Petrol in a Diesel Car in Wigmore: How Worried Should You Be?
Provided it has not been started, worry less than you probably are. Everyone around Wigmore starts with "have I wrecked it?", and the honest answer is usually no: petrol resting inside your tank of a diesel remains harmless till priming, cranking or driving pulls it into the system. Leave your engine off and call Petrol in Diesel — that is how you keep it like that. What petrol really does to a diesel, how to judge how far it's gone, and how to keep it from happening a second time: that's the remainder of this page.
Petrol in a diesel: what does it do to your engine?
Two tasks fall to diesel on its route through a motor. Before it burns, it lubricates — and then it combusts. Designed to very fine gaps, the injectors and your pump depend on your diesel moving through them to stop their surfaces wearing against one another.
Poorly at the first, not at all at the second: that is petrol. A pump working on a petrol mix is wearing itself out, because petrol is runnier than diesel and takes away the protection your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where any rattling starts.
The shape of the trouble is clear once you put those together. Contact doesn't do the damage — circulation does. All a tank with petrol in it amounts to is a fuel fault. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
Four scenarios our technicians see in Wigmore: how bad is petrol in a diesel?
Fuelled, and never started: no case is better. On a forecourt, and truly only there, the petrol is still limited to the tank — because anywhere else your car was driven to reach it. The job is draining and purging on the spot.
Ignition on, or started for a moment. With the system primed, the lines and filter now contain petrol that came from that tank. Usually little more than clearing, cleaning and sorting your filter, and so still straightforward.
Driven a few miles. Now your pump has spent these miles working on diluted fuel. How hard your car was driven counts as much as how far, and the work covers the tank, your lines, the filter and clean fuel through the whole circuit. On the school run to Wigmore Primary School, the miles is small. Very different once more: a run to Hereford, under 25 miles away, or some distance on the M54, under 50 miles from Wigmore, where the motor kept labouring hard.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The motor is telling you the fuel is no longer acting like diesel. Stop wherever you are — the verge on Glen View, a lay-by, a side street — and leave the vehicle where it is. Lasting damage is very uncommon if a car is stopped quickly, and the drain and flush-through that still go first sort it out.
What Wigmore people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing comes out when you top up — your tank just holds more of the same mixture. Percentage isn't how a diesel fuel system copes with petrol, whatever that guidance supposes.
Myth: a modern diesel copes with a bit of petrol. Rather, the reverse. Lubrication counts more on newer diesels, not less, since their fuel passes through finer components at higher pressure.
One myth that catches motorists off guard: if it starts and drives, it must be unharmed. The motorist of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the damage stops with them. Feed petrol to a diesel and it generally fires up, ticks over and pulls away as if nothing happened — all the while its pump is wearing. Fine and running aren't the same thing.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate problem. It does not put back what petrol has diluted, and the petrol is still inside your tank later.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in your filter and lines, ready to go straight back through the pump on your next start. And, a can of petrol filled at the kerbside is genuinely dangerous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
When routine and the vehicle stop matching, it happens. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps suddenly in a different order. Filling up in a rush on the way to Bucknell, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Add a back seat full of children, a phone call or rain, and habit wins.
How to prevent petrol in a diesel at your next fill-up around Wigmore
- A green handle for unleaded and black for diesel is usual in the UK — but not on every forecourt. Go by the label on the pump, not the colour.
- The first fill in an unfamiliar vehicle is the time to check your filler flap — inside it, or on the cap, plenty of vehicles state which fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key if a house has one of each. So mark it.
- It seems silly and it works: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes away.
- Some diesels have a filler built to reject a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the pump.
- Stop as soon as you notice. Less petrol in that tank means a thinner mix. It doesn't change what to do next, which is still not to start the car.
Petrol already in a diesel around Wigmore? Begin here
The order of things is short, then. Leave it unstarted, with the ignition switched off too. If you're still on the forecourt — Essar or anywhere else — ask the staff to help you roll it clear of the pump. Call 0333 366 0103 next, with three answers — your fuel, the approximate amount, and if it has run.
If it was AdBlue rather than petrol, say so. That is a different fault — corrosion and deposits rather than lost lubrication — and it has its own page for Wigmore.
One petrol in a diesel job around Wigmore costs more than another. Why?
The four scenarios above are four separate jobs, so no single quote for this would be fair. Which of them you're in is chiefly what moves your cost. Two things follow that: the petrol that got in as a share of what that tank takes, then the place your car is in and whether a van can reach it safely.
Ahead of any quote, not after, we ask three queries: your fuel that got in, its amount, and if it's run. That is why. Those answers are what turn a range into one firm number.
About Wigmore, briefly
Wigmore is a village in north Herefordshire, situated on the banks of the River Lugg at an elevation of around 129 metres. Wigmore lies approximately 18 miles northwest of Hereford and some 129 miles west of London, within a rural area that includes nearby settlements like Leinthall Starkes and Yatton. Wigmore has a mix of housing types, but semi-detached homes are particularly prevalent in the village. Wigmore remains a small, close-knit community with a population of around 527 residents.
Fuel drain cover across Herefordshire, Wigmore included
Leinthall Starkes, Yatton and Lower Lye are among the spots around Wigmore that the same vans work, answering petrol in diesel call-outs across Wigmore's HR postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our engineers drain, and your vehicle does not need to come to us.
At the petrol pump in Wigmore, still?
Then, you could not be in a better spot. Turned off it stays; then call.