How Worried Should You Be? Petrol in a Diesel Car in Penketh
Far less than you likely are, provided it has not been started. "Have I wrecked it?" is the first question anyone in Penketh asks, and the honest answer is usually no, since petrol resting in a diesel tank harms nothing until it's drawn through the fuel system — by ignition priming, by your starter, or by being driven. Keep it like that: leave your motor off and call Petrol in Diesel. The remainder of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
Inside the engine: what petrol in a diesel really does
Diesel has two tasks on its way through a motor. It protects first, and only then does it burn. Extremely fine tolerances are built into the injectors and your high-pressure pump, and just your diesel running through stops those surfaces grinding together.
Petrol does the first task badly and the second not at all. The clattering comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection your system rests on, and any pump working on that mix is wearing itself.
Combined, those leave the shape of the issue plain. Contact doesn't do the damage — movement does. Where that petrol is only in your tank, it's an issue of fuel, nothing more. Once the pump has been working on that petrol, a mechanical issue has started: anything shed by a pump that is wearing down is carried onward to the injectors with your fuel.
Penketh, petrol in a diesel: four situations, from mild to major
Filled up, never started. The best case there can be. That petrol is in that tank and only the tank, and the job is a drain and a flush where the vehicle sits. This is the one situation that can only really occur at a forecourt, because anywhere else your car has been driven to get there.
Ignition on, or started for a second. Once primed, the fuel system has drawn petrol out of your tank as far as the fuel filter and the lines. Drain, flush, deal with your filter: still normally easy.
Those few miles driven meant your pump working on fuel diluted by petrol throughout. Mileage is only half of it; how hard it was driven counts just as much. Either way this work runs to the tank, the lines, the filter and fresh fuel through the whole circuit. Driving the children to St Vincent's Catholic Primary School is one sort of trip. Driving as far as Liverpool, under 15 miles away, makes a very different job — as does any mileage on the M62, under 3 miles from Penketh, with the motor running hard all the way.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you your fuel is no longer acting like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Warrington Road. Long-term damage is very rare when a car is stopped quickly, and the fuel drain and flush-through that still go first sort it out.
Stories Penketh motorists hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you are left with a bigger tank, still the same mix. Percentage isn't how a diesel fuel system tolerates petrol, however much that advice supposes.
Not so: a current diesel copes with a bit of petrol. If anything, the opposite. At higher pressure, through more precise components: that's how a current diesel handles its fuel, and so the lubrication matters for more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up most people than any other. Feed diesel to a petrol motor and it normally won't run, and so the motorist stops — and the harm stops with them. Whilst your pump wears, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Running is not the same as fine.
An outdated fix for a separate issue lies behind this one. Myth: "Add some two-stroke oil and drive it home." It does not put back what petrol has weakened, and the petrol is still in that tank later.
Myth: "Drain that tank yourself and you are sorted." After your engine has been run, some of the petrol is no longer inside your tank: it's in the fuel filter and the fuel lines, and it goes right back through the pump on your next start. On top of that, petrol drained into a can by the road is truly dangerous.
Why petrol in a diesel occurs at all
Nobody does it on purpose, and it's rarely carelessness. The petrol nozzle is the smaller of the two and slides 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 error runs one way.
It takes place when habit and your car stop matching. Any car that's new to you — a hire car, on loan as a courtesy car, or just bought. Two motors on one driveway, one petrol, one diesel. Your normal forecourt, its pumps now in a different order. A hurried fill en route to Sankey for Penketh with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver used to petrol: exactly when it occurs. With rain, a call coming in, or a car full of children to deal with, your hand simply does what it has always done.
Next time you fill up around Penketh: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what matters.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: many vehicles state the fuel type there.
- One of each in the house? Label the key to your diesel — a coloured fob, a sticker — since intending to remember is not enough.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- While you're thinking about something else, this is an easy mistake to make — so put 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 cars without one. They are a backstop, not a reason to stop checking the pump.
- Stop as soon as you notice. Less petrol in the tank means a thinner mixture. It doesn't change what to do next, which is still not to start the car.
Already put petrol in a diesel around Penketh?
In that case, there's just a short order of things. Leave it unstarted, with your ignition switched off too. If you are still on the forecourt — BP or anywhere else — ask the attendants to help you roll it clear of the petrol pump. Next, 0333 366 0103. We will ask what went in, roughly how much, and if it's been run.
Corrosion and deposits are the trouble with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and see its own Penketh page.
What makes one Penketh petrol in a diesel job cost more than the next
There is no honest single price for this, since the four situations above are four different tasks. Which of them you're in is chiefly what moves the cost. Where the car is counts too, and whether a technician can safely reach it, after the proportion of petrol to what that tank takes.
That's why our engineers ask three queries before costing instead of after: what went in, how much, and if it has run. Given the answers, there is a straight figure rather than a range.
About Penketh
Penketh is a suburban area in Cheshire, situated near the coast and approximately 13 miles from Liverpool. Penketh has a relatively low elevation of around 15 metres above sea level, and is close to nearby places such as Doe Green and Great Sankey. Penketh is characterised by its predominantly semi-detached housing stock, which reflects the typical residential architecture of the region. Penketh is home to a population of around 5729 people, according to recent estimates.
Fuel drain cover in Penketh and across Cheshire
Penketh rests in the WA postcode area, and our teams that answer petrol in diesel calls there work the spots near it as well — Doe Green, Great Sankey and Lingley Green among them. The car does not need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump around Penketh, still?
In that case, you couldn't be in a better place. Switched off it stays; then ring.