Half filled diesel car with unleaded, rest with petrol

roryc

Went to fill up the car after work, stressful day so wasn't looking at what I was doing... put £20 unleaded in before I realised my mistake, then panicked and filled up the rest with diesel (£19)... its pretty much half petrol/half diesel.

I've never made this mistake before but 7 years of driving unleaded cars and only swapped over to diesel when i moved to Spain.

Anyway, guy in petrol station said putting unleaded in a diesel isn't as bad as the other way around, and I should be ok so I drove home no problem, left it a few minutes now its struggling to start. Tried putting a hose in to empty the tank but wont work as it has a stopper in it, presumably to stop people nicking your petrol.

Its struggling to start already and I don't wanna do anymore damage, but my Spanish isn't great so calling a tow truck is out of the question, have no ph number anyway.

Is it worth the risk to drive it in to Gibraltar (where I work), which is about 10-15k away, where they will have English speaking mechanics and I can get the tank drained?

Reading online is making me think I've already f*cked it, while other people are saying I might be ok...

I need to get this fixed ASAP, have to drive 120k to Malaga on Thursday morning for a flight home which I cannot miss.


Appreciate any advice...

Mr Benevolent

What model and engine do you have? Anything before (roughly) 2005 should be ok

roryc

1998 Seat Ibiza... Only a small car, £40 filled the tank.

Do you think its worth risking driving in the morning? Dont fancy paying a £100+ towing fee on top of everything else for a car thats only worth £1k

Cheers mate

Mr Benevolent

It'll probably be fine. Top up with as much diesel as you can when there's a bit of space in the tank. Petrol can be surprisingly good at cleaning diesel engine internals too

roryc

So you dont even think I should get it drained? Are you a mechanic

Thanks for the advice btw, just cant **** this car up, really need it for Thursday for a long drive...

Nissan doctor

You won't do any damage on an older diesel, the reason it is sluggish to start is simply that petrol doesn't ignite the same a diesel.

The simplest and least technical solution is to take it out and drive around just to use the fuel, everytime you get to say 3/4 tank, fill it back up with diesel and so on..

roryc

But does a 1998 seat ibiza count as an old car? Its new enough to have the stopper in the fuel tank, so Id presume its new enough to do damage?

Thanks again for the advice, but is it really not a big risk to drive 20k and then get it drained?

Nissan doctor

roryc wrote: »

But does a 1998 seat ibiza count as an old car? Its new enough to have the stopper in the fuel tank, so Id presume its new enough to do damage?

Thanks again for the advice, but is it really not a big risk to drive 20k and then get it drained?

The engine fitted in a 98 ibiza would be the pre PD vag unit, so old technology.

You can of course pay to have it drained, it will travel 20kms although not overly smoothly, but in the DIY section we're trying to advise you on a DIY solution..:)

roryc

Apologies, didn't even realise this was the DIY section

So honest opinion, you think I should just drive it off and keep refilling with diesel? What are the realistic chances of this working...

Mr Benevolent

roryc wrote: »

Apologies, didn't even realise this was the DIY section

So honest opinion, you think I should just drive it off and keep refilling with diesel? What are the realistic chances of this working...

100%. Old VAG diesels are very reliable, they'll run on anything. If you want to keep the cost down, do nothing and it'll be fine.

Nissan doctor

roryc wrote: »

Apologies, didn't even realise this was the DIY section

So honest opinion, you think I should just drive it off and keep refilling with diesel? What are the realistic chances of this working...

No chance involved....it will work.

-Corkie-

Nissan doctor wrote: »

No chance involved....it will work.

+1 if OP had a 08 CR Seat diesel he would be in serious trouble. The Joys of driving a banger!!:D

_Conrad_

Confab wrote: »

It'll probably be fine. Top up with as much diesel as you can when there's a bit of space in the tank. Petrol can be surprisingly good at cleaning diesel engine internals too

No, just no. petrol is NOT good in a diesel engine at all

roryc

So Conrad, what would you recommend? Do you think driving the petrol out can work?

faw1tytowers

I did this before too but it was more 20/40 petrol into a diesel engine. But a said I just kept topping up and no issues.

