Unleaded...I can’t believe it happened!

[Brid]

Don’t ask me how, but 16L of diesel got topped up with 40L unleaded petrol in my Puma common rail diesel.

I drove about 8km in it, when I noticed a slight hesitation (which I thought was a repetition of a throttle response issue I had a few months ago). So at the next set of lights I stopped to turn it off and re-boot the computer, which had cleared the earlier problem. This time, however, it didn’t restart.

A passing Defender owner quickly offered to tow me around the corner. Many thanks to Ben for getting me out of the busy Friday arvo peak hour traffic!

At this point, I was thinking it must have been water in the diesel, but after pulling the fuel filter off, it was pretty obvious it was petrol!! So drained the tank, put 20L diesel in, pulled the fuel return line off the filter, and blew air into the tank to purge everything out of the fuel system. I wasn’t game to crack off the injector lines because of the high rail pressure.

I started it...and a bad detonation rattle, so turned it off again and purged a bit more. Restarted, and detonated again. Third time and it purred like a kitten…sweet sound!! Probably just the bit of unleaded in the injectors that I wasn't game to crack open, without some expert advice at hand.

I’ve just returned from my regular Central Queensland trip in it, putting another 200L diesel through it, and there appears to be no indication of damage. I guess I’m pretty lucky that I switched it off, when I thought the ECU needed re-booting!! But I can’t understand how it could drive 8km on 70% petrol, before any sign of anything wrong!!

[JamesB71]

Sounds like you were lucky!

[spudboy]

Sounds like the PUMA engines are tougher than we think!

Hope there's no long term issues, and it keeps going happily.

[the_preacher1973]

But I can’t understand how it could drive 8km on 70% petrol, before any sign of anything wrong!!

It didn't. It drove 8km on the fuel in the lines, the filter and the diesel in the bottom of the tank. Diesel is heavier than petrol.

[VladTepes]

When you say you drained the tank - where, how, into what ?

[nedflanders]

Sorry to jump in and I'll probably get flamed for only talking from experience but as an RAC patrol in the UK I saw a lot of misfuels, a few years ago when diesels where just getting popular the dealers used to insist all lines, filters, pumps, injectors where changed as irreparable damage would have occurred. This didn't last long before people just started draining the systems and changing the filters with no apparent damage. In fact the RAC in the UK have specific Fuel patrols to carry out exactly this and is endorsed by most dealers ad hire car firms. What I did find is that the Petrol and Diesel didn't really mix and if the majority of fuel in your tank was Diesel and you'd only topped up with petrol it could run for quite awhile, I had an Audi drive 60miles with no problems, until she turned it off and it wouldn't restart, cracked the injectors and it was just petrol coming out. What I'm trying to say is the myth is still pretty much alive in Australia that you will destroy a common rail by misfueling, it's what the dealers and garages want you to believe as it's a huge money earner.
Now before someone jumps up and down saying I'm talking bollox I'm happy to have an adult debate without getting personal :)

[goingbush]

Think Ned is on the Money

I filled a Telstra Ford Ranger with Unleaded, drove similar distance,
about 5km (but downhill) the motor would only idle roughly then died.

I got it RACV towed home, The RACV man told me the Fuel system would need replacing, It was Friday arvo & I needed to go home & not to a repair centre so he relented called me an idiot and towed me home.

At Home I disconnected the fuel line from the injector pump & used a facet pump to fill 4 jerry cans, didnt flush any lines or anything, put one Jerry of Diesel into the tank & it started pretty much away & no problems since whatsoever.

[Phil HH]

The missus did something similar with our old turbo Pajero some time ago. Drove about 8 km and then there was a loud backfire and a big cloud of black smoke out the exhaust. The fuel tank was drained into drums, and the filters changed. No apparent damage, and it ran just fine for ages. Disappointingly the mower didn't take to the diesel/petrol mix, and I still have some of it in a drum somewhere.

