[Closed] So, I have this friend who put unleaded in his diesel van...

you might get away with it.

key thing will probably be whether the petrol content stops the fuel pump being lubed properly.

I understand that this should be OK, as long as you keep topping it up regular like. [s]I[/s] Someone I know once put a FULL tank of diesel in [s]my[/s] their diesel Passat and had the great idea of trying o get it home. It just stopped, got towed to the garage and sorted.

FWIW your insurance generallt covers you for such mishaps.

Friends van? No problem, fill his boots (and tank with DERV).

Your van? Ahhhh.... Mebbies a more salutary approach is called for....

I'd refill with derv when more like 3/4 full rather than 1/4.

Not only will it explode, but the pollution coming from it is so toxic that every baby robin within a 100 miles will instantly die.

I did it in a transit connect a few years ago, I think topping it up completely every time the tank is a quarter down would be a better idea,as it is the pump that is starved of lube. In your favour is the fact that it is a big tank. Keep filling it up and you will get off with it.

You only need to pass this on if he is a close mate of course.... 8)

Head somewhere really cold as you now have extreme winter derv.
As above I'd top up at 3/4 full just to keep diluting it. Could get smokey out the back too.

[i]I'd refill with derv when more like 3/4 full rather than 1/4. [/i]

Yeah, that is the plan, 1/4 would be the absolute bare minimum.

[i]baby robin within a 100 miles will instantly die.[/i]

Meh, **** 'em 😉

There is a petrol/derv ratio that is supposed to be fine - I suspect you're over it but I'd go with your plan (top up frequently).
I think the injectors are the other bits that require lubing by the diesel.
[I am not a mechanist so probably talking rubbish but between the wife and I we have done this 3 times 😳
Fixed it by replacing the petrol car with a diesel one]

Meh, **** 'em

What if its a child's face?

So how long should my friend stick to the 'keep topping up at 3/4's full' regime?

[i]What if its a child's face? [/i]

You'll have to take me at my word that I'd never fill a child's face with unleaded.

So how long should my friend stick to the 'keep topping up at 3/4's full' regime?

Sounds like a perfect opportunity for a spreadsheet and some charts plotting the concentrations. You'll still end up with homoeopathic petrol though. My friend put almost a full tank of petrol in his diesel, he was an idiot and charts couldn't help him.

5th gear did a test years ago:

Filled a petrol car with diesel and a diesel car with petrol.

The diesel engine with petrol worked fine, the petrol car didn't.

STOP NOW!

Get the fuel drained.

It's just not worth the potential grief on a modern diesel.

Theres two potential issues - one is the fuel pump being stripped of lube by the petrol, the other (with some engines) is any rubbers and plastics in the fuel line can sometimes be attacked by the petrol. So you want to avoid running the engine too rich a petrol mix for the former issue, but I'd also not want the petrol sitting around in the system for and extended period either so having topped up with as much diesel as poss already I'd probably do another two or three 1/4 or 1/3 tanks then try and run the tank to near empty so you can fill with fresh fuel and rather than having the petrol hanging around in reduced concentrations for weeks

My [i]friend[/i] did this a few weeks ago. Brimmed an empty tank with unleaded. Dumbass.

He worked it out as he hung the nozzle back up, so didnt start the engine, but got it relayed home by the AA where he could [i]arrange for someone with the necessary certificates to syphon the fuel out and put it in his 200 chainsaws[/i], ahem.

Then went out with some cans to get some diesel and then fire it up. No problems, as petrol never entered the system.

