Petrol in a Diesel Car in Drumquin: How Worried Should You Be?
Less than you likely are, provided it hasn't been started. Till the ignition primes the pump, the starter cranks, or your vehicle is driven, petrol in a diesel tank just rests there and does nothing. Which makes the honest reply to the first Drumquin question — "have I wrecked it?" — usually no. To keep it like that, phone Petrol in Diesel then leave your engine alone. Further down, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Inside your engine: what petrol in a diesel does
On its way through a motor, diesel does two tasks. Before it ignites, it lubricates — and then it ignites. The high-pressure pump and the injectors are designed to extremely fine gaps, and your diesel passing through them is what keeps those surfaces from grinding against one another.
Petrol handles the first job poorly and the second not at all. It is runnier than diesel and takes away the protection the fuel system depends on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the knocking comes from.
Taken together, they make clear the shape the problem takes. It's circulation that causes the damage, not contact. Petrol in a tank is a fuel problem. Whatever a worn pump sheds goes on, borne by the fuel, into the injectors further along, which is why a pump that has been working on that petrol is where a mechanical fault begins.
How serious is petrol in a diesel? Four scenarios we see in Drumquin
Fuelled but never started — the best it gets. Only that tank has petrol in it, and so the task is draining your tank and cleaning the fuel system where your car sits. This scenario can only truly occur at a forecourt: anywhere else, the car got there by being driven.
Started for a moment, or just your ignition on. Once primed, the system has drawn petrol from your tank up to the filter and your lines. Still generally simple: drain, flush, and your filter sorted.
The pump now spent a few miles on thinned fuel — that's what driving it meant. The work is the tank, the lines, the filter and fresh fuel through the whole system, and how hard the car was driven matters as much as how far. Driving the kids to the local primary school is one kind of trip. Getting as far as Derry, under 50 miles away, makes a very different job — as does any mileage on the M77, over 50 miles from Drumquin, with the engine labouring hard all the way.
Driven until it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is your engine reporting fuel that no longer runs like diesel. Whether it's the verge on Rock Street, a lay-by or a side road, stop there and leave it. A vehicle stopped quickly very rarely has long-term damage, because the drain and the flush, which still come first, take care of it.
Drumquin drivers and that 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 won't. A bigger tank of the same mixture is all it gives, because topping up removes nothing. That guidance supposes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication count more, not less.
This is the one that catches people. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor usually means a motor that won't run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually starts, ticks over and pulls away as if nothing has happened — all the while its pump wears. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate fault. The petrol is still inside your tank after that, and whatever it has diluted isn't put back.
If the motor has been run, part of that petrol sits in the fuel filter and your lines, not the tank — and your next start sends it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not hold. Clearing petrol into a can by the roadside is also truly hazardous.
How it happens: petrol in a diesel
It's rarely carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol vehicle at all. The forecourt makes it simple, and the error runs one way.
Habit and the vehicle falling out of step is when it takes place. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. A familiar forecourt with the pumps in a different order. A train to catch, and a rushed fill en route to the nearest station. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Add a back seat full of children, a phone call or rain, and the hand takes over.
Preventing petrol in a diesel next time you fill up in Drumquin
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on each forecourt. The label is what counts.
- The first fill in a strange car is the time to check the filler flap — on it, or on the cap, many cars state which fuel to use.
- Label the 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.
- Before the nozzle leaves the pump the first time you fuel a hired or new motor, say "diesel" aloud. Daft, perhaps, yet it does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, so your phone goes away.
- Add-on devices exist for cars without one, and some diesels come with a filler that will not accept a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Noticing it mid-fill? Stop there and then. A thinner mix follows from less petrol in your tank, yet the next step stays the same: don't fire it up.
Petrol already in a diesel in Drumquin? Begin here
Then the order of things is brief. Do not turn the ignition on, and do not crank it. If you're still at the forecourt — the nearest petrol station or anywhere else — ask the staff to help you push the car clear of the petrol pump. What went in, roughly how much, and if it has run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue instead of petrol: it is a different problem, with its own page for Drumquin, since AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Drumquin petrol in a diesel job cost more than the next
Four different jobs sit behind the four situations above — which is why there's no fair single price. Which of them you are in is chiefly what moves the cost. The proportion counts next, meaning how much of that tank is petrol, followed by the position of your car and whether getting to it is safe for our van.
Three questions come first, before any quote, rather than after — what got in, how much, has it run — and that is the reason. The answers change a range into a straight figure.
About Drumquin, briefly
Drumquin is a small locality in County Tyrone, situated inland at an elevation of around 75 metres. Drumquin lies near several nearby settlements, including Dooish, Gillygooly, and Garvetagh, and is approximately 27 miles from the city of Derry. Drumquin has a population of around 513 people, with a predominance of detached housing. Drumquin is located about 373 miles northwest of London, in the heart of Northern Ireland's countryside.
Fuel drain cover across County Tyrone, Drumquin included
Petrol in diesel jobs around Drumquin — part of the BT postcode area — go to teams that also cover the places round it, Dooish, Gillygooly and Garvetagh included. No need to move your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places we drain.
Still at the petrol pump around Drumquin?
No position is better: that's where you now are. Keep it off. Ring.