Should You Worry? Petrol in a Diesel Car in Wiswell
Less than you probably are, provided it has not been started. Till your ignition primes the pump, your starter cranks, or your vehicle is driven, petrol in a diesel tank just waits there and does nothing. Which makes the truthful reply to that first Wiswell query — "have I wrecked it?" — usually no. Keep it that way: leave your motor off and call Petrol in Diesel. Below, you will find what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the motor?
Passing through an engine, diesel does two things at the same time. It protects to begin with, and only then does it burn. Your 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 against one another.
Poorly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the blend wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the knocking.
Together, those leave the shape of the trouble clear. It's movement that causes the harm, not contact. A tank with petrol in it is a fuel issue. Once your pump has been labouring on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing is carried onward to your injectors with the fuel.
How bad is petrol in a diesel? Four scenarios our technicians see around Wiswell
Filled but not once started — as good as it gets. Just your tank has petrol in it, and so the task is draining that tank and purging the fuel system where the car sits. This situation can only really take place at a forecourt: anywhere else, your car got there by being driven.
Your ignition turned on, or a short start. Once primed, your system has pulled petrol from the tank as far as your filter and the lines. Still normally easy: drain, flush, and the filter sorted.
Driven a few miles. Now the pump has spent these miles running on thinned fuel. Tank, lines, filter, then fresh fuel put through the whole system: that is this work, and the way your car was driven matters as much as the distance. On the school run to Barrow URC Primary School, the mileage is small. A run as far as Preston, under 15 miles away, is a very different job. So is any mileage on the M65, under 5 miles from Wiswell, where the engine has been working hard the whole time.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is your motor signalling fuel that no longer runs like diesel. Stop on the spot — on the verge on Leys Close, at the kerb, down a side road — and don't move it. Lasting damage is very uncommon if a vehicle is stopped quickly, and the drain and flush-through that still go first take care of it.
What Wiswell motorists get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. That advice presumes a diesel fuel system handles petrol by percentage. It does not.
Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through more precise components: that's how a modern diesel handles its fuel, so the protection counts for more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the damage stops there. While the pump wears, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Running is not the same as fine.
Myth: a two-stroke additive lets you to drive home. It was an old fix, supposed for another problem. What petrol has diluted remains weakened, and that petrol stays inside the tank anyway.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in your filter and lines, waiting to go right back through the pump on your next start. Draining petrol into a can by the roadside is also genuinely hazardous.
Why petrol in a diesel occurs at all
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle generally won't go into a petrol motor, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and only in that direction.
Routine and the vehicle falling out of step is how it takes place. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. A forecourt you know, but with its pumps laid out differently. Racing for a train at Whalley and filling up en route. A new-to-you diesel Renault Clio, its first fuelling, and a motorist used to petrol: exactly when it happens. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
How to prevent petrol in a diesel on your next fill-up in Wiswell
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what counts.
- In a motor you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of vehicles print the fuel type there.
- One of each in the house? Label the key to the diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds daft. It works.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to block a petrol nozzle, and add-on devices are available for cars without one. They are a backstop, not a reason to stop reading the pump.
- As soon as you notice, stop: less petrol inside the tank means a weaker mix. What to do next doesn't change, though — still do not crank it.
Already put petrol in a diesel around Wiswell?
Then, there's just a short order of things. Starting it is out, and so is turning on the ignition. The attendants at the forecourt — whether at Asda itself or wherever you filled up — will normally help push it away from the pump if you ask. What went in, about how much, and if it has run: tell us those when you phone 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Wiswell has a page all for it.
What makes one Wiswell petrol in a diesel task cost more than the next
There's no honest single price for this, since the four situations above are four different jobs. What moves your cost is chiefly which of them you are in. Two things come after that: the petrol that went in as a proportion of what that tank takes, then the spot your car is in and whether our van can get to it safely.
Ahead of any quote, not after, come three questions: your fuel that went in, the amount, and if it's run. That's why. The answers turn a range into a straight figure.
About Wiswell itself
Wiswell is a small village in Lancashire, situated inland at an elevation of 134 metres, with detached housing being the predominant type of accommodation. Wiswell lies approximately 13.8 miles from Preston and 186.5 miles from London, placing it in a relatively rural setting. Wiswell is surrounded by nearby places such as Barrow, Whalley, and Pendleton, and has a population of around 517 residents. Wiswell retains a quiet, residential character, typical of many villages in the North West region.
Across Lancashire and in Wiswell: fuel drain cover
Wiswell sits in the BB postcode area, and our teams that answer petrol in diesel calls there work the locations around it as well — Barrow, Whalley and Pendleton among them. The vehicle doesn't need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Wiswell: still at the pump?
The best place there is, then — that is where you are. Keep it off. Call.