Refilling after using a quarter of the tank

Refill Unleaded Diesel Total % unleaded
0 20.0 55.0 75 27%
1 15.0 60.0 75 20%
2 11.3 63.8 75 15%
3 8.4 66.6 75 11%
4 6.3 68.7 75 8%
5 4.7 70.3 75 6%
6 3.6 71.4 75 5%
7 2.7 72.3 75 4%
8 2.0 73.0 75 3%
9 1.5 73.5 75 2%
10 1.1 73.9 75 2%
11 0.8 74.2 75 1%
12 0.6 74.4 75 1%
13 0.5 74.5 75 1%
14 0.4 74.6 75 0%

Refilling after using three quarters of the tank

Refill Unleaded Diesel Total % unleaded
0 20.0 55.0 75 27%
1 5.0 70.0 75 7%
2 1.3 73.8 75 2%
3 0.3 74.7 75 0%

Your mate sounds like a right ****t. - Hope you laughed at him, whilst trying not to spit coffee over the keyboard.

Is what £100 of diesel really worth the risk ? I'lld get it drained. Tell your mate he's OK to tip the mixture straight down the drain, providing he washes it down with some washing up liquid. 😉

On the basis of the spreadsheets, if you've already started driving it I'd go for the second option (maccruiskeen's).

But on the basis of [url= http://en.wikipedia.org/wiki/Winter_diesel_fuel#Blending ]Wikipedia[/url]

For some diesel motors it is also possible to add even lighter fuels like gasoline to extend the CFPP characteristics. Some car makers were recommending adding up to 20% gasoline to permit operation in cold weather (at the price of higher consumption) and it had been common practice in Europe where No.1 fuel is not offered at gas stations. Since the 1990s car makers began selling only direct injection diesel engines - these will not withstand any gasoline portions in the fuel as the high pressure in the injection device will ignite the gasoline early on possibly destroying the injectors.

I'd get it drained

Interesting, get the pain out of the way then? By mileage it's around 2100 miles v 1350, based on 600 miles-ish per tank
...the diesel molecules will still have the memory of petrol though 🙂

Edit: oh.

it will be fine, i did the same in an old diesel audi i have a few months back, stopped and topped it up with diesel and it was fine, as long as he had some diesel in it will be fine and then top up with diesel as he uses the unleaded.

My dad did this once with his Skoda Octavia (1.9TD, same engine's as the OP's (mate's) van), except he brimmed it with unleaded a day before he was due to tow his caravan back from Penrith area to Burnley.

Not knowing how better to proceed he drove home towing the caravan!! He said that it was all OK at first but was gradually losing power the closer to home he got, but he made it.

My mate picked the car up the following day, took it to his garage, completely drained and flushed the fuel system, filled it with diesel, repressurised it, started it and hey presto! never had a problem since. And that was two years ago.

So I suspect with a 75/25 mix your mate should be OK...

I'd have it drained at over a 1/4 petrol. Modern diesels are expensive to repair. Drain and clean will cost you about £150 a diesel pump at least £1500

park up, remove filler cap and start a small fire under the fuel tank - petrol will preferentially evaporate and viola!, risk-free diesel motoring 😀

Finally, a sensible suggestion 🙂

Would you not be better linking your mate to this thread,save you having to monitor it for him and then relay the information back to you?

I did it in my old Connect. Filled right up with petrol and then went. Drove it on the motorway and it got a bit sluggish on the slip road, then i remembered i wasn't in the car and had just filled with petrol. Then it just stopped.

Had it drained the next morning, new filters plus 20 litres of diesel to flush the lines out all for £150.

End result to make life easier was we got a diesel car too so i don't have to remember if its green or black.

I'd keep it topped up all the time for a couple of weeks. If i'd realised when i was filling up, thats what i'd of done.

Oh, he's keeping an eye on it, don't worry. I'm just here out of concern for him.

Well, my friend rang the local garage where he gets it serviced and they reckon my friend should just keep it topped up.

In fact, they said, had they done the same as my friend and started filling with unleaded, they'd have done exactly what my friend did.

Mmmm . . .

Sounds like a Garage that knows sweet FA about [i]modern[/i] diesels.

Point is you can often get away with it and if you have no intention of keeping the vehicle for any length of time it may not be an issue. However those unit injectors on VW's PD engines are around £300 each.