[nedflanders]

Think Ned is on the Money

I filled a Telstra Ford Ranger with Unleaded, drove similar distance,
about 5km (but downhill) the motor would only idle roughly then died.

I got it RACV towed home, The RACV man told me the Fuel system would need replacing, It was Friday arvo & I needed to go home & not to a repair centre so he relented called me an idiot and towed me home.

At Home I disconnected the fuel line from the injector pump & used a facet pump to fill 4 jerry cans, didnt flush any lines or anything, put one Jerry of Diesel into the tank & it started pretty much away & no problems since whatsoever.

What you'll find (and I did a short stint in an RAC garage in Australia) is Patrols are encouraged to push for the car to be taken to a garage (preferably an RAC one) for a new system. I saw a RRS while in this garage and I think the quote was upwards of $7K, it got me thinking about setting up a business purely for misfuels in Perth but i think I need to wait until Diesels become more popular ;) I'm sure the RRS driver would have preferred to pay $400 for a drain and flush than $7k for a full system as most insurance doesn't cover it (read the small print :( )

[isuzurover]

About 6 months ago I posted some university research on ethanol/diesel blends. Up to 85% ethanol was tried in a diesel in one study...

Diesels are much less susceptible to detonation damage than petrols. Short term misfuelling with petrol won't be long enough to cause the pump or injectors to wear due to low lubricity. The only other concern is that the higher aromatic content of the petrol will affect seals and/or lift pump diaphragms.

In short - should not have done any significant damage.

[CharlesTeton]

Thanks all for the heads up...

[Didge]

My son put 20 litres of unleaded in and that was about all the fuel it had; ran like a dog but after changing filters, cracking the injectors and all joints, cranked the engine to expel the petrol, topped it up with diesel and off we went - no problems - but it is a 300TDi and apparently they'll run on road bitumen :D

[dromader driver]

If you know what you put in vis how much petrol and diesel donate it to your bushfire brigade. The will use it for driptorch fuel. :cool:

[Didge]

Good idea, what about old, old petrol (1 - 2 years), like from outboard motors? they interested in that?

[Bushie]

Sorry to disappoint Didge - but locally we won't be interested in any of it.


Martyn

[NT5224]

Thanks everybody for sharing these experiences and insights - I've found it a really useful thread.


Alan

[spudfan]

Suppose this happened in the middle of nowhere, i.e. a couple of your jerry cans had petrol instead of diesel in them, could you throw in a litre of 2 stroke to help with the lubricity of the mix. Could you drive on this mixture until you could find somewhere to top up with diesel?

[OneGoat]

Last year when we purchased the TD5 D2a, the at home "Boss" put close to 30 litres of petrol in before she realised. Before she filled up the tank had less than a quarter of diesel in it, fortunatly she rang from the petrol station and I told her to get some oil and put 2 litres in then fill the tank to the brim with diesel.
She drove approx 45ks to get home with no problems noted. I then drained about half the tank and topped up with more diesel and conditioner and over the next few re fills used up the rest of the mix.
Then changed the filter figuring the petrol might have dislodged some gunk.

Have done about 35,000 ks since without hickup. :angel:

[BilboBoggles]

...

[goingbush]

Suppose this happened in the middle of nowhere, i.e. a couple of your jerry cans had petrol instead of diesel in them, could you throw in a litre of 2 stroke to help with the lubricity of the mix. Could you drive on this mixture until you could find somewhere to top up with diesel?

probably not, but you could happily run on kerosine with a bit of 2 stroke thrown in. (Not that you would have a jerry of kero with you )

[isuzurover]

Suppose this happened in the middle of nowhere, i.e. a couple of your jerry cans had petrol instead of diesel in them, could you throw in a litre of 2 stroke to help with the lubricity of the mix. Could you drive on this mixture until you could find somewhere to top up with diesel?

