Should You Worry? Petrol in a Diesel Car in Leominster
Probably less than you are now — provided no one has started it. Petrol sitting in a diesel tank does nothing to your engine till something pulls it through your fuel system — the ignition priming the pump, the starter, or the drive itself. So the fair answer to the first query everyone in Leominster asks, "have I wrecked it?", is usually no. Leave the motor off and phone Petrol in Diesel — that keeps it that way. The remainder of this page covers what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Your engine and petrol in a diesel: what goes on
On its way through a motor, diesel has two tasks. Oiling comes before burning; it does both. Very fine tolerances go into the fuel injectors and your high-pressure pump, and only your diesel flowing through keeps those surfaces from grinding together.
Badly at the first, not at all at the second: that's petrol. It is runnier than diesel and removes the protection the fuel system rests on, so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the knocking comes from.
Taken together, they show what shape the issue takes. It's movement that causes the harm, not contact. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds goes on, borne by the fuel, into the injectors downstream, which is why a pump that has worked on that petrol is where a mechanical issue begins.
How bad is petrol in a diesel? Four situations our engineers see in Leominster
Filled but never started — as good as it gets. At a forecourt, and really only there, that petrol is still limited to the tank — since anywhere else your car was driven to reach it. The task is emptying and flushing on the spot.
Your ignition turned on, or a brief start. The system has been primed, so petrol has left the tank and reached the fuel filter and the fuel lines. Drain, flush, deal with your filter: still normally straightforward.
A couple of miles driven, and the pump has spent every one of them working on weakened fuel. Mileage is only half of it; how hard it was driven counts just as much. Either way the work includes the tank, the fuel lines, your filter and clean fuel through the entire system. A school run to Leominster Primary School is one thing. A run as far as Hereford, under 15 miles away, is a very different job. So is any miles on the M50, under 25 miles from Leominster, where the motor has been working hard throughout.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on West Street. What goes first is still the fuel drain and flush, and that deals with it, with lasting damage very unusual when a vehicle is pulled over soon.
What Leominster people get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up removes nothing; it gives you a fuller tank of the same mix. That advice supposes a diesel fuel system handles petrol by percentage. It doesn't.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through finer parts: that is how a current diesel handles its fuel, and so the protection counts more, not less.
"It starts, it drives, so no harm done" — the myth that catches most drivers than any other. The motorist of a petrol motor fed diesel normally has no choice but to stop, because it will not run, and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Running is not the same as fine.
Not so: a two-stroke additive lets you to drive home. It was an old fix, supposed for another issue. What petrol has diluted remains weakened, and that petrol stays inside the tank anyway.
Myth: "Drain that tank yourself and you're sorted." Once the motor has been run, some of that petrol is no longer inside that tank: it is in the fuel filter and your lines, and it goes straight back through your pump at your next start. Emptying petrol into a can by the kerbside is also genuinely risky.
How does petrol in a diesel occur?
It's seldom carelessness, and no one does it on purpose. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it easy, and the slip runs one way.
The moment routine stops matching your car is the moment it takes place. A new vehicle, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a rushed fill en route to the nearest station. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: precisely when it takes place. Throw in rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up in Leominster: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what matters.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of vehicles print the fuel there.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key when a house has one of each. So mark it.
- It sounds daft and it works: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- While you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a safety net, then keep checking the petrol pump.
- Spotting it mid-fill? Stop at once. A thinner mix follows from less petrol in that tank, yet your next stage stays the same: do not fire it up.
Put petrol in a diesel in Leominster already?
In that case, there's only a short order of things. Starting it is out, and so is switching on your ignition. The staff at the forecourt — whether at Leominster Service Station itself or wherever you filled up — will usually help push it clear of the petrol pump if you ask. Next, 0333 366 0103. We'll ask what went in, about how much, and if it's been run.
Corrosion and deposits are the problem with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Leominster page.
Leominster petrol in a diesel jobs: why one costs more than another
The four situations above are four separate jobs, so no single quote for this would be honest. What shifts your cost is mostly which of them you're in. The proportion counts next, meaning how much of that tank is petrol, followed by the position of the vehicle and whether getting to it is safe for a technician.
Ahead of any quote, not after, come three questions: the fuel that got in, the quantity, and whether it's run. That is why. A range becomes a straight figure when the replies are in.
About Leominster itself
Leominster is a riverside town in northwest Herefordshire, situated on the River Lugg at an elevation of around 80 metres. Leominster lies approximately 11 miles north of Hereford and 122 miles west of London, with nearby neighbourhoods including The Marsh, Newlands, and Ryelands. Leominster has a population of around 9865 people, predominantly living in semi-detached housing.
Across Herefordshire and in Leominster: fuel drain cover
Leominster sits in the HR postcode area, and the vans that answer petrol in diesel calls there work the spots around it as well — The Marsh, Newlands and Ryelands among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our engineers work, and your vehicle doesn't need to move to us.
In Leominster and still at the petrol pump?
No position is better: that is where you now are. Keep the car switched off, and ring.