Petrol in a Diesel Car in Bangor: How Worried Should You Be?
Not started? Then less worried than you probably feel. "Have I wrecked it?" is the first question anyone in Bangor asks, and the truthful answer is generally no, since petrol left in a diesel tank hurts nothing till it's drawn through the system — by ignition priming, by the starter, or by driving. Petrol in Diesel is who to phone, with your motor left off, and so it stays that way. What petrol actually does to a diesel, how to judge how far it has travelled, and how to stop it from happening again: that's the remainder of this page.
The engine and petrol in a diesel: what happens
Diesel does two tasks on its way through a motor. It lubricates to begin with, and only then does it burn. Your high-pressure pump and the fuel injectors are made to extremely fine tolerances, and your diesel passing through them is what stops those surfaces from grinding against one another.
Badly at the first, not at all at the second: that is petrol. A pump running on a petrol mixture is wearing itself out, because petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that's where the clattering comes.
Put these together and the shape of the problem is plain. Not contact but circulation is what causes the damage. Where the petrol is only inside your tank, it's an issue of fuel, nothing more. Once the pump has been working on that petrol, a mechanical problem has started: whatever is shed by a pump that is wearing travels downstream to your injectors with the fuel.
Petrol in a diesel around Bangor: how serious is it? Four situations
Fuelled, and never started: nothing beats it. Only the tank has petrol in it, so the task is draining your tank and flushing the system where the car stands. This scenario can only truly happen on a forecourt: anywhere else, the car got there by being driven.
Started for a second, or just the ignition on. Petrol has left your tank and reached the filter and the fuel lines, because your system has been primed. Drain, flush, deal with the fuel filter: still usually simple.
A few miles driven, and the pump has spent each of them running on weakened fuel. Distance is only half of that; how hard it was driven counts just as much. Either way the work includes that tank, your lines, your filter and clean fuel through the whole circuit. Driving the children to the local primary school is one kind of trip. Any mileage on the Moreton Spur, under 50 miles from Bangor, means your engine working hard throughout, and a run to St Asaph, under 50 miles away, is a very different task as well.
Rattling, a ragged idle, smoke, a throttle gone soft: driven till it complained. That is the motor telling you its fuel no longer is acting like diesel. Pull up wherever you are — the verge on Ffordd Gwynedd, a lay-by, a side street — then leave the car there. Permanent damage is very unusual if a vehicle is pulled over quickly, and the fuel drain and flush-through that still go first deal with it.
Bangor drivers and the petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you're left with a fuller tank, still the same mix. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. Smaller parts and higher pressure are the way a modern diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that catches people. Myth: "If it starts and drives, there is no harm done." Diesel in a petrol motor normally leaves a motor that won't run: the driver stops, and so does the harm. Feed petrol to a diesel and it normally fires up, idles and drives away like nothing has happened — all the while its pump wears. Fine and running aren't the same at all.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different fault. The petrol is still in the tank after that, and what it has thinned isn't put back.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the fuel filter and lines, waiting to go right back through the pump on the next start. It is also genuinely dangerous to drain petrol into a can at the kerbside.
How does petrol in a diesel occur?
Nobody does it on purpose, and it is seldom carelessness. One way only, since of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol motor. That is how the forecourt makes it simple.
Routine and your car getting out of step is when it happens. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. Your normal forecourt, its pumps suddenly in a different order. A hurried fill on the way to Bangor (Gwynedd) with a train to catch. The first fill-up in a diesel Volkswagen Tiguan after years of driving petrol is precisely the moment it takes place. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Bangor drivers: how to avoid petrol in a diesel next time
- The label is what matters, so check the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on every forecourt.
- Check your filler flap. Many cars state the fuel type inside the flap or on the cap. Look at it on your first fill in a motor you do not know.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key if a home has one of each. So label it.
- Before the nozzle leaves the petrol pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Silly, yes, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so put your phone away and keep your mind on the petrol pump.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that will not take a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol inside the tank makes a thinner mixture. What to do next doesn't change, though — still do not fire it up.
Petrol already in a diesel around Bangor? Start here
Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off too. If you are still on the forecourt — Asda or anywhere else — ask the attendants to help you push it clear of the petrol pump. Then call 0333 366 0103 and tell us what went in, about how much, and if it's run.
If it was AdBlue rather than petrol, say so. That is a different fault — corrosion and deposits instead of lost lubrication — and it has its own page for Bangor.
Why one petrol in a diesel job around Bangor costs more than another
Four separate tasks lie behind the four scenarios above — which is why there's no fair single price. Which of them you're in is mostly what shifts the cost. Beyond that it is the proportion — how much petrol got in against how much the tank holds — and after that where your car is and whether a technician can reach it safely.
Ahead of any quote, not after, come three questions: the fuel that was put in, its volume, and whether it has run. That is why. A range turns into a straight figure once those answers are in.
About Bangor and where it is
Bangor is a city situated on the coast of Wales, within the county of Gwynedd. It is characterised by its historic and educational significance, being home to a prominent cathedral and a well-known university. The city's location is notable for its proximity to the Isle of Anglesey, which is accessible via major bridges. Bangor's coastal setting and notable landmarks make it a distinctive place in northwest Wales.
Bangor and Gwynedd: where our fuel drain cover reaches
Petrol in diesel call-outs around Bangor — part of the LL postcode area — go to vans that also cover the spots round it, Upper Bangor, Hirael and Garth among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and the car does not need to move to us.
Bangor: still at the petrol pump?
Then you're in the best place there is. Phone, and keep it switched off.