Broughton: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, you can worry less than you likely are. "Have I wrecked it?" is the first question anyone around Broughton asks, and the honest answer is normally no, since petrol left in a diesel tank hurts nothing till it is drawn through the system — by ignition priming, by the starter, or by being driven. Leave your motor off and call Petrol in Diesel — that is how you keep it like that. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and the way to make sure you don't repeat it.
What petrol in a diesel does to the engine
On its way through an engine, diesel has two jobs. Lubricating comes before burning; it does both. What stops the surfaces inside your high-pressure pump and the injectors from wearing against each other is the diesel passing through them — they are built to very fine clearances.
Petrol handles the first job badly and the second not at all. A pump running on a petrol mix is wearing itself out, because petrol is thinner than diesel and strips out the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where any rattling comes.
Seen together, they make clear the shape the problem has. Not contact but movement is what causes the damage. Petrol in a tank is a fuel fault. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors beyond it.
Four situations we see around Broughton: how bad is petrol in a diesel?
Fuelled but not once started — the best it gets. That petrol is inside your tank and just that tank, and the task is a drain and a flush where your car stands. This is the one situation that can only truly occur on a forecourt, as anywhere else the vehicle has been driven to get there.
A moment's running, or just the ignition on. The system has been primed, so petrol has left that tank and got to the fuel filter and the fuel lines. Drain, flush, deal with your filter: still normally simple.
Those few miles on the road were the pump labouring on fuel thinned by petrol the whole way. How hard the car was driven matters as much as how far, and this work covers that tank, the lines, the filter and clean fuel through the whole circuit. The school run to the local primary school is one matter. Driving as far as Edinburgh, under a mile away, makes a very different job — as does any mileage on the M8, under 10 miles from Broughton, with the motor running hard all the way.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. That's your motor telling you its fuel has stopped behaving like diesel. Stop wherever you are — the verge on East Claremont Street, a lay-by, a side street — then leave it there. What comes first is still the fuel drain and flush-through, and that sorts it out, with long-term damage very rare when a vehicle is pulled over early.
Petrol in a diesel myths Broughton people hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing comes out when you top up — that tank simply holds more of the same blend. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through finer parts: that is how a current diesel handles its fuel, and so the protection matters for more, not less.
This is the one that catches people. Myth: "If it starts and drives, there is no damage done." The driver of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the harm stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Being able to run is not the same as being fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another issue. None of what petrol thinned gets put back by it — and later, the tank still holds the petrol.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in your filter and lines, waiting to go straight back through the pump at your next start. It's also really risky to drain petrol into a can at the kerbside.
Why petrol in a diesel happens so easily
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle mostly won't go into a petrol vehicle, but the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake straightforward, and only in that direction.
It happens when routine and your car stop matching. Any motor that is new to you — a hire car, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A hurried fill en route to Edinburgh Waverley with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Tiguan in front of you on the forecourt for its first tank — that's when. Throw in a back seat full of children, a phone call or rain, and the hand wins.
Avoiding petrol in a diesel next time you fill up around Broughton
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of cars state the fuel inside your filler flap or on the cap, so check there on your first fill in any vehicle you don't know.
- One of each in the household? Mark your key to the diesel — a coloured fob, a sticker — since meaning to remember isn't enough.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- While you are thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Some diesels come with a filler built to reject a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- Stop as soon as you notice. Less petrol in that tank means a thinner mix. It doesn't change what to do next, which is still not to fire it up.
Broughton: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off too. Yet on the forecourt, at BP or anywhere else? Ask the staff to help you push it clear of the petrol pump. What got in, about how much, and if it has run: tell us those when you ring 0333 366 0103.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Broughton page.
What makes one Broughton petrol in a diesel job cost more than the next
There's no fair single price for this, since the four situations above are four separate tasks. What moves the cost is mostly which of them you are in. Where the vehicle is matters too, and whether a van can safely get to it, after the share of petrol to what that tank takes.
Ahead of any quote, not after, we ask three queries: your fuel that was put in, its volume, and if it has run. That's why. A range becomes a straight figure once the replies are in.
About Broughton itself
Broughton is a suburban area in the City of Edinburgh, situated near the coast and approximately 0.7 miles from Edinburgh city centre. Broughton sits at an elevation of 34 metres, with its predominant housing being flats. Broughton is close to nearby places such as Canonmills, Pilrig, and Bonnington, and is home to a population of around 14894 people.
Across City of Edinburgh and around Broughton: fuel drain cover
Petrol in diesel call-outs around Broughton — part of the EH postcode area — go to teams that also cover the locations round it, Canonmills, Pilrig and Bonnington among them. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
Still at the petrol pump around Broughton?
The best spot there is, then — that is where you are. Leave the car switched off, then ring.