Sudbury: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, worry far less than you probably are. "Have I ruined it?" is the first question anyone in Sudbury asks, and the honest answer is generally no, because petrol resting in a diesel tank harms nothing till it's drawn through the system — by ignition priming, by the starter, or by driving. Keep it like that: leave the engine off then phone Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening a second time: that's the remainder of this page.
Petrol in a diesel: what does it do to the engine?
Two tasks fall to diesel on its journey round a motor. It burns, and before it ignites it protects. Extremely fine gaps go into your injectors and your high-pressure pump, and only the diesel running through keeps their surfaces from grinding together.
The second job petrol doesn't do at all, and the first it does poorly. It's runnier than diesel and strips away the lubrication your fuel system depends on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
The shape of the trouble is plain when you put those together. It's movement that does the harm, not contact. Any tank with petrol in it is a fuel fault. After the pump has been labouring on that petrol, a mechanical problem has begun: anything shed by a pump that's wearing down travels onward to the fuel injectors with the fuel.
Sudbury, petrol in a diesel: four cases, from mild to major
The best case there can be: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol kept in that tank alone, it is emptied and flushed on the spot, and nothing more is needed.
A moment's running, or just the ignition on. Petrol has left the tank and reached the fuel filter and the lines, because your system has been primed. Drain, flush, deal with the filter: still usually straightforward.
A couple of miles driven, and your pump has spent each of them labouring on diluted fuel. The work is the tank, the lines, the fuel filter and clean fuel through the entire circuit, and how hard the car was driven matters as much as how far. Short trips, such as the school run to Sudbury Primary School, are one matter. Driving as far as Derby, under 15 miles away, makes a very different job — as does any distance on the M42, under 25 miles from Sudbury, with your engine working hard all the way.
Driven until it complained. Knocking, an uneven idle, smoke, a throttle that has gone soft. The motor is telling you the fuel is no longer behaving like diesel. Stop where you are — on the verge on Main Road, at the kerb, down a side road — and don't move it again. The fuel drain and flush still come first, and they take care of it: if a car is pulled over early, long-term damage is very unusual.
Stories Sudbury drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing comes out when you top up — the tank simply holds more of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance assumes.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." Protection matters more on current diesels, not less, since their fuel passes through finer parts at higher pressure.
This is the one that catches drivers. Myth: "If it starts and drives, there's no harm done." Diesel in a petrol motor normally leaves a motor that will not run: the driver stops, and so does the damage. Whilst the pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive it home." It's an old fix for a separate issue. What petrol has weakened stays diluted, and that petrol remains in that tank regardless.
Myth: "Drain your tank yourself and you are sorted." After your engine has run, some of the petrol is no longer in your tank: it is in the fuel filter and the fuel lines, and it goes right back through your pump at your next start. Draining petrol into a can at the roadside is also genuinely hazardous.
How it happens: petrol in a diesel
No one does it on purpose, and it is seldom carelessness. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol vehicle at all. So the error runs one way.
It happens when habit and the car stop matching. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. Your normal forecourt, its pumps suddenly in a different order. Filling up in a hurry en route to Tutbury & Hatton, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: exactly when it takes place. With rain, a call arriving, or children to deal with, your hand simply does what it always has.
How to avoid petrol in a diesel on your next fill-up around Sudbury
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- Check your filler flap. Plenty of motors state the fuel inside the flap or on the cap. Look at it on your first fill in a motor you don't know.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key if a household has one of each. So label it.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car needs its first tank. It seems daft. It works.
- Mistakes like this are easy to make whilst your mind is on something else, and so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to reject a petrol nozzle, and add-on devices exist for cars without one. They are a safety net, not a reason to stop reading the pump.
- Stop the moment you realise. Less petrol inside that tank makes a weaker mixture. It does not change what to do next, which is still not to start the vehicle.
Petrol already in a diesel around Sudbury? Begin here
In that case, there's just a short order of things. Don't turn your ignition on, and don't crank it. If you're still on the forecourt — Texaco or anywhere else — ask the staff to help you roll the car away from the pump. What was put in, about how much, and if it has run: tell us those when you call 0333 366 0103.
Say so if it was AdBlue instead of petrol: it is a different problem, with its own page for Sudbury, because AdBlue brings corrosion and deposits rather than lost lubrication.
What makes one Sudbury petrol in a diesel task cost more than the next
Four separate tasks lie behind the four situations above — which is why there's no honest single price. What moves 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 car and whether getting to it is safe for our van.
That is why our engineers ask three queries before quoting instead of after: what was put in, how much, and whether it's run. Their answers are what turn a range into one firm number.
About Sudbury
Sudbury is a small village in Derbyshire, situated in the East Midlands region of England, with a population of around 589 people. Sudbury sits inland, approximately 74 metres above sea level, and is located about 12 miles from Derby. Sudbury is characterized by its semi-detached housing and is near to other local places such as Aston and Oaks Green. Sudbury is also within a reasonable distance from major cities, with London being around 118 miles away.
Across Derbyshire and around Sudbury: fuel drain cover
The teams answering petrol in diesel calls around Sudbury, in the DE postcode area, also work the places near it, Aston, Oaks Green and Aston Heath among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and the car does not need to come to us.
Sudbury: still at the petrol pump?
In that case, you could not be in a better position. Leave the vehicle turned off, then ring.