Should You Worry? Petrol in a Diesel Car in Shallowford
Provided it has not been started, you can worry far less than you probably are. Till your ignition primes the pump, the starter turns, or your car is driven, petrol in a diesel tank just waits there and does nothing. Which means the truthful reply to the first Shallowford question — "have I ruined it?" — normally no. Leave your motor off and call Petrol in Diesel — that keeps it like that. What petrol actually does to a diesel, how to judge how far it has gone, and how to keep it from happening a second time: that's the rest of this page.
Inside the engine: what petrol in a diesel really does
On its way through an engine, diesel does two jobs. It lubricates first, and after that does it burn. Made to extremely fine tolerances, the injectors and the pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
The second task petrol doesn't do at all, and the first it does badly. It's runnier than diesel and takes away the protection the system depends 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 knocking comes from.
Put these together and the shape of the trouble is plain. It's circulation that does the harm, not contact. Petrol in the tank is a fuel issue. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors further on.
Shallowford, petrol in a diesel: four cases, from mild to serious
Fuelled, and never started: no case is better. Being on a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol kept in the tank alone, it is cleared and purged on the spot, and nothing more is needed.
Started for a second, or only the ignition on. Petrol has left that tank and got to the fuel filter and your lines, because the system has been primed. Usually little more than draining, purging and sorting your filter, so still simple.
Those few miles driven meant the pump working on fuel diluted by petrol throughout. How hard your car was driven matters as much as how far, and the work covers that tank, the fuel lines, your filter and clean fuel through the whole circuit. Short trips, like the school run to Springfields First School, are one matter. A run as far as Stoke-on-Trent, under 15 miles away, is a very different task. So is any mileage on the M6, under 3 miles from Shallowford, where the motor has been running hard the whole time.
Driven on until it complained — clattering, smoke, an uneven idle, a dead throttle. That is the motor telling you its fuel has stopped behaving like diesel. Whether it's the verge on Worston Lane, a lay-by or a side road, stop there and leave it. The drain and flush still come first, and they take care of it: if a vehicle is stopped quickly, permanent damage is very rare.
What Shallowford motorists get told about petrol in a diesel — and the stories in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you're left with a bigger tank, still the same mix. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. More precise components and higher pressure are how a newer diesel runs its fuel, and that makes the protection count more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. The driver of a petrol motor fed diesel normally stops, because it will not run, and the damage stops there. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, whilst the pump wears. Running isn't the same as fine.
An outdated fix for a separate fault lies behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has thinned stays diluted, and that petrol remains inside your tank anyway.
Once the engine has run, part of the petrol sits in the filter and the lines, not your tank — and your next start sends it straight back through your pump. So the myth "drain that tank yourself and you're sorted" does not hold. On top of that, petrol emptied into a can by the road is truly dangerous.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and nobody does it on purpose. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol vehicle. That's how the forecourt makes it straightforward.
The moment routine stops matching your car is the moment it happens. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill on the way to Norton Bridge. A new-to-you diesel Skoda Octavia, its first fuelling, and a driver used to petrol: exactly when it takes place. Throw in a back seat full of children, a phone call or rain, and the hand takes over.
Avoiding petrol in a diesel next time you fill up in Shallowford
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Check the petrol pump's label; the colour is just a hint.
- In a motor you don't know, look inside the flap over the filler or at the cap before the first fill: many cars state the fuel type there.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key when a home 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 silly. It does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels have a filler designed to reject a petrol nozzle, and devices you can add exist for motors 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 the tank means a weaker blend. It doesn't change what to do next, which is still not to crank it.
Already put petrol in a diesel around Shallowford?
Then the order of things is short. Starting it is out, and so is turning on your ignition. The attendants on the forecourt — whether at Esso itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it's been run.
Say so if it was AdBlue rather than petrol: it is a separate issue, with its own page for Shallowford, since AdBlue brings corrosion and deposits instead of lost lubrication.
One petrol in a diesel job in Shallowford costs more than another. Why?
Four separate tasks sit behind the four scenarios above — which is why there is no fair single price. What shifts the cost is mostly which of them you are in. Beyond that it's the share — how much petrol got in against how much the tank takes — and then where the vehicle is and whether a van can get to it safely.
Three questions come first, before any quote, instead of after — what went in, how much, has it run — and this is the reason. Their replies are what turn a range into one firm number.
About Shallowford
Shallowford is a small hamlet in Staffordshire, situated on the riverside at an elevation of 87 metres, with detached housing being the predominant type of accommodation. Shallowford lies near the villages of Little Bridgeford, Chebsey, and Norton Bridge, and is approximately 11 miles from Stoke-on-Trent. Shallowford has a population of around 563 people and is located in a rural area of the West Midlands region. Shallowford is also relatively distant from London, at a distance of around 128 miles.
Shallowford and Staffordshire: where our fuel drain cover runs
Little Bridgeford, Chebsey and Norton Bridge are among the places around Shallowford that the same teams work, answering petrol in diesel jobs across Shallowford's ST postcode area. We drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Shallowford and still at the petrol pump?
In that case, you could not be in a better spot. Switched off it stays; then call.