_Conrad_

roryc wrote: »

So Conrad, what would you recommend? Do you think driving the petrol out can work?

I recommend draining the tank to be honest. If there's enough diesel in it to "dilute" the petrol it will run and drive but it will run badly and be very smokey, and it's also not good for the engine at all to run it on the wrong fuel.

But yes, if you have enough diesel compared to petrol it will eventually burn it all and you'll end up being able to fill up with pure diesel again, but it's a much better idea not to run a diesel car on petrol or the other way round. You can "drive it out" if you want but the proper thing to do would be remove the contaminated fuel

BanzaiBk

Personally I'd do the constant top-ups with diesel myself. Had a similar issue with a pre-pd engine and it struggled but once the unleaded was burned off it was absolutely fine. There's a fairly decent english speaking mechanic on the Gib side of Estepona but he could screw you pricewise for the privilege.

Buford T Justice

In fairness, Nissan Doctor hasn't steered anyone wrong on this forum yet to my knowledge, so it'd be fine.

If you had a modern diesel engine then it would be a different story, but you don't. Drive it out & keep topping it up, it'll be fine.

roryc

Thanks for the advice so far lads...

Got up this morning at 6:30am and went for a looooooong drive. No white smoke and the car is driving perfectly, once it starts. Each time I turn it off its struggling more and more to start, as the engine gets flooded with unleaded when I turn the ignition.

I ran down almost 1/3 of the tank and refilled it with diesel, so I figure the ratio now is almost 2:1 Diesel:Petrol... Fingers crossed it starts after work today.


If I can get it home Ill park it on the almost 90 degree hill outside our apartments so the engine drains. Hopefully this will be enough to start it in the morning and get me to Malaga...

Is there anything I can do now to make my chances any better? How can I avoid flooding the engine before starting, and if I do, is there anything I can do after this? I usually turn the key almost the full way before starting, as I think this opens the pipes/valves and for some reason is good for the car...


Thanks again all...

Leonard Hofstadter

Glad you got on ok, those old VAG diesels are great old engines, give them a service every now and again and they will outlive the rest of the car, if it was a modern PD or CR diesel, even a drop of petrol could make minced meat of the injectors and other components. The engine will be fine, I wouldn't worry about doing any damage, it's a diesel from the days when diesels were bulletproof.

As the others said, keep refilling it with diesel to dilute the mixture.

The joys of old fashioned diesel engines, huh;)?

roryc

Yeh it seems to be driving perfectly, no white smoke at all and no strange noises... the only thing Im worried about is how much its struggling starting.

Is there anything I can do to avoid flooding the engine? Also, will parking on a hill (with the engine at a higher point than the fuel tank) do me any favours? My thinking is it will drain the engine and give it a better chance of pulling in the new 'diesel-heavy' mixture of fuel...

Harcrid

It will struggle to start while the remains of the unleaded are still in the system. Just keep topping up as often as you can and eventually you will be back to pure diesel.

roryc

What if it just wont start at all? This is my biggest worry at the moment tbh... Once it starts it runs perfect, just been struggling more and more to start.

Someone told me if its not starting get a can of easy start aerosol (or WD40), remove air filter and spray direct in.

Does that sound about right?

whizbang

poor starting is caused by petrol vapours building up in places where diesel would normally not.
dont know this yoke, but if it has a primer pump, a few presses should do it. also check for air/water bleed at the filter, and drain off a spoonful.
Park it facing downhill, -heaver diesel

roryc

whizbang wrote: »

poor starting is caused by petrol vapours building up in places where diesel would normally not.
dont know this yoke, but if it has a primer pump, a few presses should do it. also check for air/water bleed at the filter, and drain off a spoonful.
Park it facing downhill, -heaver diesel

Downhill? I have it parked facing uphill... on a steep hill

Slidey

Parking it up or downhill will make no difference what so ever.

