Petrol in a Diesel Car in Blaguegate: How Worried Should You Be?
Far less than you likely are, provided it hasn't been started. "Have I wrecked it?" is the first thing anyone around Blaguegate asks, and the truthful answer is generally no, because petrol resting in a diesel tank hurts nothing till it's drawn through the fuel system — by ignition priming, by the starter, or by driving. Leave your motor off then ring Petrol in Diesel — that keeps it that way. What petrol really does to a diesel, how to judge how far it has travelled, and how to keep it from happening again: that's the rest of this page.
What petrol in a diesel does to the motor
Diesel has two tasks on its way through a motor. It lubricates to begin with, and after that does it burn. What keeps the surfaces inside your high-pressure pump and the injectors from wearing down against one another is your diesel passing through them — they are made to very fine gaps.
Petrol handles the first job badly and the second not at all. A pump working on a petrol blend is wearing itself out, since petrol is runnier than diesel and strips out the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that is where any knocking comes.
Put these together and the shape of the problem is plain. It's movement that does the damage, not contact. All a tank with petrol in it amounts to is a fuel problem. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to your injectors further on.
Blaguegate, petrol in a diesel: four cases, from mild to major
The best case there is: filled up, never started. On a forecourt, and really only there, the petrol is still limited to your tank — because everywhere else the car was driven to reach it. The task is emptying and rinsing on the spot.
Started for a moment, or just the ignition on. Once primed, the system has drawn petrol from that tank up to the fuel filter and the lines. Drain, flush, see to your filter: still normally easy.
Your pump has spent a couple of miles on thinned fuel — that's what driving the car meant. The work is the tank, the lines, the filter and clean fuel through the whole circuit, and how hard your car was driven matters as much as how far. The school run to St Richard's Catholic Primary School, Skelmersdale is one matter. Any miles on the M58, under a mile from Blaguegate, means the engine working hard throughout, and a run to Liverpool, under 15 miles away, is a very different job too.
Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. That is the motor telling you its fuel has stopped acting like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Dicket's Lane. A car stopped soon very rarely has permanent damage, since the drain and the flush, which still come first, deal with it.
Blaguegate people and that petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice assumes.
Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through finer parts: that's how a current diesel moves its fuel, so the lubrication matters for more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. The driver of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops with them. While your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. None of what petrol thinned gets put back by it — and afterwards, the tank still contains the petrol.
If the motor has run, part of the petrol sits in the fuel filter and the fuel lines, not the tank — and your next start sends it right back through your pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Emptying petrol into a can at the roadside is also really hazardous.
How it happens: petrol in a diesel
No one does it on purpose, and it's seldom carelessness. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol vehicle at all. The forecourt makes it easy, and the error runs one way.
It happens when routine and the car stop matching. A new motor, a hire car or a courtesy car. Households running one of each, petrol and diesel. Your ordinary forecourt, its pumps now in a different order. Rushing for a train outside Ormskirk and filling up en route. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up around Blaguegate: avoiding petrol in a diesel
- Read the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what matters.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of cars state the fuel type there.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, for a home with one of each.
- It seems silly and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a safety net, and keep reading the petrol pump.
- Less petrol makes a weaker blend, so stop as soon as you realise — while remembering that your next stage is unchanged. It is still not to fire it up.
Put petrol in a diesel in Blaguegate already?
Then, there is only a short order of things. Do not turn the ignition on, and don't start it. Yet at the forecourt, at BP or anywhere else? Ask the staff to help you roll the vehicle away from the petrol pump. Then phone 0333 366 0103 and tell us what was put in, about how much, and whether it has run.
If it was AdBlue instead of petrol, say so. That is a separate problem — corrosion and deposits instead of lost lubrication — and it has its own page for Blaguegate.
One petrol in a diesel job in Blaguegate costs more than another. Why?
The four situations above are four different jobs, so no single price for this would be honest. What moves the cost is chiefly which of them you are in. After that it's the share — how much petrol went in against how much your tank takes — and then where the car is and whether a van can get to it safely.
What got in, how much, and whether it's run — three queries our engineers ask before quoting, not after, for exactly that reason. The replies turn a range into a straight figure.
About Blaguegate itself
Blaguegate is a village in Lancashire, situated on the riverside at an elevation of 66 metres, with semi-detached housing being the predominant type of accommodation. Blaguegate lies near several smaller settlements, including Brighouse Green and West Gillibrands, and is close to the larger urban area of Liverpool. Blaguegate is located in the North West region of England, approximately 181 miles from London. Blaguegate has a population of around 645 residents.
Blaguegate and Lancashire: where our fuel drain cover runs
Blaguegate sits in the WN postcode area, and our teams that answer petrol in diesel call-outs there work the locations near it as well — Brighouse Green, West Gillibrands and Four Lane Ends among them. We drain wherever the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the petrol pump in Blaguegate?
No position is better: that's where you now are. Keep it off. Ring.