Somerton: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — provided no one has started the vehicle. Petrol resting in a diesel tank does nothing to your motor till something pulls it through the fuel system — the ignition priming the pump, your starter, or driving on its own. So the honest answer to the first question everyone around Somerton asks, "have I ruined it?", is generally no. Keep it that way: leave the motor off and ring Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has spread, and ways to make sure you never repeat it.
Petrol in a diesel: what does it do to the engine?
Diesel does two jobs on its way through an engine. It ignites, and before it burns it lubricates. Built to extremely fine clearances, the fuel injectors and the pump depend on the diesel moving through them to keep their surfaces from wearing against one another.
Badly at the first, not at all at the second: that is petrol. It's thinner than diesel and strips away the protection your fuel 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 clattering comes from.
Put these together and the shape of the trouble is clear. It's movement that causes the harm, not contact. Petrol in the tank is a fuel problem. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Petrol in a diesel around Somerton: how bad is it? Four cases
Fuelled, and never started: no case is better. On a forecourt, and really only there, the petrol is still confined to the tank — since anywhere else the vehicle was driven to get to it. The task is emptying and rinsing on the spot.
The ignition switched on, or a short start. Once primed, your system has pulled petrol from the tank as far as the fuel filter and the lines. Usually little more than emptying, purging and sorting the filter, so still straightforward.
Driven a few miles. Now your pump has spent these miles running on diluted fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's the work, and the way the car was driven counts as much as the mileage. Driving the children to the local primary school is one sort of trip. A run as far as Newport, under 3 miles away, is a very different job. So is any miles on the M4, under a mile from Somerton, where the engine has been working hard throughout.
Driven until it complained. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer acting like diesel. Stop where you are — on the verge on Somerton Road, at the kerb, down a side road — and do not move it. What comes first is still the drain and flush-through, and that sorts it out, with long-term damage very unusual when a vehicle is stopped early.
Myths Somerton motorists hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a bigger tank of the same mixture. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Not so: a current diesel copes with a bit of petrol. If anything, the reverse. More precise parts and higher pressure are how a current diesel runs its fuel, and that makes the lubrication count more, not less.
The myth that catches drivers out: if it starts and drives, it must be unharmed. A petrol motor fed diesel normally will not run, so the driver stops and the damage stops with them. A diesel fed petrol generally starts, idles and drives away as though nothing has happened, whilst the pump wears. Fine and running are not the same at all.
An old workaround for a distinct problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." None of what petrol weakened gets put back by it — and later, your tank still contains the petrol.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol sits in the filter and lines, waiting to go right back through your pump at your next start. Emptying petrol into a can by the kerbside is also really dangerous.
How it happens: petrol in a diesel
Carelessness is rarely the cause, and nobody means to do it. A diesel nozzle mostly won't fit a petrol vehicle, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error straightforward, and only in one direction.
It happens when routine and the vehicle stop matching. A motor that is new to you — hired, on loan as a courtesy car, or brand new. One petrol and one diesel on the drive of the same household. Your normal forecourt, its pumps suddenly in a different order. A hurried fill on the way to Newport (South Wales) with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: exactly when it happens. Add rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Somerton people: how to avoid petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what matters.
- Plenty of cars state the fuel type inside the filler flap or on the cap, so check there on your first fill in any vehicle you don't know.
- Good intentions do less than a sticker or a fob in a vivid 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 gets its first tank. It seems daft. It works.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to refuse a petrol nozzle, and add-on devices exist for motors without one. They are a backstop, not a reason to stop checking the petrol pump.
- Noticing it mid-fill? Stop at once. A weaker blend results from less petrol in your tank, yet your next stage remains the same: don't fire it up.
Petrol already in a diesel around Somerton? Start here
Then the order of things is brief. Don't switch the ignition on, and do not crank it. The attendants at the forecourt — whether at Esso itself or wherever you filled up — will normally help roll it away from the pump if you ask. Call 0333 366 0103 next, with three answers — your fuel, the approximate amount, and if it has run.
If it was AdBlue rather than petrol, say so. That is a separate problem — corrosion and deposits instead of lost protection — and it has its own page for Somerton.
One petrol in a diesel job around Somerton costs more than another. Why?
There's no honest single quote for this, since the four scenarios above are four separate jobs. Which of them you are in is chiefly what moves your cost. Two things come after that: the petrol that went in as a proportion of what your tank takes, then the place the car is in and whether a technician can reach it safely.
What went in, how much, and if it's run — three questions our technicians ask before costing, not after, for precisely that reason. Their answers are what change a range into one firm number.
About Somerton itself
Somerton is a suburban area located on the coast of Wales, near the city of Newport, with a mix of terraced housing and other residential properties. Somerton sits at a low elevation of around 9 metres, close to the nearby communities of Liswerry, Alway, and Beechwood. Somerton is situated approximately 1.5 miles from Newport, making it a convenient residential location. Somerton has a population of around 9028 people, according to recent estimates.
Fuel drain cover in Somerton and across Newport
Liswerry, Alway and Beechwood are among the spots around Somerton that the same teams work, answering petrol in diesel calls across Somerton's NP postcode area. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
In Somerton and still at the pump?
Then, you could not be in a better position. Leave the vehicle switched off, then ring.