Blundeston: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you probably feel. "Have I wrecked it?" is the first thing everyone in Blundeston asks, and the truthful answer is normally no, because petrol left in a diesel tank harms nothing until it's dragged through your fuel system — by ignition priming, by the starter, or by driving. Petrol in Diesel is who to call, with your engine left off, so it stays that way. What petrol really does to a diesel, how to judge how far it has gone, and how to stop it from happening again: that's the remainder of this page.
Petrol in a diesel: what does it do to the engine?
Diesel has two jobs on its way through a motor. It lubricates first, and only then does it burn. What stops the surfaces inside the high-pressure pump and your injectors from wearing against one another is the diesel flowing through them — they're made to extremely fine gaps.
The second job petrol doesn't do at all, and the first it does poorly. The rattling comes from petrol being designed not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system hinges on, and any pump working on such a mixture is wearing itself.
Put those together and the shape of the issue is plain. Not contact but movement is what causes the damage. Where that petrol is only in your tank, it is an issue of fuel, nothing more. 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 your fuel to the injectors further on.
Petrol in a diesel around Blundeston: how serious is it? Four cases
Filled up, and not started: nothing beats it. That petrol is in the tank and only that tank, and the task is a drain and a flush where your car sits. This is the one situation that can only truly happen at a forecourt, as anywhere else the car has been driven to get there.
Started for a moment, or just your ignition on. Petrol has come out of your tank and reached the fuel filter and your lines, because the fuel system has been primed. Drain, flush, see to the fuel filter: still usually straightforward.
Some miles driven, and the pump has spent each of them labouring on weakened fuel. How hard your car was driven counts as much as how far, and the work takes in your tank, the fuel lines, your filter and fresh fuel through the entire circuit. On the school run to Blundeston Church of England Voluntary Controlled Primary School, the mileage is short. Any distance on the M11, over 50 miles from Blundeston, means the engine has worked hard throughout, and a run to Norwich, under 25 miles away, is a very different job as well.
Driven on till it complained — clattering, smoke, a ragged idle, a soft throttle. The fuel isn't behaving like diesel any more, and your motor is saying so. Pull up where you are — on the verge on Church Road, at the kerb, down a side road — and don't move it. Permanent damage is very rare when a car is stopped early, and the drain and flush-through that still go first sort it out.
What Blundeston 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 by topping up — you're left with a bigger tank, still the same mixture. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Protection matters more on modern diesels, not less, since their fuel passes through finer parts at higher pressure.
Myth: "If it starts and drives, there is no harm done." This is the one that fools motorists. Diesel in a petrol motor normally means a motor that won't run: the motorist stops, and so does the harm. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, whilst the pump grinds. Fine and running aren't the same at all.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an outdated fix for a distinct issue. What petrol has thinned remains thinned, and that petrol stays inside the tank regardless.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in the fuel filter and lines, ready to go straight back through your pump on the next start. Besides, petrol cleared into a can by the road is genuinely risky.
How petrol ends up: petrol in a diesel
Carelessness is rarely the cause, and no one means to do it. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol motor at all. So the error runs one way.
It occurs when habit and your car stop matching. A new car, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. A familiar forecourt with the pumps in a different order. A rushed fill en route to Somerleyton with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it takes place. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Preventing petrol in a diesel next time you fill up around Blundeston
- Read the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what matters.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: many vehicles print the fuel type there.
- Mark your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It sounds silly. It does the trick.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- The moment you notice, stop: less petrol inside your tank means a weaker mixture. What to do next doesn't change, though — still don't start it.
Already put petrol in a diesel around Blundeston?
In that case, there is only a short order of things. Starting it is out, and so is turning on your ignition. If you're still on the forecourt — Tesco or anywhere else — ask the staff to help you push it away from the petrol pump. Then phone 0333 366 0103 and tell us what got in, about how much, and if it has run.
Corrosion and deposits form the issue with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Blundeston page.
Why one petrol in a diesel task in Blundeston costs more than another
The four scenarios above are four separate jobs, so no single price for this would be fair. What shifts your cost is chiefly which of them you're in. The ratio counts next, meaning how much of that tank is petrol, and then the position of the car and whether getting to it is safe for our van.
Three questions come first, before quoting, rather than after — what was put in, how much, has it run — and that is the reason. A range becomes a straight figure when the answers are in.
About Blundeston itself
Blundeston is a small village in Suffolk, situated near the coast and approximately 19 miles from Norwich. Blundeston has a population of around 963 people and is characterised by predominantly detached housing. Blundeston sits at a low elevation of 15 metres above sea level, close to nearby places such as Flixton and Lound. Blundeston is also within commuting distance of larger cities, being around 104 miles from London.
Across Suffolk and in Blundeston: fuel drain cover
The vans answering petrol in diesel calls around Blundeston, in the NR postcode area, also work the spots near it, Flixton, Lound and Cuckoo Green among them. Our technicians drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the petrol pump around Blundeston?
Then you're in the best spot there is. Switched off it stays; then call.