Most diesel engines will run on fuel that is up to 30-50% petrol. The 85% I mentioned the engine was barely running and you would not expect enough power to be produced to drive (maybe in low range...).

By adding 2-stroke you could possibly both help the fuel combust and improve lubricity.

Kerosene is usually used as a "worst case lubricity" fuel when testing diesel engines.

There have been a couple of cases where offshore trawlers have used all their fuel in bad weather and resorted to putting their spare lube oil in the fuel tank in order to get back into port. The consensus from the engine suppliers were that no long term harm would be done if it was for short periods.

However this has all been about the mechanical components. The electronics may shut the engine down or go into limp mode if it detects operation outside of normal parameters.

[landoman]

I have a 2016 defender . It has a 70 litre tank
On weekend driving from Melbourne to Sydney I stopped for fuel at Wallan on the Hume highway . Got distracted and dumped some unleaded in before I realised my mistake

On refueling
tank had 25.02 litres of Diesal in it
I put in 22.70 litres of unleaded before realising my stupidity
I then topped up with 22.28 litres of Diesal to fill tank to 70 litres

Garage attendant told me Diesal is heavier than petrol so as long as I keep topped up
it should be ok as the unleaded will stay on the top and the Diesal will get drawn from the bottom

Car drove fine no backfiring or loss of power and engine sounded as normal.

refueled with Diesal as follows

24.17 litres at Glenrowan
17.7 litres at Albury ( also added some Diesal conditioner ((DC))
25.00 litres at Gundagai ...with DC ...small squirt
15.60 litres at Yass with DC ...small squirt
14 litres at Goulburn with Dc ...small squirt


I arrived in Sydney with 3/4 of a tank and the car seems to be running running fine

so some questions ......

1) Do I still have 22.70 litres of unleaded floating on top of my Diesal .....or ( as I suspect ) has it completely mixed in with the Diesal ......and now diluted due to the many top ups

2) should I still drain the tank or should I just keep topping up with Diesal to
completely dilute away the unleaded

3) I have read above that I should at least change the fuel filter


any and all advice suggestions appreciated .

[goingbush]

I have a 2016 defender . It has a 70 litre tank
On weekend driving from Melbourne to Sydney I stopped for fuel at Wallan on the Hume highway . Got distracted and dumped some unleaded in before I realised my mistake

On refueling
tank had 25.02 litres of Diesal in it
I put in 22.70 litres of unleaded before realising my stupidity
I then topped up with 22.28 litres of Diesal to fill tank to 70 litres

Garage attendant told me Diesal is heavier than petrol so as long as I keep topped up
it should be ok as the unleaded will stay on the top and the Diesal will get drawn from the bottom

Car drove fine no backfiring or loss of power and engine sounded as normal.

refueled with Diesal as follows

24.17 litres at Glenrowan
17.7 litres at Albury ( also added some Diesal conditioner ((DC))
25.00 litres at Gundagai ...with DC ...small squirt
15.60 litres at Yass with DC ...small squirt
14 litres at Goulburn with Dc ...small squirt


I arrived in Sydney with 3/4 of a tank and the car seems to be running running fine

so some questions ......

1) Do I still have 22.70 litres of unleaded floating on top of my Diesal .....or ( as I suspect ) has it completely mixed in with the Diesal ......and now diluted due to the many top ups

2) should I still drain the tank or should I just keep topping up with Diesal to
completely dilute away the unleaded

3) I have read above that I should at least change the fuel filter


any and all advice suggestions appreciated .

It will be perfectly OK, the unleaded will have well and truly mixed with the diesel in the first hour , prob in the first 5 mins, no need at all to keep it topped up. just keep driving as normal.

[Blknight.aus]

Suppose this happened in the middle of nowhere, i.e. a couple of your jerry cans had petrol instead of diesel in them, could you throw in a litre of 2 stroke to help with the lubricity of the mix. Could you drive on this mixture until you could find somewhere to top up with diesel?

yes but it depends on the mix, if you can get it started dont stop it and dont ask too much power you'll be ok, petrol burns hotter and faster than diesel so you will be getting detonation which if driven hard will damage pistons, extended driving will up the combustion temps and then the lack of lubricity might be a problem for the injectors, High pressure pump, pressure regulator or the suction control valve.


