Ashfield: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, worry less than you likely are. "Have I wrecked it?" is the first question anyone in Ashfield asks, and the honest answer is generally no, since petrol left in a diesel tank harms nothing till it's dragged through your fuel system — by ignition priming, by the starter, or by driving. Leave your motor off then call Petrol in Diesel — that keeps it that way. The remainder of this page covers what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
The motor and petrol in a diesel: what goes on
On its way through an engine, diesel does two jobs. It combusts, and before it combusts it lubricates. The high-pressure pump and the fuel injectors are designed to very fine clearances, and your diesel passing through them is what keeps those surfaces from wearing down against one another.
Poorly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump on the blend wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
The shape of the trouble is clear when you put those together. Contact does not do the harm — movement does. All a tank with petrol in it amounts to is a fuel fault. Once your pump has been running on that petrol, a mechanical fault has begun: anything shed by a pump that's grinding is carried onward to your injectors with the fuel.
Ashfield, petrol in a diesel: four situations, from mild to major
Fuelled, and not started: no case is better. The petrol is in your tank and only your tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only truly happen on a forecourt, since anywhere else the vehicle has been driven to get there.
Started for a second, or just your ignition on. Once primed, your system has drawn petrol from the tank up to the fuel filter and the lines. Drain, flush, deal with the fuel filter: still normally easy.
Those few miles driven were the pump labouring on fuel diluted by petrol throughout. Tank, lines, filter, then clean fuel run through the entire circuit: that's this work, and the way the vehicle was driven matters as much as the distance. On the school run to St Joseph's RC Primary School and Nursery, the mileage is short. Very different again: a trip to Hereford, under 15 miles away, or any miles on the M50, under 3 miles from Ashfield, where your engine kept running hard.
Driven till it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the motor is telling you. Pull up wherever you are — the verge on Walford Road, a lay-by, a side street — and leave the vehicle there. What comes first is still the drain and flush, and that deals with it, with long-term damage very uncommon if a car is pulled over quickly.
Ashfield motorists and that petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Topping up removes nothing; it gives you a bigger tank of the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Smaller components and higher pressure are how a newer diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there is no damage done." Diesel in a petrol motor generally means a motor that won't run: the driver stops, and so does the harm. Whilst the pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. A running engine does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate problem. The petrol is still inside the tank afterwards, and what it has diluted isn't put back.
The next start sends petrol back round your pump from the fuel lines and the fuel filter, where some of that sits after the motor has been run. That is why a DIY tank drain doesn't sort it — a myth. On top of that, petrol drained into a can by the road is genuinely hazardous.
Petrol in a diesel: how does it happen?
Nobody does it on purpose, and it's rarely carelessness. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol car. That is how the forecourt makes it easy.
It occurs when routine and the vehicle stop matching. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. The pumps in a different order on a familiar forecourt. Rushing for a train outside Ledbury and fuelling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: precisely when it occurs. With rain, a call arriving, or children to deal with, the hand simply does what it has always done.
Avoiding petrol in a diesel next time you fill up in Ashfield
- Read the pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on each forecourt. The label is what counts.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before your first fill: many vehicles state the fuel type there.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump. It sounds silly and it works.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop reading the pump.
- Less petrol means a thinner mix, so stop the moment you notice — though remembering that the next stage is unchanged. It's still not to start the vehicle.
Already put petrol in a diesel around Ashfield?
Then, there's only a short order of things. Starting it is out, and so is switching on your ignition. Yet at the forecourt, at Morrisons or anywhere else? Ask the staff to help you roll it clear of the pump. Call 0333 366 0103 next, with three facts — the fuel, the approximate quantity, and whether it has run.
If it was AdBlue instead of petrol, say so. That is a different issue — corrosion and deposits and not lost lubrication — and it has its own page for Ashfield.
Ashfield petrol in a diesel tasks: why one costs more than another
Four different tasks lie behind the four scenarios above — which is why there's no fair single quote. Chiefly, your cost moves with which situation you are in. Beyond that it is the ratio — how much petrol was put in against how much your tank holds — and then where your car is and whether our van can reach it safely.
That is why our technicians ask three queries before costing instead of after: what got in, how much, and if it has run. Their replies are what change a range into one firm number.
About Ashfield
Ashfield is a suburban area situated on the riverside in Herefordshire, with a relatively low elevation of 71 metres. Ashfield lies near several notable places, including Ross-on-Wye and Archenfield, and is approximately 11.5 miles from the city of Hereford. Ashfield has a population of around 3723 people and is characterised by predominantly detached housing.
Fuel drain cover across Herefordshire, Ashfield included
Our vans answering petrol in diesel jobs around Ashfield, in the HR postcode area, also work the locations around it, Ross-on-Wye, Archenfield and Merrivale included. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Still at the pump in Ashfield?
No position is better: that is where you now are. Keep it off. Phone.