Unleaded Fuel In Diesel

[Daffy]

Petrol isn't a lubricant like diesel and washes the protective film away from expensive parts that are exposed to high load and pressure, it also contains a lot of water (when compared with diesel), best thing is to get it out quickly and fill it with the best quality fuel you can find (eg Shell Advance diesel or another high spec fuel as in Europe these tend to be more like the traditional fuel that we used to buy rather than the rubbish that is normal diesel)

If you can hand prime the system rather than crank it to get it going.

The issue with the water is it doesn't take long to damage components with very high tolerances so get it out quickly and don't worry too much.

 

[Docs]

Hi , I have just filled up unleaded petrol into my diesel 2018 caravelle, estimate 6 ltr diesel before filling - How stupid could I be? - drove about 6 klms .
Caravelle taken on tray truck to RACV centre to fix. Now I am sweating on damage done and repair costs

 

[ollie_d_c]

Hi, dare I ask what the damage was? I did something similar but fortunately realised straight away.

 

[Fluff34567]

My business partner's wife has twice filled up a petrol car with diesel and it seems this is much much worse than the other way round

Did she use a funnel?

 

[Docs]

Hi, dare I ask what the damage was? I did something similar but fortunately realised straight away.

RACV service center said petrol in a diesel fuel tank happens often. When told that I had driven about 6 km they would not guarantee their work. However they drained the fuel system and the car to date has not had any performance problems (approx 4000 km and I still worry)
Cheers, Doc

 

[Ayjay]

I hope it all works out for you. A few years ago, my wife filled her then three week old Honda Civic (and our first diesel car) with petrol and drove it about about 20 miles home without realising the mistake. When it wouldn't start the next morning, we called the AA and while waiting for them to arrive I had a poke round the engine and also took off the filler cap and immediately smelt petrol. I didn't say anything to her about it (as she would have denied it and probably started a row!) but pointed the AA guy in that direction when he arrived and he immediately concurred. The outcome was a tow to the Honda dealer and about £4K worth of repairs. She's never done it again.

I can also vaguely recall seeing a motoring programme on TV a long time ago when they intentionally misfueled a number of cars to see what the impact was. IIRC, the consensus was that if you filled a petrol car with diesel, it ran a bit rough and maybe stopped altogether but there was no long term damage once the diesel had been drained and replaced with petrol. Diesel cars on the other hand didn't like petrol at all but the amount of damage and therefore remedial work (and associated costs) really depended on how old the car was - a (then) modern diesel being the worst case scenario.

 

[Skyliner33]

I thought the filler nozzles of petrol and diesel pumps were different sizes, id one was bigger so wont fit in the other so you cant misfill one way?

 

[Spaghetti]

I thought the filler nozzles of petrol and diesel pumps were different sizes, id one was bigger so wont fit in the other so you cant misfill one way?

I believe diesel is wider but I’ve known people to just ram it into an unleaded filler neck.

 

[T6Andy]

I've done it mate.. think it was 30£ I put in.. didnt want VWassist to get involved so filled the remainder with D and cracked on..
my fault.. my cost!.

I was on empty last night out about 12litres of unleaded in and realised. Fill the remainder of tank with Diesel and travelled the 6 miles home. Seemed to be ok. I have a 2016 shuttle 204dsg. I’m now wondering should i call out a misfuel company to drain it or do as I’ve read online and add some 2 Stroke Jaso FB mineral oil to the tank to help lubricate, where the petrol might wear. Anyone use 2 stroke mineral I this example?

Latter,been ok since. Learnt lesson tho..lol. nothing reported on services or health checks and Dale(Listers) was aware of it.

@Fish i put in circa 12 litres of unleaded into empty tank about £19, realised on forecourt before starting engine and immediately filled tank to brim circa £80+ with diesel and then drove 6miles home with no audible or visible signs of issues. I’m hoping the dilution was such that I will be ok. But have read putting 2 stroke mineral oil Jaso FB grade in at 200:1 ratio would help with lubrication that the petrol could strip out of the diesel. I’m unsure to just leave with current dilution and top up for next few weeks with premium grade diesel and hope that does the trick.

Is yours still ok, no other after effects?

 

[DXX]

I was on empty last night out about 12litres of unleaded in and realised. Fill the remainder of tank with Diesel and travelled the 6 miles home. Seemed to be ok. I have a 2016 shuttle 204dsg. I’m now wondering should i call out a misfuel company to drain it or do as I’ve read online and add some 2 Stroke Jaso FB mineral oil to the tank to help lubricate, where the petrol might wear. Anyone use 2 stroke mineral I this example?

