Hurst: Petrol in a Diesel Car? How Worried to Be
Likely less than you are now — as long as nobody has started it. "Have I ruined it?" is the first thing everyone around Hurst asks, and the truthful answer is normally no, since petrol resting in a diesel tank harms nothing until it is drawn through the system — by ignition priming, by the starter, or by being driven. Leave the motor off and call Petrol in Diesel — that keeps it like that. Below, you will find what petrol actually does inside a diesel, how far it might have gone, and how to stop it happening to you again.
Inside your engine: what petrol in a diesel really does
Two tasks fall to diesel on its journey through a motor. Before it ignites, it protects — then it ignites. Very fine clearances are built into your injectors and your high-pressure pump, and only your diesel running through keeps their surfaces from grinding together.
Of these two tasks, petrol handles the first badly and the second not at all. The rattling comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication the system rests on, and any pump working on that mix is wearing itself.
Taken together, they make clear the shape the problem takes. Not contact but movement is what does the damage. Petrol in a tank is a fuel problem. 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 the fuel injectors downstream.
Petrol in a diesel around Hurst: how serious is it? Four cases
Filled up, never started. The best case there can be. At a forecourt, and genuinely only there, the petrol is still confined to the tank — because everywhere else your car was driven to get to it. The job is draining and flushing on the spot.
Started for a moment, or just the ignition on. Your system has been bled, so petrol has left the tank and got to your filter and the lines. Normally nothing more than clearing, rinsing and sorting your filter, and so still easy.
Some miles driven, and your pump has spent each of them working on thinned fuel. How hard the car was driven counts as much as how far, and this work takes in the tank, your lines, your filter and clean fuel through the entire circuit. On the school run to Martock Church School, the miles is short. Getting as far as Wells, under 25 miles away, makes a very different job — as does any mileage on the M5, under 15 miles from Hurst, with your engine labouring hard all the way.
Driven on till it complained — knocking, smoke, a ragged idle, a dead throttle. The fuel is not behaving like diesel any more, and the motor is telling you. Whether it is the verge on Hurst, a lay-by or a side road, stop there then leave it. Lasting damage is very unusual when a car is pulled over early, and the fuel drain and flush-through that still come first deal with it.
What Hurst motorists get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — your tank just carries more of the same blend. A diesel fuel system doesn't accept petrol by percentage in the way that guidance presumes.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through finer components: that is how a newer diesel moves its fuel, and so the lubrication matters for more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no damage done." Diesel in a petrol motor generally means a motor that will not run: the driver stops, and so does the harm. While your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running is not the same as fine.
Myth: a two-stroke additive lets you to drive home. It was an old workaround, meant for another fault. It does not put back what petrol has thinned, and the petrol is still in that tank later.
The next start draws petrol back round your pump out of the fuel lines and your filter, where some of it sits once the engine has been run. That's why draining the tank yourself doesn't leave you sorted — a myth. Also, a can of petrol filled by the kerbside is truly risky.
How petrol ends up: petrol in a diesel
A careless moment is rarely the cause, and nobody means to do it. A diesel nozzle generally won't fit a petrol vehicle, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error straightforward, and only in one direction.
It takes place when habit and the vehicle stop matching. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. Your ordinary forecourt, its pumps suddenly in a different order. Fuelling up in a hurry on the way to Crewkerne, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it takes place. Add a back seat full of children, a phone call or rain, and the hand takes over.
How to avoid petrol in a diesel at your next fill-up in Hurst
- Read the 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.
- Many motors state the fuel inside your filler flap or on the cap, so check it on the first fill in any motor you don't know.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a house has one of each. So mark it.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems daft. It works.
- Mistakes like this are straightforward to make while your mind is on something else, and so your phone goes away.
- Add-on devices exist for cars without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol in your tank makes a thinner mixture. What to do next doesn't change, though — still don't fire it up.
Put petrol in a diesel in Hurst already?
The order of things is short, then. Don't start it, and do not switch the ignition on. Yet on the forecourt, at Texaco or anywhere else? Ask the staff to help you roll it away from the pump. Then call 0333 366 0103 and tell us what got in, about how much, and if it has run.
If it was AdBlue rather than petrol, say so. That is a separate issue — corrosion and deposits rather than lost lubrication — and it has its own page for Hurst.
Why one petrol in a diesel job around Hurst costs more than another
Four different tasks lie behind the four situations above — which is why there is no fair single quote. Which of them you're in is chiefly what moves your cost. Where the car is matters too, and whether a van can safely reach it, after the proportion of petrol to what that tank takes.
Three queries come first, before quoting, rather than after — what went in, how much, has it run — and that is the reason. With the replies, you get a straight figure rather than a range.
About Hurst, briefly
Hurst is a small suburban area in Somerset, situated on the riverside at an elevation of 18 metres. Hurst lies near the towns of Martock and Wells, and is surrounded by other nearby places such as Bower Hinton and Coat. Hurst has a population of approximately 844 residents, who mostly live in detached housing. Hurst is located 17.6 miles from Wells and 120.4 miles from London.
Hurst and Somerset: where our fuel drain cover runs
Hurst waits in the TA postcode area, and the teams that answer petrol in diesel calls there work the spots around it as well — Martock, Bower Hinton and Coat among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our technicians work, and your car does not need to come to us.
Still at the petrol pump in Hurst?
The best position there is, then — that is where you are. Keep it switched off, and ring.