How Worried Should You Be? Petrol in a Diesel Car in Heath Cross
Likely less than you already are — provided no one has started the car. Everyone in Heath Cross begins with "have I wrecked it?", and the honest answer is normally no: petrol resting inside the tank of any diesel stays harmless till priming, cranking or driving pulls it into the system. Keep it that way: leave the motor off and phone Petrol in Diesel. Below, this page sets out what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to your engine?
On its way through an engine, diesel does two jobs. It combusts, and before it ignites it protects. What stops the surfaces inside the high-pressure pump and the injectors from wearing against each other is your diesel passing through them — they're made to very fine clearances.
The second job petrol does not do at all, and the first it does badly. The rattling comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection your system hinges on, and any pump running on that mixture is wearing itself.
Taken together, they make clear the shape the trouble has. Not contact but circulation is what causes the harm. A tank with petrol in it is a fuel fault. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Petrol in a diesel in Heath Cross: how serious is it? Four situations
The best case there is: filled up, not once started. Just your tank has petrol in it, so the task is clearing your tank and cleaning your system where your car stands. This situation can only really happen on a forecourt: anywhere else, the car got there by being driven.
The ignition switched on, or a brief start. With the system primed, the lines and filter now contain petrol that came from your tank. Drain, flush, see to the filter: still usually straightforward.
A couple of miles driven, and the pump has spent each of them working on thinned fuel. Tank, lines, filter, then clean fuel run through the entire system: that's this work, and the way the vehicle was driven matters as much as the miles. Short trips, such as the school run to Spreyton School, are one thing. Very different a second time: a trip to Exeter, under 15 miles away, or any distance on the M5, under 15 miles from Heath Cross, where your engine kept labouring hard.
Driven till it complained. Clattering, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is your motor reporting fuel that no longer runs like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Northbeer Lane. What comes first is still the drain and flush-through, and that deals with it, with permanent damage very uncommon when a vehicle is pulled over early.
What Heath Cross people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. The assumption behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. A newer diesel runs its fuel through finer parts at higher pressure, which makes the protection count more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. Any petrol motor fed diesel generally won't run, so the driver stops and the damage stops with them. While the pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Being able to run isn't proof of being fine.
An old workaround for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still inside that tank after that, and whatever it has weakened isn't put back.
Once the motor has been run, part of that petrol is in your filter and the fuel lines, not your tank — and your next start sends it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not hold. And, a can of petrol filled by the roadside is genuinely risky.
Why petrol in a diesel occurs at all
A careless moment is seldom the cause, and nobody means to do it. 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 simple, and the mistake runs one way.
The moment habit stops matching your car is the moment it occurs. Courtesy car, hire car, or a car that is brand new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps arranged differently. A rushed fill en route to Yeoford with a train to catch. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Throw in rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up around Heath Cross
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the pump's label; the colour is only a hint.
- Plenty of motors state the fuel inside your filler flap or on the cap, and so check there on the first fill in any car you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So label it.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It sounds daft. It works.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices are available for cars without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Less petrol means a weaker mixture, and so stop as soon as you notice — though remembering that the next stage is unchanged. It's still not to start the vehicle.
Heath Cross: already put petrol in a diesel?
Then, there is just a short order of things. Don't turn your ignition on, and don't start it. The staff on the forecourt — whether at Esso itself or wherever you filled up — will usually help roll it away from the pump if you ask. Next, 0333 366 0103. We'll ask what went in, about how much, and if it has been run.
If it was AdBlue rather than petrol, say so. That's a separate issue — corrosion and deposits rather than lost lubrication — and it has its own page for Heath Cross.
One petrol in a diesel job in Heath Cross costs more than another. Why?
The four situations above are four different tasks, so no single price for this would be fair. Which of them you're in is chiefly what moves the cost. Where your car is counts too, and whether a technician can safely get to it, after the ratio of petrol to what that tank holds.
Before any quote, not after, come three queries: your fuel that went in, the quantity, and whether it has run. That's why. A range becomes a straight figure once the replies are in.
About Heath Cross and where it is
Heath Cross is a small locality in inland Devon, situated approximately 191 metres above sea level. Heath Cross lies near several nearby villages, including Spreyton, Hillerton, and Itton, and is about 13.6 miles from the city of Exeter. Heath Cross has a population of around 520 people and is characterised by predominantly detached housing.
Heath Cross and Devon: where our fuel drain cover reaches
Petrol in diesel call-outs around Heath Cross — part of the EX postcode area — go to teams that also cover the places around it, Spreyton, Hillerton and Itton among them. Our technicians drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Heath Cross and still at the pump?
Then you're in the best position there is. Keep it off. Ring.