Should You Worry? Petrol in a Diesel Car in Llangernyw
Provided it has not been started, you can worry less than you probably are. Petrol sitting in a diesel tank does nothing to the motor until something draws it through your fuel system — your ignition priming your pump, the starter, or driving on its own. So the fair answer to the first question anyone in Llangernyw asks, "have I ruined it?", is normally no. To leave it like that, phone Petrol in Diesel and leave the motor switched off. What petrol really does to a diesel, how to judge how far it has travelled, and how to stop it from happening a second time: that is the rest of this page.
Inside your engine: what petrol in a diesel does
Passing through an engine, diesel is doing two things at once. Before it combusts, it lubricates — and then it combusts. Your high-pressure pump and the injectors are built to very fine clearances, and your diesel passing through them is what stops those surfaces from wearing against each other.
Petrol does the first task badly and the second not at all. The rattling comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection your system hinges on, and any pump running on that mixture is wearing itself.
Put these together and the shape of the issue is clear. It's circulation that does the damage, not contact. Petrol in a tank is a fuel fault. After your pump has been running on that petrol, a mechanical fault has begun: whatever is shed by a pump that is wearing down travels onward to the injectors with the fuel.
Llangernyw, petrol in a diesel: four cases, from mild to serious
Filled up, and not started: no case is better. Just that tank has petrol in it, and so the job is clearing the tank and flushing your system where your car stands. This scenario can only really take place at a forecourt: anywhere else, the car got there by being driven.
The ignition turned on, or a short start. Petrol has left the tank and got to the filter and your lines, since your system has been bled. Still normally straightforward: drain, flush, and your filter seen to.
Driven a couple of miles. Now your pump has spent those miles labouring on diluted fuel. How hard the car was driven counts as much as how far, and the work takes in your tank, the lines, your filter and fresh fuel through the whole system. Driving the children to the local primary school is one kind of trip. Very different again: a run to St Asaph, under 15 miles away, or any mileage on the Moreton Spur, under 50 miles from Llangernyw, where the motor kept running hard.
Driven till it complained. Clattering, a ragged idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the engine is telling you. Whether it's the verge on Y Fedwen Arian, a lay-by or a side street, stop where you are then leave it. Permanent damage is very uncommon if a car is pulled over quickly, and the drain and flush-through that still go first deal with it.
What Llangernyw motorists get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Topping up removes nothing; it gives you a bigger tank of the same mixture. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. Rather, the opposite. Protection matters more on newer diesels, not less, since their fuel passes through more precise components at higher pressure.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor generally leaves a motor that won't run: the motorist stops, and so does the harm. Feed petrol to a diesel and it normally fires up, idles and drives away as if nothing happened — all while its pump is wearing. Running isn't the same as fine.
Myth: a two-stroke additive makes it safe to drive home. It was an old fix, supposed for another problem. That petrol is still in that tank after that, and whatever it has weakened isn't put back.
The next start draws petrol back round the pump out of the fuel lines and the filter, where some of that sits after your engine has run. That's why draining your tank yourself does not sort it — a myth. It's also truly hazardous to drain petrol into a can by the roadside.
Petrol in a diesel: how does it take place?
A careless moment is rarely the cause, and no one means to do it. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol car. That is how the forecourt makes it simple.
It occurs when habit and your car stop matching. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Filling up in a rush on the way to North Llanrwst, with a train to catch. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Throw in rain, a phone call or a back seat full of children, and your hand does what it has always done.
Avoiding petrol in a diesel next time you fill up in Llangernyw
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a strange motor is the time to check your filler flap — inside it, or on the cap, many vehicles state the fuel to use.
- Label your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems silly. It works.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices exist for motors without one. They are a backstop, not a reason to stop reading the petrol pump.
- Less petrol makes a weaker blend, so stop as soon as you notice — while remembering that your next stage is unchanged. It is still not to fire it up.
Already put petrol in a diesel around Llangernyw?
The order of things is brief, then. Do not turn the ignition on, and don't start it. The staff at the forecourt — whether at the nearest petrol station itself or wherever you filled up — will normally help roll it clear of the pump if you ask. Then ring 0333 366 0103 and tell us what was put in, about how much, and if it has run.
If it was AdBlue and not petrol, say so. That's a separate problem — corrosion and deposits and not lost protection — and it has its own page for Llangernyw.
What makes one Llangernyw petrol in a diesel task cost more than the next
Four different tasks lie behind the four scenarios above — which is why there is no honest single quote. Which of them you're in is mostly what shifts your cost. Where the vehicle is matters too, and whether a technician can safely get to it, after the proportion of petrol to what your tank takes.
That is why our engineers ask three questions before quoting rather than after: what was put in, how much, and if it's run. With those replies, you get a straight figure rather than a range.
About Llangernyw itself
Llangernyw is a village in Conwy, Wales, situated on the banks of a river at an elevation of around 160 metres. Llangernyw has a population of approximately 697 people and is characterised by predominantly detached housing. Llangernyw is located near several smaller settlements, including Hendre-ddu, Pentre Isaf, and Tan-y-Graig, and is about 11 miles from the city of St Asaph.
Llangernyw and Conwy: where our fuel drain cover runs
Llangernyw rests in the LL postcode area, and the vans that answer petrol in diesel call-outs there work the locations near it as well — Hendre-ddu, Pentre Isaf and Tan-y-Graig among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our technicians drain, and the vehicle does not need to come to us.
In Llangernyw and still at the pump?
Then you're in the best position there can be. Keep the vehicle turned off, and ring.