Go figure - as they say

Hth

Your local garage is probably hoping you'll take the van to them for the engine rebuild.

Are they happy to drop their advice on an email ? - Thought not.

You see, now he's worried again.

A mobile call out to drain the tank's going to cost him £150+ (it's that or a 40 mile drive to the garage, which may charge him less, but would mean running the engine on the dodgy mix), plus the £100 of fuel, so that's at least £250 to get it drained.

That's against what likelihood of it actually causing a problem, given that there seems to be a lot of anecdotal evidence of others doing it with no ill-effect?

EDIT - for what it's worth, I've used the garage for years and trust that they're not trying to screw me.

FWIW, it's a 1.9 turbo diesel T5.

Right. How old? If it's not common-rail, which I think is unlikely unless it's pretty new, you'll be fine I think. Check the user manual, see what it says.

I'd defriend. You don't need idiots like that as mates.

I thought diesel was heavier than petrol. If this is true, will it not sink to the bottom and then be pulled through the pump leaving the unleaded at the top?

Could you not syphon the lot into a paddling pool, light the petrol to burn it off leaving the diesel behind which you then pour back in?
Simples

Its a shame you didnt spend a bit more time messing with old cars, instead of attending school (in particular A level maths) when you were younger. - You could have have helped him out by a doing it yourself and saved a few quid.

I thought diesel was heavier than petrol. If this is true, will it not sink to the bottom and then be pulled through the pump leaving the unleaded at the top?

They mix quite well though.

[i]Right. How old? If it's not common-rail, which I think is unlikely unless it's pretty new, you'll be fine I think.[/i]

54 plate, so one of the early ones. A quick Google suggests the T5's didn't go to Common Rail until 2010.

[i]Its a shame you didnt spend a bit more time messing with old cars, instead of attending school (in particular A level maths) when you were younger. - You could have have helped him out by a doing it yourself and saved a few quid. [/i]

Yeah, but I paid attention at school which is why I go to work in a suit, whilst others still dig holes for a living 🙂

It's possible wear a suit and dig holes for a living you know- look at undertakers.

Whilst I'll grant you that undertakering has its manual side (lifting of coffins etc), the holes in what the coffins are buried have a special name - 'graves' - and the digging of the 'grave' is performed by a separate profession known as, catchily, 'grave diggers'.

Every day, like the say, is a school day.

Early TD and TDI had a separate injector pump which in some cases was fragile and some cases was bombproof - VW tended to be in the latter category.

Then PD was invented by Bosch and used by VW - there's only a low pressure pump and the high pressure stuff is taken care of by a pump mechanism in the injector which is pretty tough afaik. Then with common rail engines they use a super high pressure expensive high tolerance pump, which is a lot more delicate.

So if I go down the 'keep topping up' route, all should be good?

Is it worth sticking any additives in to make up for the anti-lubricant properties of the unleaded?

edit - or, indeed topping up with 'Super' diesel?

Hmm.. additives.. not sure.. you could try putting some engine oil in it, see what happens. Or half-fill it with vegetable oil 🙂

If it were my car I'd chance it, unless I was really worried and had the means to drain a tank and refil with diesel. How far has it been driven?

£150! Blimey. I knew someone who did this the other way round, putting diesel in a petrol. [s]I[/s] He had to call a mechanic after [s]my[/s] his car lost all power and pumped out shed loads of black somke and then stuttered to halt. Mechanic opened up engine by the side of the road and started taking gob-fulls of petrol and spitting them through the injectors and filters, pumped some clean petrol through the system, catching the contaminated fuel in a handy ice-cream tub and selling it on to a passer by... Cost [s]me[/s] him £10. But then again it was in Tanzania...

If it's not common rail just keep adding the diesel to the stuff already in the tank.

I used to add 10% petrol to my non-common rail lump to get it through the MOT and mine didn't have a tough as old boots bosch pump.

