Petrol in a Diesel Car in Buckley: How Worried Should You Be?
Not started? Then less anxious than you probably feel. Until your ignition primes the pump, the starter turns, or the car is driven, petrol in a diesel tank simply rests there and does no harm. Which makes the honest reply to the first Buckley question — "have I ruined it?" — normally no. Leave the engine off then call Petrol in Diesel — that keeps it like that. Further down, 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.
Inside the engine: what petrol in a diesel really does
Two tasks fall to diesel on its route through a motor. Before it combusts, it protects — then it combusts. Built to very fine clearances, the injectors and your pump depend on the diesel flowing through them to keep their surfaces from wearing against one another.
Of those two tasks, petrol manages the first badly and the second not at all. It is thinner than diesel and removes the protection the system hinges on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the clattering comes from.
Put those together and the shape of the issue is clear. It is movement that does the harm, not contact. Petrol in the tank is a fuel problem. Whatever a worn pump sheds goes on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical fault begins.
Four situations we see around Buckley: how bad is petrol in a diesel?
Filled up, and never started: no case is better. On a forecourt, and really only there, the petrol is still limited to your tank — since everywhere else the car was driven to get to it. The job is draining and flushing on the spot.
Started for a second, or just your ignition on. Petrol has come out of that tank and reached the filter and the fuel lines, since your system has been bled. Still generally simple: drain, flush, and the fuel filter sorted.
A few miles driven, and the pump has spent every one of them working on weakened fuel. How hard the car was driven matters as much as how far, and this work takes in the tank, the lines, the filter and clean fuel through the whole system. On the school run to the local primary school, the distance is small. Getting as far as Chester, under 10 miles away, makes a very different job — as does any mileage on the M56, under 10 miles from Buckley, with the motor labouring hard the whole time.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and your engine is telling you. Pull up wherever you are — the verge on Brunswick Road, a lay-by, a side street — and leave the vehicle there. A car pulled over early very seldom has long-term damage, because the fuel drain and the flush-through, which still come first, deal with it.
What Buckley people get told about petrol in a diesel — and the myths in it
False: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all you get, since topping up takes out nothing. That guidance supposes a diesel fuel system handles petrol by percentage. It does not.
Myth: a newer diesel copes with a bit of petrol. If anything, the opposite. Protection matters more on current diesels, not less, since their fuel runs through more precise parts at higher pressure.
Myth: "If it starts and drives, there's no harm done." This is the one that catches people. Any petrol motor fed diesel generally will not run, and so the driver stops and the harm stops with them. Feed petrol to a diesel and it generally starts, ticks over and drives away as if nothing has happened — all while its pump wears. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different issue. What petrol has weakened stays diluted, and the petrol stays inside that tank regardless.
Once the motor has been run, part of the petrol is in the fuel filter and your lines, not that tank — and the next start pulls it straight back through the pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Also, a can of petrol filled at the kerbside is truly hazardous.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it easy.
Habit and the car falling out of step is how it takes place. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps laid out differently. Racing for a train outside the nearest station and fuelling up en route. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. With rain, a call coming in, or a car full of children to deal with, the hand just does what it always has.
Next time you fill up in Buckley: preventing petrol in a diesel
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles state the fuel type there.
- Mark the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- "Diesel", out loud, before you pick up the nozzle — each time a new or hired car needs its first tank. It sounds daft. It does the trick.
- Mistakes like this are easy to make whilst your mind is on something else, and so the phone goes away.
- Add-on devices exist for motors without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside your tank makes a thinner blend. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel in Buckley?
In that case, there is just a short order of things. Don't switch the ignition on, and don't fire it up. If you are still on the forecourt — BP or anywhere else — ask the attendants to help you push the vehicle away from the pump. Ring 0333 366 0103 next, with three answers — your fuel, the rough volume, and if it's run.
If it was AdBlue and not petrol, say so. That is a separate issue — corrosion and deposits instead of lost lubrication — and it has its own page for Buckley.
What makes one Buckley petrol in a diesel task cost more than the next
A fair single quote does not exist here: four situations, four separate tasks. What moves the cost is chiefly which of them you're in. Two things come after that: the petrol that was put in as a proportion of what the tank takes, then the place your car is in and whether a van can get to it safely.
That is why we ask three queries before costing rather than after: what got in, how much, and if it's run. Those replies are what turn a range into one firm number.
About Buckley itself
Buckley is a town in Flintshire, situated inland in northeast Wales, approximately 8 miles from Chester. Buckley sits at an elevation of 157 metres, overlooking the surrounding countryside. Buckley has a mix of housing types, but semi-detached homes are predominant, and the town is close to nearby places such as Coppa View and Nant Mawr. Buckley is also home to Buckley Mountain, a notable local landmark.
Across Flintshire and around Buckley: fuel drain cover
Buckley waits in the CH postcode area, and the teams that answer petrol in diesel call-outs there work the spots near it as well — Coppa View, Nant Mawr and Buckley Mountain among them. Our technicians drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the pump around Buckley?
The best place there is, then — that is where you are. Keep the car turned off, and ring.