Not good, it’s already done. Yes drain the fuel.
You can get away with diesel in a petrol engine but never petrol in a diesel. The HPFP and injectors rely on diesel for lubrication.

 

[T6Andy]

Not good, it’s already done. Yes drain the fuel.
You can get away with diesel in a petrol engine but never petrol in a diesel. The HPFP and injectors rely on diesel for lubrication.

If the mix in the tank is 85% diesel and 15% petrol I’m thinking I might just get away with it. Especially if I either top up the tank with about 400ml of 2 stroke mineral oil Jaso FB grade or keep topping up with premium diesel daily, which will dilute the unleaded mix daily. @Fish further up the thread seems to have managed through the same scenario with even more unleaded in his tank.

 

[DXX]

If the mix in the tank is 85% diesel and 15% petrol I’m thinking I might just get away with it. Especially if I either top up the tank with about 400ml of 2 stroke mineral oil Jaso FB grade or keep topping up with premium diesel daily, which will dilute the unleaded mix daily. @Fish further up the thread seems to have managed through the same scenario with even more unleaded in his tank.

When you add injector cleaner (150mL of alcohol) to a full tank of fuel it states not to add more than one bottle, reason being that it is a solvent. You’ve added 15000 mL of something almost as solvent.

Aside from fuel system lubrication there is the issue of detonation (knocking) and potential engine damage.

 

[T6Andy]

When you add injector cleaner (150mL of alcohol) to a full tank of fuel it states not to add more than one bottle, reason being that it is a solvent. You’ve added 15000 mL of something almost as solvent.

Aside from fuel system lubrication there is the issue of detonation (knocking) and potential engine damage.

I get that piece around it over cleaning the engine and acting as a solvent, but that’s why some diesel experts say to add 2 stroke mineral oil of Jaso FB grade to the fuel tank too, as that adds an extra lubricating property to counter act the petrol acting as a solvent.

With me having not driven any miles or in fact switching the engine on with just petrol in the tank, and then only driving 6 miles with the mixed fuel, my thinking is that if I now syphon off say another 20L of the current mixed fuel tank and add 400ml of the 2 stroke mineral oil plus then top up with a fresh 20L or premium diesel then I should be ok.

Especially if @Fish managed to get away with his £30 of unleaded being added to his tank.

 

[roadtripper]

If you're going to take 20l of the contaminated diesel out I'm curious why you don't just take it all out?

I get that fuel is expensive right now, but so are engine rebuilds.

 

[T6Andy]

If you're going to take 20l of the contaminated diesel out I'm curious why you don't just take it all out?

I get that fuel is expensive right now, but so are engine rebuilds.

I’ve ordered a syphon but I’m not sure where I’d put 80l of mixed fuel tbh. How I could dispose of it safely. I’ve a tree stump that needs to stop sprouting so had thought 20l could be used there to kill birds. I think 80L would see Greenpeace and Swampy at my door!!

 

[DXX]

I’ve ordered a syphon but I’m not sure where I’d put 80l of mixed fuel tbh. How I could dispose of it safely. I’ve a tree stump that needs to stop sprouting so had thought 20l could be used there to kill birds. I think 80L would see Greenpeace and Swampy at my door!!

Do you know anybody with an oil fired boiler?

 

[T6Andy]

Do you know anybody with an oil fired boiler?

No unfortunately.

 

[Dellmassive]

I’ve ordered a syphon but I’m not sure where I’d put 80l of mixed fuel tbh. How I could dispose of it safely. I’ve a tree stump that needs to stop sprouting so had thought 20l could be used there to kill birds. I think 80L would see Greenpeace and Swampy at my door!!

the diesel tank has an anti syphon trap.

@DannyPearson just come up against this when the derv tank had a load of adblue dumped in it.

he tried pumping out. .



and he tried breaking the fuel line and looking to drive the lift pump. . .




+++

The OEM guidance is to drop the tank and flush,

there are mobile companies that will do it roadside,

the AA and RAC also provide this service, ( might be worth a call?)

+++

more info here:

T6 - Mis Fuel Procedure

~manual section for dealing with a mis-fueling situation.

www.t6forum.com

 

[T6Andy]

Ah, so a hand syphon won’t work then?

 

[Dellmassive]

doubt it ( though i haven't tried myself)

but an sure the T6 has a anti syphon flap to stop people nicking your diesel.

most modern tanks have this feature.

stealing fuel was a big thing in years gone by apparently.