Would be a bit smokey/weak as it was rallyed all over the show but the next tank of diesel and the car was loads cleaner and smoother.

If it's a common rail get one of those mobile firms out to remove it and fill with fresh diesel and keep your fingers crossed.

[i]How far has it been driven? [/i]

35 miles, A-road, motorway and bit of stop/start traffic, ran fine. It'll have used about 5 litres, which is what was in the tank before I filled up, so I'm not actually sure if it was sucking through the diesel/unleaded cocktail or not?

It'll have been well mixed already. Diesels have a low pressure pump circuit that sucks up loads of diesel from the tank to the high pressure pump, then that squirts in a finely metered amount - the remainder goes round a loop back into the tank. This tends to mix the fuel nicely, as do corners and whatnot.

It'll probably be fine...

FWIW, it's a 1.9 turbo diesel T5.

PD engine?

Should be fine, you could probably run them on GT85

[i]PD engine?[/i]

Yep, PD.

What's this about sticking some engine oil in? How much?

That was a joke!

It might help lubricate the fuel system a little, but I think the effects will be much less well known than putting petrol in the diesel.

Read the handbook - in my old car it recommended petrol in the diesel in winter, and gave you acceptable ratios.

PD engine?

Should be fine, you could probably run them on GT85

at current prices, that's only a bit more expensive than diesel

FWIW your insurance generally covers you for such mishaps.

PD engines are pretty robust, but... They are expensive to fix if they go wrong.

I've known a number of people get away with a 10:1 diesel:petrol ratio without a problem, but sounds like you've got more like a 3:1 ratio.

I know yours isn't a new Common Rail engine, but... Those PD's still run at very high pressures. A 3:1 mix is too much petrol by some margin I'd say.

I'd chalk this one up to experience. Get it to a garage, get it drained and flushed, and refill with diesel. The cost of getting this done, and the feeling of shame involved, will be FAR more palatable than the cost of fixing anything else if it does go tits up!

Read the handbook - in my old car it recommended petrol in the diesel in winter, and gave you acceptable ratios.

How old was the car?

To be fair, this used to be not only accepted, but recommended. When Diesel engines had a specific output of much less than 50bhp per litre, and would readily run on anything. My old (very first Direct Injection) Mk3 Golf 1.9TDi had 90bhp and would happily run on almost neat veg oil (thinned a little with some petrol and some diesel added) without problem in the summer.

Diesel technology has changed significantly (even by 2004 when the OP's van was built), as has diesel fuel technology. These days you no longer need to put petrol in the tank in the winter cos they've improved the fuel significantly so it is still thin enough in winter without adding petrol (a thinner), and modern diesel engines really don't like having any petrol in them at all!

My car was a 1994 - that's why I suggested the OP check the manual.

Those PD's still run at very high pressures

It's not the pressure that's the issue, it's how the pump works. A PD injector is just a plunger, it's simpler than a CR injection pump afaik. The high pressure pump is what we're worried about here - diesel thinned with petrol might give less lubrication, and the pumps are designed to be lubricated by the fuel.

However it's still probably pretty oily, and you don't have a high pressure pump as such, so my guess is you'll be ok. PD was pretty old tech by 2004.

I'm going to risk it.

To be honest, I’m going to have used about 10 litres by the time I get home anyway, and I’ll fill up then. I’ll do the same tomorrow. And I’m back in Brizzle on Saturday for the bike jumble so I’ll do the same again then so, assuming it’s not blown up by then, it’ll have been pretty well diluted by the weekend and I'll keep filling it daily for a week or so.

If I die you can fight over my bikes.

A PD injector is just a plunger, it's simpler than a CR injection pump afaik.

Sorry, but it's more than that.

