Pottersheath: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you likely feel. Petrol sitting in a diesel tank does nothing to your motor until 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 everyone around Pottersheath asks, "have I wrecked it?", is usually no. Petrol in Diesel is who to call, with the engine left off, so it stays that way. Below, you will find what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
Your engine and petrol in a diesel: what goes on
Passing through a motor, diesel does two things at once. Oiling comes before burning; it does both. Designed to very fine clearances, the injectors and the pump rely on the diesel moving through them to stop their surfaces wearing against one another.
Badly at the first, not at all at the second: that's petrol. It is thinner than diesel and removes the lubrication the fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the rattling comes from.
Together, those make the shape of the issue plain. It's movement that causes the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. The start of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors beyond it.
Four situations our technicians see in Pottersheath: how serious is petrol in a diesel?
Filled up, and not started: nothing beats it. At a forecourt, and really only there, that petrol is still limited to that tank — since everywhere else the vehicle was driven to reach it. The task is draining and cleaning on the spot.
The ignition switched on, or a brief start. Once primed, the system has drawn petrol out of that tank as far as the filter and the fuel lines. That's usually still a simple task — a drain, a flush, and the fuel filter dealt with.
Driven a couple of miles. Now the pump has spent these miles labouring on thinned fuel. Tank, lines, filter, then clean fuel run through the entire system: that's the work, and the way the car was driven counts as much as the distance. A school run to Oaklands Primary School is one matter. Very different once more: a trip to St Albans, under 10 miles away, or any miles on the A1(M), under a mile from Pottersheath, where the motor never stopped working hard.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. The fuel isn't behaving like diesel any more, and the motor is telling you. Leave it where it has stopped: a lay-by, a side street, the verge on Fallow End. The fuel drain and flush-through still go first, and they deal with it: if a vehicle is stopped soon, lasting damage is very uncommon.
Petrol in a diesel myths Pottersheath people hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Protection matters more on newer diesels, not less, because their fuel runs through smaller components at higher pressure.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it generally will not run, so the driver stops — and the damage stops with them. While the pump grinds, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Fine and running are not the same thing.
Myth: "Add some two-stroke oil and drive it home." It is an old workaround for a separate issue. None of what petrol diluted is put back by it — and afterwards, the tank still holds that petrol.
The next start sends petrol back round the pump from your lines and your filter, where some of that ends up after the motor has run. That is why draining your tank yourself does not leave you sorted — a myth. It is also truly risky to drain petrol into a can at the roadside.
How petrol ends up: petrol in a diesel
A careless moment is seldom the cause, and no one means to do it. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
When routine and the vehicle stop matching, it occurs. A new motor, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to Knebworth. A new-to-you diesel Peugeot 308, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. Add rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up around Pottersheath
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Trust the label on the pump, not the colour.
- Plenty of cars state the fuel inside your filler flap or on the cap, and so check it on the first fill in any vehicle you don't know.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, for a house with one of each.
- It seems daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Less petrol makes a weaker mixture, so stop the moment you notice — while remembering that the next step is unchanged. It is still not to start the vehicle.
Already put petrol in a diesel in Pottersheath?
Then the order of things is brief. Do not switch the ignition on, and do not crank it. Ask the attendants to help you roll it clear of the pump if you are still at the forecourt, whether that is BP or somewhere else. Next, 0333 366 0103. We will ask what got in, about how much, and if it's been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different problem — Pottersheath has a page just for it.
One petrol in a diesel task around Pottersheath costs more than another. Why?
Four different jobs lie behind the four scenarios above — which is why there's no fair single quote. Mostly, the cost moves with which situation you're in. After that it is the share — how much petrol was put in against how much the tank takes — and then where the vehicle is and whether a technician can get to it safely.
Three questions come first, before quoting, rather than after — what was put in, how much, has it run — and this is the reason. Their replies are what turn a range into one firm number.
About Pottersheath, for a moment
Pottersheath is a small village in Hertfordshire, situated inland at an elevation of around 124 metres. Pottersheath lies approximately 23.9 miles from London and 8.9 miles from St Albans, with nearby villages including Rableyheath and Oaklands. Pottersheath has a population of around 533 people, predominantly living in detached houses.
Fuel drain cover in Pottersheath and across Hertfordshire
Pottersheath sits in the AL postcode area, and our teams that answer petrol in diesel call-outs there work the spots around it as well — Rableyheath, Oaklands and Woolmer Green among them. Our engineers drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Pottersheath and still at the pump?
No position is better: that is where you are. Keep the car switched off, then ring.