I have a 2016 defender . It has a 70 litre tank
On weekend driving from Melbourne to Sydney I stopped for fuel at Wallan on the Hume highway . Got distracted and dumped some unleaded in before I realised my mistake

On refueling
tank had 25.02 litres of Diesal in it
I put in 22.70 litres of unleaded before realising my stupidity
I then topped up with 22.28 litres of Diesal to fill tank to 70 litres

Garage attendant told me Diesal is heavier than petrol so as long as I keep topped up
it should be ok as the unleaded will stay on the top and the Diesal will get drawn from the bottom

Car drove fine no backfiring or loss of power and engine sounded as normal.

refueled with Diesal as follows

24.17 litres at Glenrowan
17.7 litres at Albury ( also added some Diesal conditioner ((DC))
25.00 litres at Gundagai ...with DC ...small squirt
15.60 litres at Yass with DC ...small squirt
14 litres at Goulburn with Dc ...small squirt


I arrived in Sydney with 3/4 of a tank and the car seems to be running running fine

so some questions ......

1) Do I still have 22.70 litres of unleaded floating on top of my Diesal .....or ( as I suspect ) has it completely mixed in with the Diesal ......and now diluted due to the many top ups

2) should I still drain the tank or should I just keep topping up with Diesal to
completely dilute away the unleaded

3) I have read above that I should at least change the fuel filter


any and all advice suggestions appreciated .

as mentioned earlier the fuel will be mixed thoroughly by now.

as diesels generally have a full flow system with excess returning to the tank at the top, the vehicle will be agitating the fuel from the driving motions theres no way the unleaded will just "sit" on top of the diesel. If you left it to sit long enough and it was warm enough it might fraction out a little.

My guess is that by now youd be at about 5%

using rough and round numbers your initial petrol contamination of the diesel was 33% 22l and 44l of diesel. 66l total capacity. ( I left out the extra bits of diesel, it makes the numbers worse.)

you used 24 of that.. and added 24l of diesel, Lets say you used 21l and added 21l of diesel (works against you the numbers are easier) and had perfect mixing you used 7l of the petrol and 14l of the diesel. so now you have 15l of petrol in 66l of fuel, something like 22% mix

and again 17L you used 3.75l of petrol and the rest diesel, you now have 11.25l of petrol in the tank the rest diesel, 17% mix.


of the next fill of 25l 4.25l would have been petrol burnt so you now have 7l of petrol in the diesel, 10.6% mix

15l of fuel used at 10% is 1.5l leaving you with 5.5l of petrol in the 66l tank thats... 8.3%

14l used at 8.3 is 1.1L (its 1.16 but Im working the numbers against you) so you now have 4.4l in a 66l tank which is 6.6% and give or take a hand full of liters and rounding it means you're under 5% and if you're really worried about it, go run the tank close to dry under light loads and then top it up..

next time you do something like that, feel free to syphon the fuel for me and I'll run it through my donk, Its not going to care about those kind of numbers if I stick it in the long range tank...

[LRJim]

Next time just keep filling it up with petrol then ad a few litres of engine oil, give the car a shake and keep on going [emoji16]🤣🤣

[landoman]

Thanks to all for the advice, much obliged
As reccommended I’ll run out the 3/4 tank and then completely refill with fresh Diesal
Had read somewhere that adding some 2 stroke oil to the contaminated Diesal could be helpful
for lubrication
SHould I do this or not and if so , how much 2 stroke oil should I add to 3/4 of a 70 litre tank?

[Bearman]

I wouldn't bother adding any 2 stroke oil. The diluted fuel will be fine to run as it is.