Should You Worry? Petrol in a Diesel Car in Fen End
Likely less than you are now — provided nobody has started the car. Petrol resting in a diesel tank does nothing to the engine till something pulls it through the fuel system — your ignition priming your pump, your starter, or the drive itself. So the truthful answer to the first query anyone in Fen End asks, "have I wrecked it?", is usually no. Keep it like that: leave the motor off and call Petrol in Diesel. What petrol really does to a diesel, how to judge how far it's gone, and how to keep it from happening a second time: that is the rest of this page.
The motor and petrol in a diesel: what goes on
On its way through a motor, diesel has two tasks. Before it ignites, it lubricates — then it combusts. What keeps the surfaces inside your high-pressure pump and the fuel injectors from wearing down against each other is the diesel flowing through them — they are made to extremely fine clearances.
Petrol does the first job poorly and the second not at all. It is thinner than diesel and strips away the lubrication the system hinges on, so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Together, those make the shape of the issue clear. The harm is done by movement, not by contact. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, borne by the fuel, into your injectors further along, which is why a pump that has worked on that petrol is where a mechanical problem starts.
Petrol in a diesel around Fen End: how bad is it? Four cases
Fuelled, and not started: nothing beats it. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol held inside the tank alone, it is drained and purged on the spot, and nothing more is needed.
The ignition turned on, or a short start. Once primed, the system has drawn petrol out of your tank as far as the fuel filter and the lines. That's normally still a simple job — a drain, a flush, and your filter dealt with.
Those few miles driven were the pump running on fuel weakened by petrol throughout. How hard the car was driven counts as much as how far, and this work covers your tank, the fuel lines, the filter and fresh fuel through the entire circuit. On the school run to The Donington Cowley Endowed Primary School, the mileage is small. Driving as far as Peterborough, under 25 miles away, makes a very different task — as does any mileage on the A1(M), under 50 miles from Fen End, with the engine labouring hard all the way.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you the fuel is no longer behaving like diesel. Leave it where it stops: a lay-by, a side street, the verge on Malting Lane. The drain and flush still come first, and they deal with it: if a vehicle is stopped quickly, lasting damage is very unusual.
What Fen End motorists get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all it gives, because topping up takes out nothing. That guidance assumes a diesel fuel system tolerates petrol by percentage. It does not.
Not so: a current diesel copes with a bit of petrol. Rather, the reverse. Protection matters more on current diesels, not less, because their fuel passes through more precise parts at higher pressure.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. Any petrol engine fed diesel generally won't run, so the motorist stops and the harm stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile the pump grinds. Running is not the same as fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old workaround, meant for another issue. The petrol is still in your tank afterwards, and whatever it has diluted is not put back.
If your engine has been run, part of that petrol sits in the filter and the lines, not that tank — and the next start sends it straight back through your pump. So the myth "drain that tank yourself and you're sorted" doesn't hold. It's also truly dangerous to drain petrol into a can by the roadside.
Petrol in a diesel: how does it happen?
It is rarely carelessness, and nobody does it on purpose. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol motor at all. So the slip runs one way.
The moment habit stops matching the car is the moment it happens. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. Your usual forecourt, its pumps now in a different order. A hurried fill on the way to Swineshead with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done.
Fen End drivers: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- In a motor you don't know, look inside the flap over your filler or at the cap before your first fill: many motors state the fuel there.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, perhaps, yet it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop checking the petrol pump.
- Spotting it halfway? Stop at once. A thinner mix follows from less petrol inside the tank, but the next stage remains the same: don't crank it.
Put petrol in a diesel around Fen End already?
Short and simple, then, is the order of things. Starting it is out, and so is turning on the ignition. Ask the staff to help you roll it away from the pump if you are still at the forecourt, whether that is Esso or anywhere else. What got in, roughly how much, and if it has run: tell us that when you phone 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate issue — Fen End has a page all for it.
Why one petrol in a diesel task in Fen End costs more than another
There is no fair single price for this, because the four scenarios above are four separate tasks. Which of them you're in is mostly what shifts the cost. Where your car is counts too, and whether a van can safely reach it, after the proportion of petrol to what your tank takes.
Ahead of any quote, not after, we ask three questions: the fuel that got in, its quantity, and if it has run. That's why. A range turns into a straight figure once those replies are in.
About Fen End, for a moment
Fen End is a suburban area in Lincolnshire, situated inland at a low elevation of around 5 metres. Fen End lies near several nearby places, including Donington South Ing, Donington, and Northorpe, and is approximately 22.6 miles from the city of Peterborough. Fen End is characterised by its predominantly detached housing stock, reflecting its residential nature. Fen End is also relatively distant from London, at around 96.3 miles away.
Across Lincolnshire and in Fen End: fuel drain cover
Fen End rests in the PE postcode area, and the teams that answer petrol in diesel call-outs there work the places near it as well — Donington South Ing, Donington and Northorpe among them. We drain wherever the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Fen End and still at the petrol pump?
Then you are in the best place there can be. Leave the car turned off, and ring.