Fill yer boots here:

https://docs.google.com/viewer?a=v&q=cache:8zrO_cy6RRIJ:www.myarchive.us/richc/VW_TDI_with_PumpeDuse.pdf+&hl=en&gl=uk&pid=bl&srcid=ADGEEShn0HK8ZAEpv7_qhML6lpRgJJaYGOoNi1sJJemw25y5a3xK-dmGkq7ShdbTzMNoZTs_zyOk4Z-QEoXW0u9EoiWFoMjGw8kKncpkN_HHhEVwU12vhQZ63WV_2fkXZQkvBJDgjIpN&sig=AHIEtbQ8QaiI_AYityGqWvOjpLsI0_6ikA

Hth

"My friend" did this with about 5 litres of unleaded - just kept brimming it with diesel for a few weeks to keep diluting it and no problems since.

Seriously - put a litre of 2 stroke oil in the tank ASAP

This will help with any stress to the pumps and injectors , you can then cary on with the top up regime.

Well...

I drove home, it drove fine, so that's 70 miles on the diesel/unleaded cocktail.

I stuck another 7 litres of diesel in when I got home. It chuntered a bit when I started it again at the petrol station, but, other than that, no probs.

So, fingers still crossed 😕

Ah, I read about 2-stroke. Worth doing then?

syphon what is in the tank out then refill with diesel.
Replace fuel filter then you will only have a minimal amount of petrol in the mixed fuel that is in your fuel lines, you can even bleed that out if you want.

I put a tenners worth of unleaded in my t4 3 yrs ago by accident. Brimmed the tank and then kept it full with regular top ups. No ill effects.

Well...

I drove it the 35 miles to work after brimming it - no issues
Drove it the 35 miles back - no issues
Brimmed with another 7 litres of diesel when I got home - it grumbled/struggled a bit starting again from hot at the garage, but once going was fine.
Drove it ten miles this morning to clear about a litre from the tank and stuck a litre of 2-stroke in - again, grumbled starting again from hot
Remaining 25 miles to work - no issues

It's now sitting in the work car park with the filler cap off, hoping that some of the unleaded will evaporate off. Shame it's a bloody freezing day...

I'll fill it again with another 7 or so litres after the 35 mile drive home tonight (or maybe in the morning, then I don't have to start it from hot at the garage). Same again tomorrow as I'm doing another 70 mile run, and then same through the next week.

Fingers crossed, but I think the bullet has been dodged 😕

Fingers crossed, but I think the bullet has been dodged

Errm, your friend, shirley? 🙂

Well done, good result.

Ahem. Yes, yes, of course, my friend did all those things 🙂

I'd pop out and put the cap back on as that'll have no effect. Once mixed, and it is by now, the Van der Waal's forces (or London dispersion forces if you prefer) will make it nigh on impossible for the petrol fraction to just evaporate off.

Pressure might be an issue as the petrol would auto-ignite at lower pressure.

But then I would think IHN ('s mate) has demonstrated that there have been no short term effects.

I did this to my wife's car.

We had it drained, and I kept the fuel and used it in my petrol car.

Both ran fine afterwards.

Does the harder starting not mean that something is up?

Nah, I don't think so. It's only when it's hot, and I think it's because the mixture is 'thinner' as the unleaded evaporates off. From cold it starts fine.

From reading round it's a common thing with others who've done the same as my friend.

Then PD was invented by Bosch and used by VW -

I thought FIAT invented it, and sold it to the Germans when they ran out of money (again).

Bit like the current Iralian economy!

Petrol is less dense than diesel so it will sit on top of the diesel in the fuel tank. If you leave your filler cap off the petrol will evapourate eventually.

[i] If you leave your filler cap off the petrol will evapourate eventually.[/i]

My fuel tank filler tube has a non-return valve in it.

My fuel tank filler tube has a non-return valve in it.

Fuel vapour wont close the non return value

and stuck a litre of 2-stroke in

That's not a bad idea, could maybe have done it straight away.

I bet you got some funny looks doing it though 🙂

NRAPs but doesn't your breakdown cover the draining of tanks? If you have that is...