Petrol in a Diesel Car in Old Brumby: How Worried Should You Be?
Likely less than you already are — as long as nobody has started the vehicle. Until the ignition primes your pump, your starter cranks, or your car is driven, petrol in a diesel tank simply sits there and does no harm. Which means the truthful reply to the first Old Brumby query — "have I ruined it?" — normally no. Petrol in Diesel is who to ring, with the motor left off, so it stays that way. Below, you will find what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
The motor and petrol in a diesel: what goes on
Passing through an engine, diesel is doing two things at the same time. Before it combusts, it lubricates — and then it ignites. The high-pressure pump and the fuel injectors are built to extremely fine tolerances, and the diesel passing through them is what stops those surfaces from grinding against each other.
The second job petrol doesn't do at all, and the first it does badly. The rattling comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication the system rests on, and any pump running on that blend is wearing itself.
Put those together and the shape of the problem is plain. The harm is done by circulation, not by contact. Where that petrol is only in the tank, it's an issue of fuel, nothing more. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors further on.
Four situations our technicians see in Old Brumby: how serious is petrol in a diesel?
The best case there can be: filled up, not once started. At a forecourt, and truly only there, that petrol is still limited to the tank — since everywhere else the car was driven to reach it. The task is draining and rinsing on the spot.
Ignition on, or started for a second. With the system primed, the fuel lines and filter already contain petrol that came from your tank. Still usually straightforward: drain, flush, and the fuel filter sorted.
Those few miles driven were your pump working on fuel weakened by petrol the whole way. The work is your tank, the lines, the filter and fresh fuel through the entire system, and how hard the car was driven counts as much as how far. Driving the kids to Priory Lane Community School is one sort of trip. A run as far as Kingston upon Hull, under 25 miles away, is a very different task. So is any miles on the A1077(M), under 3 miles from Old Brumby, where the engine has been running hard the whole time.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone ragged. What you are hearing is the engine signalling fuel that no longer acts like diesel. Stop wherever you are — the verge on West Common Gardens, a lay-by, a side street — then leave it where it is. The fuel drain and flush-through still go first, and they take care of it: if a vehicle is stopped soon, lasting damage is very unusual.
Old Brumby drivers and the petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. A diesel fuel system does not accept petrol by percentage in the way that guidance supposes.
"Current diesels can handle a little petrol" — a myth, and closer to the reverse. At higher pressure, through smaller components: that's how a modern diesel moves its fuel, so the lubrication matters more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that catches people. Feed diesel to a petrol motor and it generally will not run, and so the driver stops — and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while the pump wears. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different fault. That petrol is still in the tank after that, and what it has diluted is not put back.
Myth: "Drain your tank yourself and you're sorted." Once your engine has run, some of the petrol is no longer in that tank: it is in the fuel filter and your lines, and it goes right back through your pump on the next start. And, a can of petrol drained at the kerbside is genuinely hazardous.
Petrol in a diesel: how does it occur?
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it simple, and the slip runs one way.
When routine and the vehicle stop matching, it takes place. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the drive. The pumps in a different order on a familiar forecourt. Filling up in a hurry en route to Scunthorpe, with a train to catch. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
Old Brumby people: how to prevent petrol in a diesel next time
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what matters.
- The first fill in an unfamiliar car is the time to check the filler flap — inside it, or on the cap, many cars state the fuel they take.
- Mark your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Mistakes like this are simple to make whilst your mind is on something else, so your phone goes away.
- Add-on devices are available for cars without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Less petrol means a thinner mix, so stop the moment you notice — while remembering that your next stage is unchanged. It's still not to start the vehicle.
Put petrol in a diesel around Old Brumby already?
In that case, there's only a short order of things. Don't turn your ignition on, and don't fire it up. If you're still at the forecourt — Applegreen or anywhere else — ask the attendants to help you roll the vehicle clear of the petrol pump. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it has been run.
Say so if it was AdBlue instead of petrol: it is a different fault, with its own page for Old Brumby, since AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel job around Old Brumby costs more than another
Four separate tasks sit behind the four situations above — which is why there is no fair single price. Which of them you are in is chiefly what moves the cost. After that it is the share — how much petrol went in against how much the tank takes — and after that where the vehicle is and whether a technician can get to it safely.
That is why our engineers ask three questions before quoting rather than after: what went in, how much, and whether it has run. A range turns into a straight figure when those answers are in.
About Old Brumby itself
Old Brumby is a suburban area in northern Lincolnshire, situated near the city of Kingston upon Hull. Old Brumby sits at a relatively low elevation of around 50 metres, characteristic of the gently sloping landscape of the region. Old Brumby is part of a larger residential area that includes nearby Brumby, Lincoln Gardens, and Westcliff, with a mix of semi-detached housing predominant in the neighbourhood.
Fuel drain cover around Old Brumby and across Lincolnshire
Petrol in diesel calls in Old Brumby — part of the DN postcode area — go to teams that also cover the spots around it, Brumby, Lincoln Gardens and Westcliff among them. No need to move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Old Brumby: still at the pump?
The best position there is, then — that is where you are. Keep it off. Phone.