Petrol in a Diesel Car in Swineshead: How Worried Should You Be?
Provided it has not been started, you can worry less than you probably are. Everyone in Swineshead begins with "have I ruined it?", and the honest answer is generally no: petrol resting in that tank of a diesel remains harmless till priming, cranking or driving draws it into the fuel system. Leave the motor off and ring Petrol in Diesel — that keeps it like that. Below, this page sets out what petrol actually does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the engine?
Two jobs fall to diesel on its journey through a motor. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure fuel pump and the injectors from wearing against each other is the diesel passing through them — they're made to very fine clearances.
The second task petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on the mixture wearing itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the knocking.
Together, those make the shape of the issue plain. Contact doesn't do the harm — movement does. Where the petrol is only in the tank, it's a problem of fuel, nothing more. After the pump has been running on that petrol, a mechanical fault has begun: whatever is shed by a pump that is wearing is carried downstream to the injectors with the fuel.
Swineshead, petrol in a diesel: four cases, from mild to significant
Filled up, and never started: no case is better. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it is emptied and rinsed on the spot, and nothing more is needed.
Started for a second, or just the ignition on. The system has been bled, and so petrol has left that tank and got to the fuel filter and your lines. Drain, flush, see to your filter: still normally straightforward.
Your pump has worked a few miles on weakened fuel — that is what driving the vehicle does. Tank, lines, filter, then fresh fuel run through the whole system: that's this work, and the way the vehicle was driven matters as much as the miles. The school run to Swineshead St Mary's Church of England Primary School is one thing. Driving as far as Lincoln, under 50 miles away, makes a very different job — as does any distance on the A1(M), under 50 miles from Swineshead, with the engine running hard the whole time.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That's the engine telling you its fuel has stopped behaving like diesel. Pull up on the spot — on the verge on Church Lane, at the kerb, down a side road — and do not move it again. Lasting damage is very rare if a car is stopped soon, and the fuel drain and flush that still come first deal with it.
What Swineshead people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mix. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Finer parts and higher pressure are how a newer diesel runs its fuel, and that makes the lubrication count more, not less.
One myth that catches motorists out: if it starts and drives, it must be unharmed. The driver of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops with them. Feed petrol to a diesel and it normally fires up, ticks over and drives away as if nothing happened — all while its pump is wearing. Running doesn't mean fine.
An old workaround for a distinct problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." It does not put back what petrol has diluted, and the petrol is still in your tank after that.
Once the motor has been run, part of the petrol sits in the filter and the fuel lines, not your tank — and your next start sends it right back through the pump. So the myth "drain that tank yourself and you are sorted" doesn't stand up. Also, a can of petrol drained by the roadside is genuinely risky.
Petrol in a diesel: how does it occur?
Carelessness is seldom the cause, and nobody means to do it. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slips 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.
It occurs when habit and the vehicle stop matching. Courtesy car, hire car, or a vehicle that is new. Two vehicles on one driveway, one petrol, one diesel. A well-known forecourt with the pumps in a different order. A train to catch, and a hurried fill on the way to the nearest station. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Add a back seat full of kids, a phone call or rain, and the hand wins.
How to prevent petrol in a diesel on your next fill-up in Swineshead
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Many motors state the fuel inside your filler flap or on the cap, so check there on your first fill in any motor you do not know.
- Label your key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- "Diesel", out loud, before you pick up the nozzle — each time a new or hired car needs its first tank. It sounds silly. It does the trick.
- While you're thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Some diesels come with a filler designed to block a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- As soon as you realise, stop: less petrol inside the tank means a thinner blend. What to do next does not change, though — still don't start the car.
Put petrol in a diesel around Swineshead already?
Then the order of things is short. Never start the vehicle, and do not turn the ignition on. The staff on the forecourt — whether at Esso itself or wherever you filled up — will usually help roll it away from the pump if you ask. What went in, roughly how much, and if it's run: tell us that when you phone 0333 366 0103.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits instead of lost lubrication — and it has its own page for Swineshead.
One petrol in a diesel job around Swineshead costs more than another. Why?
Four different jobs lie behind the four situations above — which is why there is no fair single price. The situation itself does most of the work of moving the cost. Where the car is matters too, and whether a van can safely get to it, after the share of petrol to what your tank holds.
Before any quote, not after, we ask three queries: the fuel that was put in, the amount, and if it's run. That is why. A range becomes a straight figure once the replies are in.
About Swineshead and its setting
Swineshead is a village in Lincolnshire, situated in the East Midlands region of England, with a population of around 1934 people. Swineshead sits at a low elevation of approximately 10 metres above sea level, near the villages of Tarry Hill, Drayton, and Baythorpe. Swineshead is characterized by its predominantly detached housing stock, reflecting its rural setting. Swineshead is located about 25 miles from Lincoln and 99 miles from London.
Swineshead and Lincolnshire: where our fuel drain cover reaches
Petrol in diesel calls in Swineshead — part of the PE postcode area — go to teams that likewise cover the places around it, Tarry Hill, Drayton and Baythorpe included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers drain, and your vehicle doesn't need to come to us.
Still at the petrol pump around Swineshead?
Then you are in the best spot there can be. Switched off it remains; then call.