Whitefield: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, worry far less than you probably are. "Have I wrecked it?" is the first thing anyone around Whitefield asks, and the honest answer is generally no, because petrol left in a diesel tank harms nothing until it's drawn through your fuel system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to ring, with the motor kept off, so it remains that way. What petrol really does to a diesel, how to judge how far it has travelled, and how to keep it from happening again: that is the remainder of this page.
What petrol in a diesel does to your engine
Diesel does two tasks on its way through a motor. It protects to begin with, and only then does it burn. What stops the surfaces inside the high-pressure fuel pump and your injectors from wearing down against one another is the diesel flowing through them — they're built to extremely fine clearances.
Of those two tasks, petrol handles the first poorly and the second never. A pump running on a petrol mix is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where the rattling comes.
Seen together, they show the shape the problem has. Contact doesn't do the harm — circulation does. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds goes on, borne by the fuel, into the injectors further along, which is why a pump that has been working on that petrol is where a mechanical problem starts.
Petrol in a diesel around Whitefield: how bad is it? Four cases
Filled but never started — as good as it gets. Just that tank has petrol in it, and so the job is emptying the tank and purging the fuel system where the vehicle sits. This scenario can only really happen on a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a brief start. Once primed, your system has drawn petrol out of your tank up to the fuel filter and your lines. Drain, flush, deal with the fuel filter: still usually straightforward.
Those few miles on the road meant your pump running on fuel thinned by petrol throughout. Tank, lines, filter, then fresh fuel run through the whole system: that's the work, and the way your car was driven matters as much as the distance. Driving the children to Whitefield Infant School and Nursery is one sort of trip. A run as far as Bradford, under 25 miles away, is a very different task. So is any mileage on the M65, under a mile from Whitefield, where your engine has been running hard the whole time.
Rattling, an uneven idle, smoke, a throttle gone soft: driven till it complained. That's the engine telling you its fuel no longer is behaving like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Victoria Street. The drain and flush-through still go first, and they sort it out: if a vehicle is pulled over quickly, permanent damage is very unusual.
Whitefield motorists and that petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed when you top up — the tank simply carries more of the same mixture. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." Lubrication matters more on current diesels, not less, since their fuel runs through more precise parts at higher pressure.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." The driver of a petrol engine fed diesel usually has no choice but to stop, since it will not run, and the harm stops there. A diesel fed petrol normally starts, idles and drives away as though nothing has happened, while the pump wears. Being able to run is not proof of being fine.
An outdated workaround for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive it home." It doesn't put back what petrol has thinned, and that petrol is still in the tank afterwards.
The next start sends petrol back round your pump out of the fuel lines and your filter, where some of that sits once the motor has run. That is why draining your tank yourself doesn't leave you sorted — a myth. And, a can of petrol filled at the kerbside is truly risky.
How petrol ends up: petrol in a diesel
Carelessness is seldom the cause, and no one means to do it. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
Routine and the vehicle falling out of step is how it takes place. Courtesy car, hire car, or a motor that is new. One petrol and one diesel on the drive of the same household. A well-known forecourt with the pumps in a different order. Rushing for a train outside Nelson and filling up en route. A new-to-you diesel Volkswagen Passat, its first fuelling, and a motorist used to petrol: exactly when it takes place. Add a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up in Whitefield: preventing petrol in a diesel
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what counts.
- The first fill in a new motor is the time to check your filler flap — on it, or on the cap, many vehicles state which fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key if a home has one of each. So label it.
- It sounds silly and it works: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- Mistakes like this are simple to make whilst your mind is on something else, so your phone goes away.
- Some diesels have a filler designed to refuse a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- Stop the moment you realise. Less petrol inside your tank makes a weaker mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Whitefield?
The order of things is short, then. Don't turn your ignition on, and do not start it. The attendants on the forecourt — whether at Shell itself or wherever you filled up — will usually help roll it clear of the pump if you ask. What was put in, about how much, and if it's run: tell us that when you ring 0333 366 0103.
Corrosion and deposits are the problem with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Whitefield page.
Whitefield petrol in a diesel jobs: why one costs more than another
The four scenarios above are four separate tasks, so no single quote for this would be honest. What shifts your cost is chiefly which of them you're in. After that it is the share — how much petrol got in against how much your tank takes — and after that where the car is and whether a van can reach it safely.
Ahead of any quote, not after, come three questions: your fuel that was put in, the quantity, and whether it's run. That's why. The replies turn a range into a straight figure.
About Whitefield itself
Whitefield is a suburban area in Lancashire, situated near the lakeside and surrounded by nearby places such as Lomeshaye, Nelson, and Carr Hall. Whitefield has a population of approximately 9930 residents and is characterised by predominantly terraced housing. Whitefield sits at an elevation of 134 metres, providing a relatively flat landscape. Whitefield is located 19.3 miles from Bradford and 183.2 miles from London.
Whitefield and Lancashire: where our fuel drain cover runs
Whitefield waits in the BB postcode area, and the vans that answer petrol in diesel call-outs there work the spots near it as well — Lomeshaye, Nelson and Carr Hall among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our technicians drain, and your vehicle does not need to move to us.
At the pump around Whitefield, right now?
Nothing beats it: that is where you are. Ring, and keep it turned off.