 2 days, and I'm having to come off of vacation to work on BIG ASSED domestic truck which I detest!

Len is "family" and I'm screwed...

Moral of this story: Be insanely careful with adding DEF to your diesel.
They made the DEF fill hole and nozzle SMALLER so you couldn't put diesel into the DEF tank.
It's looking like the reverse might actually be worse...

How could that happen, are the fillers close to each other?

The DEF fill port is 3" away from the fuel fill port...

The DEF port is 1/2 the diameter of the fuel port.

I purpose bought a used Cummins that was pre DEF to tow my 914 to avoid this kinda crap

I was going to make a joke about it being more like pee. I have an 85 ford with the IH 6.9 L diesel. I had heard about some fluid they had to add now but didn’t know what it was called. I had to look up DEF and was really surprised what it was. Synthetic piss in water. Love to know whose idea that was. Thank goodness you were able to save it

Whats a DEF ? thanks.

DEF is 33% urea (the base of urine) and 67% water.

It is injected into the exhaust system pre DPF (diesel particulate filter) to break down the diesel particulates so that they will "burn" into ash.

This ash is RETAINED in the DPH until it is full at which point the DPF should be replaced.

Lots of places clean this ash from DPF (for a fee) making them somewhat re-usable.

DPFs can cost up to 5K!!!!!

Diesels stopped visibly smoking in 2007 because of an ENTIRE slew of emission devices that were required by law...

They got EGRs at the same time and the EGRs required cooling via a heat exchanger that is plumbed into the vehicles cooling system.

They went "bat-shit" crazy on the level of particulates they would accept.

Made diesels substantially more expensive to purchase and maintain.

Had another bad aspect regarding all forms of aftermarket tuning...

Those STUPID BITCHES who made a modern diesel "roll smoke" pissed the EPA off so badly they are far more likely to come visit your "Tuning shop" to see if you, too are breaking the law.

When they start their investigation, you are shut down and no-longer allowed to enter your shop.

The investigation always takes some time.

6 weeks is a fast one.

6 months is more common.

Cobb tuning (Subie guys) went through one of these.

I have been offered multiple tuning opportunities. Managment or ownership.

One of my earliest students runs Alamo Autosports.

I intentionally chose not to do this for other people's street cars for exactly this reason.

I'll stick with my automotive AC business as all I have to do to be legal is not release refrigerants...

Actually, I'm wrong on why DEF is used and what it's trying to achieve...
Can't say I've ever looked it up.

It's injected into the exhaust pre catalytic converter to reduce the level of oxides of nitrogen.

The EGR systems were also for this.

I've noticed some brands use it and some brands don't.

I'll look more closely at Len's truck to see how complex the EGR system is.

DEF is used to combat NOX, it is not used to burn the particulates into ash.

Some diesels actually inject diesel directly into the exhaust during "re-gen" which is specifically targeted for the particulate/DPF issue.
"Re-gen" regenerates the DPF by actual fire in the DPF.

I'm NOT a diesel truck mechanic, I despise these things...

On our P/U truck the DEF tank will hold approx 5 gal of the fluid; a reminder will appear on the pop-up display when you're low & the remaining miles left until empty. Owners manual* is your friend, as the dealer explained -0- about DEF when we took delivery on the truck. Avail for good prices at Costco in 2.5 gallon jugs,
Dealer/ Steeler prices about twice as much $.
* Owners manual suggests not to urinate into the DEF tank

Other things that should be obvious . . .

Don’t put gasoline into a diesel tank

Don’t put diesel into a gasoline tank



Amazing that he had the foresight to call and to and the personal integrity to fess up to what happened before it cost him serious money. Now that is a good friend to have!!

Likewise - he’s awfully lucky to have you as a friend that will work on it for him. I hate the smell of diesel and hate working with the stuff . Get it on your hands, clothes, etc., the smell never seems to go away. I hate that the fuel pump areas always look like a Valdez spill occured there since the stuff doesn’t just evaporate. Lord help you if you step in a fresh spill and then get back in your vehicle; getting it on the floor mats. Stinks up the cabin in no time.

Unfortunately I have a diesel . . . It’s sort of an experiment despite how much I hate the shortcomings of that fuel.

I rented a diesel Hyundai in England and the first 3 days I was really impressed by the milage I was getting. It was then that I realized I had been watching the DEF gauge. I'd never heard of it before that.

Another interesting issue that popped up because of this was the fact that you cannot easily move the shift lever from Park until the engine is actually running.

As this truck was dead-lined for engine start it required "bumping or bouncing" the truck onto the flatbed.
This was the first time I've seen this procedure and it really worked quite well.
The wrecker driver was able to place the truck at the proper depth centered on my lift.



The driver also had access to a paid subscription showing drivers how to get vehicles out of park and other needed techniques to tow vehicles.
His stuff didn't have any data about a 2-year-old truck...

I sometimes have issues with the latest model cars in regard to these things.

Getting the ignition fully ON without starting the engine. Smart keys are not real smart!

Getting the electronic parking brake to release without engine on and not in park.

Getting the transmission out of park not running.

These simple tasks have become far more difficult recently with the complete automation of our vehicles. It's a move BACKWARDS in my book.

I'll figure out how to release the shift linkage, advise my friend of the procedure.


Having a vehicle that you cannot easily make into a roller is a deficiency that might become a serious problem depending on situation.


Have a modern vehicle?

My advice is to figure out how to clear this hurdle on your car before it is a requirement.

