Hatfield: Petrol in a Diesel Car? How Worried to Be
Probably less than you are now — as long as nobody has started it. Everyone around Hatfield begins with "have I ruined it?", and the fair answer is generally no: petrol left in the tank of any diesel stays harmless till priming, cranking or driving pulls it into the system. Leave your engine off and ring Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and the way to make sure you never do it again.
Petrol in a diesel: what does it do to the engine?
Passing through an engine, diesel is doing two jobs at once. It protects first, and only then does it burn. What stops the surfaces inside your high-pressure pump and the fuel injectors from wearing against one another is your diesel flowing through them — they're designed to very fine gaps.
Of those two jobs, petrol manages the first poorly and the second not at all. It is runnier than diesel and strips away the lubrication the 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 problem plain. It is circulation that does the harm, not contact. Petrol in the tank is a fuel fault. After your pump has been labouring on that petrol, a mechanical fault has started: whatever is shed by a pump that's wearing travels onward to the injectors with the fuel.
How bad is petrol in a diesel? Four situations we see around Hatfield
The best case there can be: filled up, never started. Only your tank has petrol in it, so the job is draining the tank and cleaning your system where the vehicle sits. This situation can only really occur on a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a short start. Your system has been bled, so petrol has left that tank and reached the fuel filter and the lines. That's usually still a simple job — a drain, a flush, and the filter seen to.
The pump has spent a couple of miles on diluted fuel — that is what driving the car meant. Mileage is only half of it; how hard it was driven counts just as much. Either way this work includes that tank, the lines, the filter and fresh fuel through the entire system. Short trips, like the school run to Travis St Lawrence Church of England Primary School, are one matter. Very different again: a run to Doncaster, under 10 miles away, or any mileage on the M18, under a mile from Hatfield, where your engine kept labouring hard.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The engine is telling you your fuel is no longer acting like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on High Street. The drain and flush still go first, and they deal with it: if a vehicle is pulled over soon, long-term damage is very uncommon.
What Hatfield people get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing comes out when you top up — the tank just holds more of the same mixture. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. A newer diesel runs its fuel through finer parts at higher pressure, which makes the lubrication count more, not less.
One myth that catches drivers out: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally won't run, so the driver stops — and the damage stops with them. A diesel fed petrol normally starts, idles and drives away as though nothing has happened, whilst your pump grinds. A running engine doesn't mean fine.
An outdated workaround for a separate problem is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." The petrol is still in your tank afterwards, and what it has thinned is not put back.
Once your engine has run, part of that petrol sits in the fuel filter and your lines, not the tank — and the next start pulls it right back through the pump. So the myth "drain that tank yourself and you're sorted" does not hold. Also, a can of petrol filled at the roadside is truly risky.
How does petrol in a diesel occur?
It's seldom carelessness, and no one does it on purpose. 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 motor at all. The forecourt makes it easy, and the mistake runs one way.
When routine and the car stop matching, it takes place. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. Rushing for a train outside Hatfield & Stainforth and filling up en route. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. With rain, a call arriving, or a car full of children to deal with, the hand simply does what it has always done.
Next time you fill up in Hatfield: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is only a clue.
- Many cars state the fuel type inside your filler flap or on the cap, and so check there on the first fill in any motor you don't know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a household with one of each.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It works.
- Mistakes like this are simple to make while your mind is on something else, and so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for motors without one. They are a safety net, not a reason to stop checking the pump.
- Noticing it halfway? Stop there and then. A thinner mixture follows from less petrol inside that tank, but the next stage remains the same: don't start the car.
Petrol already in a diesel around Hatfield? Start here
The order of things is short, then. Don't fire it up, and don't switch the ignition on. Yet on the forecourt, at JET or anywhere else? Ask the attendants to help you roll it clear of the petrol pump. Then phone 0333 366 0103 and tell us what went in, roughly how much, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate problem — Hatfield has a page all for it.
One petrol in a diesel job in Hatfield costs more than another. Why?
An honest single price doesn't exist here: four scenarios, four separate tasks. The scenario itself does most of the work of moving your cost. The proportion counts next, meaning how much of your tank is petrol, followed by the position of your car and whether reaching it is safe for our van.
What was put in, how much, and whether it has run — three questions our technicians ask before costing, not after, for precisely that reason. Those replies are what turn a range into one firm number.
About Hatfield itself
Hatfield is a village in South Yorkshire, situated near the town of Doncaster and close to the surrounding communities of The Lings, Dunscroft, and Slay Pits. Hatfield lies inland, with an elevation of around 10 metres, and is characterized by its predominantly semi-detached housing stock. Hatfield is located approximately 6.6 miles from Doncaster and 147.7 miles from London, making it a relatively accessible rural location. Hatfield has a population of around 2415 people, according to recent estimates.
Fuel drain cover around Hatfield and across South Yorkshire
The vans answering petrol in diesel calls around Hatfield, in the DN postcode area, also work the spots near it, The Lings, Dunscroft and Slay Pits among them. The vehicle doesn't need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Still at the petrol pump in Hatfield?
Then you're in the best spot there is. Phone, and keep it switched off.