How Worried Should You Be? Petrol in a Diesel Car in Warmsworth
Far less than you likely are, provided it hasn't been started. Everyone in Warmsworth starts with "have I wrecked it?", and the fair answer is usually no: petrol resting inside the tank of any diesel remains harmless till priming, cranking or driving pulls it into the fuel system. Petrol in Diesel is who to call, with the engine kept off, so it remains that way. The remainder of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
What petrol in a diesel does to the motor
Passing through a motor, diesel is doing two jobs at once. It protects first, and after that does it burn. What stops the surfaces inside your high-pressure pump and your injectors from wearing against each other is the diesel passing through them — they're built to very fine clearances.
The second job petrol doesn't do at all, and the first it does badly. The knocking comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the fuel system rests on, and any pump running on that blend is wearing itself.
Combined, those leave the shape of the issue plain. It is movement that causes the harm, not contact. All a tank with petrol in it amounts to is a fuel issue. Once your pump has been running on that petrol, a mechanical problem has begun: whatever is shed by a pump that is wearing down is carried downstream to the injectors with the fuel.
How bad is petrol in a diesel? Four scenarios our technicians see in Warmsworth
Filled but never started — the best it gets. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol kept in the tank alone, it is emptied and cleaned on the spot, and nothing more is needed.
Ignition on, or started for a moment. Once primed, the system has pulled petrol out of your tank as far as your filter and the lines. Still usually simple: drain, flush, and your filter sorted.
Your pump now worked a couple of miles on weakened fuel — that is what driving it meant. Mileage is only half of that; how hard it was driven counts equally. Either way this work runs to your tank, the fuel lines, your filter and clean fuel through the entire system. The school run to Warmsworth Primary School is one thing. Very different again: a run to Doncaster, under 3 miles away, or any distance on the A1(M), under a mile from Warmsworth, where your engine kept running hard.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. The fuel isn't acting like diesel any more, and the motor is saying so. Pull up on the spot — on the verge on High Road, at the kerb, down a side road — and don't move it. A vehicle stopped early very seldom has permanent damage, since the drain and the flush, which still go first, take care of it.
Stories Warmsworth motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. Rather, the reverse. At higher pressure, through smaller parts: that is how a current diesel handles its fuel, so the protection counts more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel normally stops, because it will not run, and the damage stops with them. Feed petrol to a diesel and it usually starts, idles and drives away as if nothing has happened — all the while its pump is wearing. Fine and running are not the same at all.
Not so: a two-stroke additive makes it safe to drive home. It was an old fix, meant for another fault. None of what petrol weakened is put back by it — and afterwards, your tank still contains the petrol.
Myth: "Drain your tank yourself and you are sorted." After the engine has been run, some of the petrol is no longer in the tank: it is in your filter and your lines, and it goes right back through the pump at the next start. And, a can of petrol drained by the kerbside is genuinely dangerous.
Petrol in a diesel: how does it happen?
It is rarely carelessness, and nobody does it on purpose. The forecourt makes it simple: 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 car at all. So the slip runs one way.
When habit and the car stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. Two cars on one driveway, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. Fuelling up in a rush on the way to Conisbrough, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it takes place. Add a back seat full of children, a phone call or rain, and habit takes over.
Warmsworth drivers: how to avoid petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what matters.
- The first fill in a strange motor is the time to check your filler flap — inside it, or on the cap, plenty of motors state the fuel they take.
- 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 meaning to remember.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to block a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop checking the pump.
- Less petrol makes a weaker mix, so stop as soon as you realise — while remembering that the next step is unchanged. It's still not to crank it.
Already put petrol in a diesel around Warmsworth?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off too. The attendants at the forecourt — whether at JET itself or wherever you filled up — will normally help push it clear of the petrol pump if you ask. Then ring 0333 366 0103 and tell us what went in, roughly how much, and if it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Warmsworth has a page all for it.
Warmsworth petrol in a diesel tasks: why one costs more than another
The four situations above are four different jobs, so no single quote for this would be honest. The situation itself does most of the work of moving your cost. Next it is the ratio — how much petrol got in against how much that tank takes — and then where your car is and whether our van can get to it safely.
What got in, how much, and whether it's run — three queries our engineers ask before pricing, not after, for precisely that reason. Those answers change a range into a straight figure.
About Warmsworth, for a moment
Warmsworth is a village situated on the banks of the River Don in South Yorkshire, with a mix of semi-detached housing and a population of around 2482 residents. Warmsworth lies close to the town of Doncaster, approximately 2.7 miles away, and is near other local places such as New Edlington and Sprotbrough. Warmsworth has a relatively low elevation of 40 metres above sea level, reflecting its riverside setting. Warmsworth is located about 144.5 miles north of London, in the Yorkshire and the Humber region.
Fuel drain cover around Warmsworth and across South Yorkshire
Warmsworth rests in the DN postcode area, and our vans that answer petrol in diesel calls there work the places around it as well — New Edlington, Sprotbrough and Sprotbrough Park among them. The vehicle doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the petrol pump in Warmsworth, right now?
Nothing beats it: that is where you are. Leave the car turned off, then ring.