Petrol in a Diesel Car in Kilrea: How Worried Should You Be?
Unstarted? Then less worried than you likely are. "Have I ruined it?" is the first question everyone around Kilrea asks, and the truthful answer is normally no, since petrol left in a diesel tank hurts nothing till it's dragged through the fuel system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to phone, with the engine kept off, so it stays that way. Further down, this page sets out what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you again.
Your engine and petrol in a diesel: what goes on
On its way through an engine, diesel does two tasks. Oiling comes before burning; it does both. What keeps the surfaces inside your high-pressure pump and the fuel injectors from wearing against each other is the diesel flowing through them — they're built to extremely fine tolerances.
Of those two tasks, petrol manages the first badly and the second never. The clattering 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 thinner than diesel, it strips away the protection your system depends on, and any pump running on such a blend is wearing itself.
The shape of the trouble is clear when you put those together. It is circulation that does the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the injectors further on.
Petrol in a diesel around Kilrea: how serious is it? Four cases
Fuelled, and not started: nothing beats it. That petrol is in your tank and just the tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only really occur at a forecourt, as anywhere else the car has been driven to get there.
A brief spell of running, or merely your ignition on. Once primed, your system has drawn petrol out of that tank up to your filter and the lines. Still usually simple: drain, flush, and the filter sorted.
Those few miles on the road were the pump running on fuel weakened by petrol throughout. How hard the car was driven matters as much as how far, and this work covers that tank, the lines, your filter and clean fuel through the whole circuit. The school run to the local primary school is one matter. Getting as far as Derry, under 50 miles away, makes a very different job — as does any distance on the M77, over 50 miles from Kilrea, with the engine working hard the whole time.
Driven until it complained. Knocking, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Whether it's the verge on Wallace Cottages, a lay-by or a side street, stop where you are then leave it. The fuel drain and flush still come first, and they take care of it: when a vehicle is pulled over soon, permanent damage is very rare.
What Kilrea drivers get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Topping up removes nothing; it gives you a bigger tank of the same mix. That advice assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel runs its fuel through smaller components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that catches motorists. A petrol engine fed diesel usually will not run, so the motorist stops and the damage stops with them. Whilst the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running is not the same as fine.
Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, supposed for another problem. The petrol is still inside your tank afterwards, and what it has thinned isn't put back.
The next start sends petrol back round your pump from the lines and your filter, where some of that sits once the motor has run. That is why draining your tank yourself doesn't sort it — a myth. On top of that, petrol drained into a can by the road is truly dangerous.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and no one does it on purpose. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol motor. That is how the forecourt makes it easy.
Habit and the vehicle getting out of step is how it occurs. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Fuelling up in a hurry on the way to the nearest station, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: precisely when it happens. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up around Kilrea
- The label is what matters, and so check the petrol pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- In a car you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of motors print the fuel type there.
- Label the key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds silly and it does the trick.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for the remainder. Treat it as a safety net, and keep checking the pump.
- Stop the moment you notice. Less petrol in your tank means a thinner blend. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Kilrea?
Then, there is just a short order of things. Starting it is out, and so is switching on your ignition. The staff at the forecourt — whether at the nearest petrol station itself or wherever you filled up — will normally help push it away from the pump if you ask. What got in, about how much, and whether it's run: tell us those when you ring 0333 366 0103.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Kilrea page.
What makes one Kilrea petrol in a diesel task cost more than the next
Four different jobs sit behind the four scenarios above — which is why there is no honest single price. Chiefly, your cost shifts with which one you're in. Two things follow that: the petrol that was put in as a share of what the tank takes, then the place the car is in and whether a technician can get to it safely.
That's why we ask three questions before costing instead of after: what got in, how much, and if it's run. With those replies, there is a straight figure instead of a range.
About Kilrea, briefly
Kilrea is a small locality in County Londonderry, situated inland at an elevation of 38 metres. Kilrea lies near the towns of Garvagh and Rasharkin, and is approximately 28 miles from Derry. Kilrea is characterised by its predominantly detached housing stock, reflecting its rural setting. Kilrea is a relatively small community, with a population of around 734 people.
Fuel drain cover in Kilrea and across County Londonderry
Petrol in diesel jobs around Kilrea — part of the BT postcode area — go to vans that likewise cover the places about it, Garvagh, Rasharkin and Finvoy among them. Our technicians drain wherever the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the pump in Kilrea?
Then you're in the best place there is. Keep it off. Ring.