Irthlingborough: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — provided nobody has started it. "Have I ruined it?" is the first thing anyone in Irthlingborough asks, and the truthful answer is normally no, because petrol left in a diesel tank hurts nothing till it's dragged through the fuel system — by ignition priming, by your starter, or by being driven. Keep it that way: leave the motor off then ring Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening again: that is the rest of this page.
The engine and petrol in a diesel: what goes on
Two tasks fall to diesel on its journey round a motor. It ignites, and before it burns it protects. The high-pressure fuel pump and your injectors are built to very fine gaps, and your diesel passing through them is what stops those surfaces from wearing down against one another.
The second job petrol doesn't do at all, and the first it does poorly. The knocking comes from petrol being designed 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 out the protection the system depends on, and any pump running on that blend is wearing itself.
Put those together and the shape of the trouble is plain. Contact does not do the harm — circulation does. Where that petrol is only inside the tank, it's a fault of fuel, nothing more. The start of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
Four scenarios our technicians see around Irthlingborough: how serious is petrol in a diesel?
Filled up, and never started: nothing beats it. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held in the tank alone, it is emptied and rinsed on the spot, and nothing more is needed.
Your ignition switched on, or a short start. Petrol has left the tank and got to the fuel filter and your lines, because the fuel system has been primed. Drain, flush, deal with your filter: still normally straightforward.
The pump has spent a few miles on diluted fuel — that's what driving the car does. How hard your car was driven counts as much as how far, and the work covers the tank, the lines, the fuel filter and fresh fuel through the entire system. On the school run to Irthlingborough Junior School, the mileage is small. Very different once more: a trip to Milton Keynes, under 25 miles away, or some distance on the A1(M), under 25 miles from Irthlingborough, where your engine never stopped working hard.
Driven till it complained. Clattering, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is your motor reporting fuel that no longer runs like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Church Street. What goes first is still the fuel drain and flush, and that sorts it out, with permanent damage very uncommon if a car is stopped soon.
Petrol in a diesel stories Irthlingborough motorists hear
"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 idea behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through finer parts: that's how a current diesel handles its fuel, so the protection matters more, not less.
"It starts, it drives, so no harm done" — the myth that catches more people than any other. A petrol motor fed diesel normally won't run, so the driver stops and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump wears. Running does not mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an old workaround for a separate fault. It does not put back what petrol has diluted, and the petrol is still in your tank after that.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the filter and lines, waiting to go right back through the pump on your next start. On top of that, petrol drained into a can by the road is genuinely risky.
How it happens: petrol in a diesel
It is rarely carelessness, and nobody 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 mostly won't go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
Routine and the car falling out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. A train to catch, and a rushed fill en route to Wellingborough. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver accustomed to petrol: precisely when it occurs. With rain, a call arriving, or a car full of children to deal with, your hand simply does what it has always done.
Next time you fill up in Irthlingborough: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is just a hint.
- Plenty of motors state the fuel inside the filler flap or on the cap, and so check it on your first fill in a car you do not know.
- One of each in the house? Label the key to the diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices are available for vehicles without one. They are a backstop, not a reason to stop checking the pump.
- As soon as you realise, stop: less petrol inside your tank means a thinner blend. What to do next does not change, though — still do not fire it up.
Irthlingborough: already put petrol in a diesel?
Then the order of things is short. Don't switch the ignition on, and don't crank it. If you are still on the forecourt — Shell or anywhere else — ask the attendants to help you push the car away from the pump. Phone 0333 366 0103 next, with three facts — your fuel, the approximate amount, and if it has run.
Say so if it was AdBlue rather than petrol: it's a different problem, with its own page for Irthlingborough, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel job in Irthlingborough costs more than another
The four situations above are four separate tasks, so no single price for this would be fair. Which of them you are in is chiefly what shifts your cost. Two things come after that: the petrol that got in as a proportion of what the tank takes, then the spot the vehicle is in and whether our van can get to it safely.
Three queries come first, before quoting, rather than after — what got in, how much, has it run — and this is the reason. With those answers, there is a straight figure instead of a range.
About Irthlingborough
Irthlingborough is a town in Northamptonshire, situated on the lakeside at an elevation of 61 metres, with semi-detached housing being the predominant type of accommodation. Irthlingborough lies approximately 20.5 miles from Milton Keynes and 60.2 miles from London, making it a commuter town with good connections to major cities. Irthlingborough is surrounded by nearby places such as Higham Ferrers, Warmonds Hill, and Little Addington, and has a population of around 8406 residents. Irthlingborough's lakeside setting provides a unique environment for the town's residents and visitors.
Irthlingborough and Northamptonshire: where our fuel drain cover runs
Petrol in diesel call-outs in Irthlingborough — part of the NN postcode area — go to vans that likewise cover the places about it, Higham Ferrers, Warmonds Hill and Little Addington among them. The car does not need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Irthlingborough and still at the pump?
In that case, you couldn't be in a better spot. Keep it off. Phone.