Petrol in a Diesel Car in Tudhoe: How Worried Should You Be?
Less than you probably are, provided it has not been started. Until your ignition primes your pump, the starter turns, or your car is driven, petrol in a diesel tank just rests there and does no harm. Which means the truthful reply to the first Tudhoe question — "have I ruined it?" — usually no. Petrol in Diesel is who to ring, with your engine left off, so it stays that way. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening a second time: that's the rest of this page.
Inside the motor: what petrol in a diesel does
Diesel does two tasks on its way through a motor. It burns, and before it combusts it protects. What keeps the surfaces inside the high-pressure fuel pump and the injectors from grinding against one another is your diesel passing through them — they are designed to extremely fine tolerances.
Of these two tasks, petrol manages the first poorly and the second never. The knocking comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system hinges on, and any pump working on such a mixture is wearing itself.
Put those together and the shape of the trouble is clear. Not contact but movement is what does the harm. Petrol in a tank is a fuel problem. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
How bad is petrol in a diesel? Four scenarios we see in Tudhoe
Fuelled but not once started — as good as it gets. Being at a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol kept inside your tank alone, it is emptied and flushed on the spot, and nothing more is needed.
Started for a second, or just the ignition on. Once primed, the fuel system has pulled petrol out of the tank as far as the filter and the fuel lines. That is generally still a straightforward task — a drain, a flush, and the filter dealt with.
Your pump now spent a few miles on diluted fuel — that's what driving the car does. Distance is only half of that; how hard it was driven matters equally. Either way this work runs to your tank, the lines, your filter and clean fuel through the entire system. The school run to St Charles' Catholic Primary School, Tudhoe is one thing. A run as far as Durham, under 5 miles away, is a very different job. So is any miles on the A1(M), under 3 miles from Tudhoe, where the engine has been running hard throughout.
Driven on until it complained — clattering, smoke, a ragged idle, a soft throttle. What you are hearing is your motor signalling fuel that no longer behaves like diesel. Pull up where you are — on the verge on Saint Charles Road, at the kerb, down a side road — and do not move it again. The fuel drain and flush still go first, and they deal with it: if a vehicle is pulled over quickly, permanent damage is very rare.
What Tudhoe drivers get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — the tank just carries more of the same blend. A diesel fuel system does not accept petrol by percentage in the way that advice assumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Smaller components and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more motorists than any other. Diesel in a petrol motor normally means a motor that won't run: the motorist stops, and so does the harm. Feed petrol to a diesel and it normally fires up, idles and drives away like nothing has happened — all the while its pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive the car home." It's an old workaround for a separate issue. That petrol is still in the tank after that, and what it has weakened isn't put back.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol lies in the fuel filter and lines, waiting to go straight back through the pump on the next start. On top of that, petrol cleared into a can by the road is truly risky.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol car at all. So the mistake runs one way.
It takes place when routine and the car stop matching. Courtesy car, hire car, or a vehicle that is new. Two vehicles on one drive, one petrol, one diesel. Your ordinary forecourt, its pumps now in a different order. A train to catch, and a rushed fill on the way to Durham. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is precisely the moment it occurs. 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 Tudhoe
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- Check your filler flap. Plenty of vehicles state the fuel type inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key if a house has one of each. So label it.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It sounds daft and it works.
- While you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Less petrol makes a thinner mixture, and so stop as soon as you realise — while remembering that your next stage is unchanged. It's still not to fire it up.
Petrol already in a diesel in Tudhoe? Start here
Then, there's just a short order of things. Never start the vehicle, and do not turn your ignition on. The staff at the forecourt — whether at Asda itself or wherever you filled up — will normally help roll it away from the petrol pump if you ask. Call 0333 366 0103 next, with three facts — the fuel, the rough amount, and if it's run.
Say so if it was AdBlue instead of petrol: it is a separate fault, with its own page for Tudhoe, because AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel job around Tudhoe costs more than another
The four situations above are four different jobs, so no single quote for this would be honest. What moves the cost is chiefly which of them you are in. The ratio counts next, meaning how much of your tank is petrol, followed by the position of your car and whether reaching it is safe for a technician.
That is why our engineers ask three questions before quoting instead of after: what went in, how much, and whether it has run. Their answers are what turn a range into one firm number.
About Tudhoe, for a moment
Tudhoe is a suburban area located inland in County Durham, approximately 4.6 miles from the city of Durham. Tudhoe sits at an elevation of around 100 metres, forming part of the wider residential area surrounding Durham. Tudhoe is characterized by its semi-detached housing and proximity to nearby places such as Tudhoe Village and Tudhoe Grange. Tudhoe is situated in the North East region of England, about 229.6 miles from London.
Tudhoe and Durham: where our fuel drain cover reaches
Tudhoe rests in the DL postcode area, and our teams that answer petrol in diesel calls there work the spots around it as well — Tudhoe Village, Tudhoe Grange and Mount Pleasant among them. We drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the petrol pump in Tudhoe, still?
Nothing beats it: that is where you now are. Call, and leave it turned off.