Should You Worry? Petrol in a Diesel Car in Assington
Provided it has not been started, worry far less than you likely are. "Have I wrecked it?" is the first question anyone around Assington asks, and the truthful answer is usually no, because petrol left in a diesel tank harms nothing till it is dragged through your fuel system — by ignition priming, by your starter, or by being driven. Leave the engine off and phone Petrol in Diesel — that is how you keep it like that. Below, this page sets out what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
Inside the motor: what petrol in a diesel does
On its way through an engine, diesel has two jobs. Before it ignites, it protects — then it burns. Designed to extremely fine tolerances, the injectors and your pump depend on the diesel moving through them to stop their surfaces wearing against one another.
Poorly at the first, not at all at the second: that is petrol. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication the fuel system rests on, and any pump running on that blend is wearing itself.
Put those together and the shape of the trouble is clear. The damage is done by movement, not by contact. Petrol in the tank is a fuel problem. A pump that has been running 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 further on.
How serious is petrol in a diesel? Four scenarios we see around Assington
Filled but never started — the best it gets. On a forecourt, and truly only there, the petrol is still confined to your tank — since everywhere else the vehicle was driven to reach it. The job is emptying and cleaning on the spot.
The ignition turned on, or a short start. Once primed, the fuel system has drawn petrol out of that tank as far as your filter and the fuel lines. That is usually still a straightforward task — a drain, a flush, and your filter seen to.
The pump has spent a couple of miles on weakened fuel — that's what driving it does. Tank, lines, filter, then clean fuel run through the entire circuit: that's the work, and the way the vehicle was driven counts as much as the distance. Short trips, like the school run to Boxford Church of England Voluntary Controlled Primary School, are one thing. A run as far as Colchester, under 10 miles away, is a very different job. So is any distance on the M11, under 50 miles from Assington, where the motor has been running hard throughout.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The motor is telling you the fuel is no longer behaving like diesel. Leave it wherever it stops: a lay-by, a quiet street, the verge on Vicary Estate. Lasting damage is very uncommon if a car is pulled over quickly, and the fuel drain and flush that still come first take care of it.
What Assington motorists get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing comes out when you top up — the tank just carries more of the same blend. A diesel fuel system does not tolerate petrol by percentage in the way that advice presumes.
Not so: a newer diesel copes with a bit of petrol. If anything, the reverse. Lubrication counts more on newer diesels, not less, since their fuel passes through smaller parts at higher pressure.
This is the one that catches drivers. Myth: "If it starts and drives, there is no harm done." A petrol motor fed diesel usually will not run, so the motorist stops and the harm stops with them. A diesel fed petrol normally starts, idles and drives away as though nothing has happened, while your pump wears. Running is not the same as fine.
Myth: a two-stroke additive lets you to drive home. It is an old fix, meant for another problem. The petrol is still inside that tank afterwards, and what it has weakened isn't put back.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in the filter and lines, ready to go right back through your pump at the next start. On top of that, petrol cleared into a can by the road is truly risky.
Why petrol in a diesel takes place at all
Carelessness is seldom the cause, and nobody means to do it. One way only, because of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol motor. That's how the forecourt makes it simple.
When routine and the vehicle stop matching, it occurs. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. A hurried fill on the way to Bures with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it happens. Your hand does what it has always done when you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel on your next fill-up in Assington
- Green for unleaded and black for diesel is usual in the UK — but not on each forecourt. Trust the label on the pump, not the colour.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before the first fill: plenty of vehicles state the fuel there.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, in a house with one of each.
- "Diesel", out loud, before you pick up the nozzle — each time a new or hired car needs its first tank. It seems daft. It works.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices are available for motors without one, and some diesels come with a filler that will not take a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside that tank means a weaker blend. It does not change what to do next, which is still not to start it.
Petrol already in a diesel in Assington? Begin here
In that case, there's just a short order of things. Leave it unstarted, with your ignition off too. If you're still at the forecourt — Esso or anywhere else — ask the staff to help you push it clear of the pump. Phone 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and if it has run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Assington page.
Assington petrol in a diesel tasks: why one costs more than another
Four separate jobs sit behind the four situations above — which is why there is no fair single price. The scenario itself does most of the work of moving the cost. The ratio matters next, meaning how much of that tank is petrol, and then the location of the car and whether getting to it is safe for our van.
That's why our engineers ask three questions before quoting instead of after: what got in, how much, and if it's run. Those answers change a range into a straight figure.
About Assington, briefly
Assington is a small village in Suffolk, situated inland at an elevation of around 60 metres, and is located approximately 53 miles from London. Assington lies near the larger town of Colchester, which is about 9 miles away, and is also close to other nearby places such as Leavenheath and Hagmore Green. Assington has a population of around 514 people and is characterised by predominantly detached housing. Assington is surrounded by the rolling countryside of the Suffolk landscape.
Assington and Suffolk: where our fuel drain cover runs
Assington waits in the CO postcode area, and the vans that answer petrol in diesel call-outs there work the locations around it as well — Leavenheath, Hagmore Green and Dorking Tye among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations we work, and your car doesn't need to move to us.
Still at the petrol pump in Assington?
Then you're in the best position there is. Switched off it stays; then ring.