Should You Worry? Petrol in a Diesel Car in Bethania
Likely less than you are now — as long as no one has started the car. Till the ignition primes your pump, the starter cranks, or the car is driven, petrol in a diesel tank simply sits there and does nothing. Which means the truthful reply to that first Bethania question — "have I ruined it?" — normally no. Keep it that way: leave the motor off then phone Petrol in Diesel. What petrol really does to a diesel, how to judge how far it's gone, and how to keep it from happening again: that's the rest 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 ignites, it lubricates — and then it burns. Extremely fine gaps are built into your injectors and the high-pressure pump, and only the diesel flowing through keeps those surfaces from grinding together.
Petrol handles the first task badly and the second not at all. A pump running on a petrol blend is wearing itself out, since petrol is runnier than diesel and strips out the protection the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any clattering comes.
Combined, those make the shape of the issue plain. The harm is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel fault. A pump that has been labouring 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.
Petrol in a diesel in Bethania: how bad is it? Four situations
Filled up, and never started: nothing beats it. Being at a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol held inside the tank alone, it is emptied and rinsed on the spot, and nothing more is needed.
Ignition on, or started for a moment. With your system primed, the fuel lines and filter now contain petrol that came from the tank. Normally little more than emptying, rinsing and sorting your filter, and so still easy.
Some miles driven, and the pump has spent each of them running on weakened fuel. The work is your tank, the lines, your filter and fresh fuel through the whole system, and how hard your car was driven matters as much as how far. A school run to the local primary school is one matter. Any mileage on the Moreton Spur, under 50 miles from Bethania, means your engine has worked hard throughout, and a run to Bangor, under 25 miles away, is a very different job too.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The engine is telling you the fuel is no longer acting like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Pen-y-bryn. What comes first is still the drain and flush-through, and that deals with it, with lasting damage very unusual if a car is pulled over early.
Myths Bethania drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed when you top up — your tank just carries more of the same mixture. That guidance presumes a diesel fuel system tolerates petrol by percentage. It does not.
Not so: a newer diesel copes with a bit of petrol. Rather, the reverse. A modern diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." Any petrol motor fed diesel normally won't run, and so the driver stops and the damage stops with them. Whilst your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running is not 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 separate fault. It does not put back what petrol has diluted, and the petrol is still in that tank afterwards.
"Drain it yourself and you are sorted" — a myth, because after it has been running some petrol lies in your filter and lines, waiting to go straight back through your pump on the next start. Emptying petrol into a can by the roadside is also really risky.
How does petrol in a diesel take place?
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
Routine and your car getting out of step is when it occurs. A vehicle that's new to you — hired, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. The pumps in a different order on a familiar forecourt. A rushed fill en route to Blaenau Ffestiniog with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver accustomed to petrol: precisely when it takes place. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Preventing petrol in a diesel next time you fill up in Bethania
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what matters.
- Inspect the filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in any motor you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, in a home with one of each.
- Before the nozzle comes off the pump the first time you fill a hired or new vehicle, say "diesel" aloud. Silly, yes, but it works.
- While you're thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices exist for the remainder. Count it as a backstop, then keep checking the petrol pump.
- Stop as soon as you realise. Less petrol inside that tank means a thinner mix. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel in Bethania already?
Then, there's only a short order of things. Do not turn your ignition on, and don't crank it. Yet on the forecourt, at the nearest petrol station or anywhere else? Ask the attendants to help you push it clear of the pump. What got in, roughly how much, and whether it's run: tell us that when you call 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a separate issue, with its own page for Bethania, since AdBlue brings corrosion and deposits instead of lost protection.
What makes one Bethania petrol in a diesel job cost more than the next
There's no honest single price for this, because the four situations above are four separate jobs. Which of them you are in is chiefly what moves your cost. After that it's the proportion — how much petrol got in against how much the tank takes — and after that where your car is and whether a van can get to it safely.
That is why our engineers ask three questions before quoting instead of after: what went in, how much, and whether it has run. Those replies are what turn a range into one firm number.
About Bethania and its setting
Bethania is a small suburban area situated on the riverside in Gwynedd, with a mix of terraced housing and a relatively small population of around 1092 residents. Bethania sits at an elevation of 237 metres, near the communities of Maen-Offeren and Blaenau Ffestiniog. Bethania is located approximately 18.5 miles from Bangor and about 190.5 miles from London, in a scenic part of northwest Wales. Bethania's riverside setting provides a distinctive character to the area.
Bethania and Gwynedd: where our fuel drain cover runs
Maen-Offeren, Blaenau Ffestiniog and Manod are among the spots around Bethania that the same teams work, answering petrol in diesel call-outs across Bethania's LL 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 pump in Bethania, still?
No position is better: that is where you now are. Switched off it remains; then phone.