Stay away from easy start, as you do not know what you are doing you will only end up doing damage

Wossack

I'd have it parked pointing downhill, only just so you can more easily bump it if you flatten the battery

roryc

Cheers lads, managed to get it up to Malaga on Friday and left it there over the weekend. Started up ok this morning after a little bit of a struggle. Same as last week, driving not a problem.

Stopped off in Marbella on the way back to drop a friend off and had major trouble restarting... took about 5 seconds before the engine finally slowly began to turn over. By this stage the tank was down to about half again so I refilled... with Diesel

By my calculations there should only be between 20-25% of the (full) tank in unleaded. Leaving the petrol station it was again struggling to start.

I also noticed something which may be an issue... when I normally start the car an orange light comes on on the dash for a second or two - as far as I know this is for the glow plugs heating up? I always wait until this goes off before starting the engine, however, althoughit lit up this morning it hasnt done so since. Since that light has disappeared it has been harder to start.

Could the glow plugs have burned out/need replacing?

Thanks!

Foleyart

Glow plugs and petrol in the tank two seperate issues. If it is slow starting, it is probably a glow plug problem anyway. Not a big job to change them out. Hope it works out ok for you. Ive put petrol in a diesel car before and had no problems with it, top up and away ya go.

evosteo

Stay away from easy start, as you do not know what you are doing you will only end up doing damage

why do you say that, what sort of damage can it do????

slade_x

Probably a bit late

http://www.aaireland.ie/AA/AA-Membership/Fuel-Assist.aspx

Effects of mis-fuelling

• Diesel fuel pumps operate on very fine tolerances and are lubricated by the diesel fuel itself.
• Petrol in diesel acts as a solvent – it reduces lubrication and can cause damage to the pump through metal to metal contact.
• The further the contaminated petrol goes in the system the more expensive the repair – it can be cheaper in more extreme cases to fit a new engine.
• The newer common rail (or HDi) diesel engines are particularly vulnerable – if fuel contaminated by pump wear debris gets as far as the common rail system you may have to replace the low and high-pressure fuel pumps, injectors, fuel rail, line filters and the fuel tank too.
• Many systems use a low-pressure electric pump in the tank or sender unit and this begins to work as soon as the ignition is switched on, circulating the contaminated fuel through the pump and rail – so it's important not to turn the ignition on.
• Damage to the engine can be very expensive for some vehicle owners: manufacturers often:
  • recommend change of parts (as high as €2,000* or more) and
  • garages often charge €440* or more for a fuel drain

Petrol In Diesel

• Do not turn on the ignition or start the car
• If the car's still under warranty you should check with the franchised dealer regarding their advice and correct remedial action – running with even a small amount of petrol in the tank might invalidate the warranty while some manufacturers advise that seals and filters should be renewed even if the engine has not been run.
• Generally a small amount of incorrect fuel should not damage the engine as long as you have not started the car and top up fully with diesel fuel.
• If you've added more than 10% (5 litres in a 50 litre tank) petrol - Drain the tank and refill with diesel
• If you've added less than 10% petrol (5 litres in a 50 litre tank) – Top up with diesel and run normally unless the manufacturer has advised otherwise

Diesel In Petrol

• Do not turn on the ignition or start the car
• This is much less common because the standard diesel nozzle at fuel stations is larger than the fuel filler neck on modern petrol cars – you have to be pretty determined and patient to mis-fuel with diesel as a result.
• If the car's still under warranty you should check with the franchised dealer regarding their advice and correct remedial action.
• Generally a small amount of incorrect fuel should not damage the engine as long as you have not started the car top up fully with petrol.
• If you've added more than 10% (5 litres in a 50 litre tank) diesel – the car shouldn't be run and the tank should be drained
• If you've added less than 10% (5 litres in a 50 litre tank) diesel – the tank can be topped up with petrol and the car run normally unless the manufacturer has advised otherwise