In 1985 I learned to love it. I could load two quads and riding stuff in the bed and a fully loaded down 33’ pull behind travel trailer from Los Angeles to Pismo beach at the same speed up hill and down and it never got hot and it never got tired. It’s still around…

Diesel also has some benefits. I believe it has a higher energy content than gasoline. On diesel engines, the power output is almost completely controlled by the amount of fuel going in, so there is no throttle to get in the way of your intake air. It also burns down to a very very lean mixture when low power levels are required. These all contribute to it being noticeably more efficient as a motor fuel than gasoline.

In the old days, before ultra-low sulfur diesel was the standard, it also required less refining than gasoline. So it was cheaper to purchase, as well as using less. Emissions were rather worse in those days, of course...

--DD

Many yrs ago i had a Diesel VW fastback. One evening I was running VERY low on fuel & some way from home. Only gas station around didn't have diesel so i put 1 gal of gas in and shook the car a bit to try to blend the tank. Got home without any issues. It seemed to run fine. I was lucky.

Barefoot

This does have to do with porsches in a way. I had a diesel cayenne for a long time.

I am always so paranoid when taking my diesel truck to the station for fuel. Convinced I'll someday put gas in it. I hate loaning it to people which doesn't happen often, but occasionally. I'll usually say, please don't fill it with fuel, just let me do it.

Many years ago I was an exec at Gettty Images and had a team in London. The guy running that team was new in the job and from the US. I took one of many trips over there to meet up with him shortly after he got settled. He picked me and another co worker up at the airport. He dropped us at the hotel to drop our luggage off and we were set to go see some sights outside of London.

He had a company provided Mercedes wagon. When we got back to the car it wouldn't start. First thing I said was, are you sure it isn't just out of fuel. Yeah, I just filled it up on my way to the airport. I ask, is it gas or diesel? I knew from the look on his face he was clueless being from the US. Huh, why would it be diesel? I said, a lot of cars in Europe are diesel. Sure enough, looked inside the filler cap, it was diesel. That was an expensive lesson for him.

He didn’t even know after driving it.

Not car smart at all

And I also love my diesel Cayenne! She's a beast on the road pulling my trailers.

25 gallons in, fuel tank out, transfer pump and sending unit replacement.

Has a roll over valve but we got by it with a piece of 5/16 fuel hose.

Old fashion syphoned 23.5 gallons. Took 45 minutes.

DEF is heavier than diesel and at one point got 5 gallons of clean DEF out.

DEF IS fertilizer, really it is...

DEF and diesel separate quickly.

My buddy Cory is going to burn the diesel in his shop heater and I'm going to poor the DEF on bare patches of grass here.

100% recycling this crap...

Easiest fuel tank pull in 2 decades. NO evap lines at all.

Also haven't spilt any yet so the stench is at a minimum...

DEF made it to the external fuel filter. Going further upstream to investigate more.

Still looks like less than $300 in parts.

Looking savable.

Gas tank has the NICEST inner lining I've seen yet. Light gray, Super easy to see any debris. Entire inside of tank visible and accessible through FP mount hole.

Power to transfer pump is exotic through a fuel pump control module with enough wiring to make me think I'm looking at PWM stuff. Didn't look easy to trick the pump into functioning. Thankfully the syphon worked GREAT!

More later

Rick

Just guessing, but I bet the dealer can use the brand proprietary computer system to control these. The rest of us are SOL.

Target Down...
Great White Whale runs again.
Total cost:
Fuel tank sending unit. 171
2 GM fuel filters 100
Sales tax 19
25 gallons Diesel 85

Total 375

Never letting my friend off the "hook" for putting DEF in his gas tank...
Priceless!

last year i was with my good friend, my structural engineer consultant for the last 35 years.

we blew his VW Toe-rag up. cracked the head.

about a week or two before it happened he got a tank of crap diesel from some back woods servo when his tank was nearly empty.

he paid the price.

it got progressively worse over a fortnight. rough idle ........stuck injector?

the VW dealer could not book it in and we had to do a site visit up country.

we did not get to the site visit.

Toe rag expired in a cloud of white smoke with an exhaust dripping water.

having inspected the engine visually i would never get one.
heat exchangers and coolant loops everywhere.
beyond sanity.

it hydrauliced on over fueling. and it cracked one of the heads. V6 d.



junk. and i'm not just canning VW.
i've seen a big citroen C6 that did the same thing to its d engine.
write off. and thats a gorgeous car to write off too. unlike a toe-rag.

There is a 97 Suburban with 28k original miles on BAT today. If I was prepared, I'd ditch my 2017 diesel truck and bid on it. I've already had the low pressure turbo replaced under warranty. A few other small things as well. It just turned over 50k miles. I need a tow rig for a 26 foot travel trailer but I'll never buy another newer diesel truck. Given all of the electronics that go wrong in new vehicles, it would be nice to have something from the 90s. The Suburban would tow it just fine with some fun mods. It's the same color as the 99 I had years ago.

Have a 2015 Q5 TDI. I get 35mpg easily o the freeway. Tows like a mule on crack.
I still winder how he got 11gal of DEF in. I buy them in 1 gal containers.
1gal lasts me 5 months.

The only real problem I've encountered is B20. Chevron had been known for higher fuel quality. I require B2. They swapped over and I ran a full tank in setting off the check engine light.
Now I'm replacing sensors.

What a pain

We have DEF pumps here (WITH the normal diesel pumps right next to it).
Both dispensaries next to each other. Both fill ports next to each other.
Little bit of 'not focused on what's happening" and a trip to the rest room created this issue.
Being smart enough to not "try it" before calling me saved him thousands!

He WON"T forget again!