Pennar: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, if it hasn't been started. Petrol sitting in a diesel tank does nothing to the motor till something draws it through your fuel system — the ignition priming your pump, the starter, or the drive itself. So the truthful answer to the first query everyone in Pennar asks, "have I wrecked it?", is usually no. To leave the car like that, call Petrol in Diesel and leave your motor switched off. What petrol actually does to a diesel, how to judge how far it's gone, and how to stop it from happening again: that's the remainder of this page.
Your engine and petrol in a diesel: what goes on
Passing through a motor, diesel is doing two things at the same time. Before it combusts, it lubricates — and then it ignites. Extremely fine clearances are built into the injectors and the high-pressure pump, and just the diesel running through stops their surfaces grinding together.
The second job petrol does not do at all, and the first it does poorly. The clattering comes from petrol being designed not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection your system hinges on, and any pump running on such a blend is wearing itself.
Together, those make the shape of the problem clear. Contact doesn't do the harm — movement does. Petrol in a tank is a fuel problem. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the fuel injectors further on.
Petrol in a diesel in Pennar: how serious is it? Four cases
Fuelled but not once started — as good as it gets. The petrol is in that tank and just that tank, and the task is a drain and a flush where the car sits. This is the one situation that can only truly happen at a forecourt, as anywhere else your car has been driven to get there.
A brief spell of running, or merely your ignition on. Once primed, the fuel system has drawn petrol out of your tank as far as the fuel filter and the fuel lines. Drain, flush, see to the filter: still normally straightforward.
Your pump has spent a few miles on diluted fuel — that's what driving the vehicle meant. Tank, lines, filter, then clean fuel put through the entire system: that's the work, and the way your car was driven counts as much as the distance. Short trips, such as the school run to the local primary school, are one thing. Any miles on the M4, under 50 miles from Pennar, means the motor working hard throughout, and a run to St Davids, under 25 miles away, is a very different task too.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the engine reporting fuel that no longer behaves like diesel. Pull up where you are — on the verge on Stranraer Lane, at the kerb, down a side road — and do not move it. Permanent damage is very rare if a car is pulled over early, and the drain and flush-through that still go first deal with it.
Myths Pennar drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Topping up removes nothing; it gives you a fuller tank of the same mix. The idea behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. Lubrication counts more on newer diesels, not less, because their fuel passes through more precise parts at higher pressure.
"It starts, it drives, so there is no harm" — the myth that catches most drivers than any other. Diesel in a petrol motor normally means a motor that will not run: the driver stops, and so does the damage. Feed petrol to a diesel and it generally starts, idles and pulls away like nothing has happened — all while its pump is wearing. Running doesn't mean fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old fix for a different fault. The petrol is still inside that tank after that, and whatever it has weakened is not put back.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol lies in your filter and lines, ready to go right back through your pump at the next start. On top of that, petrol emptied into a can by the road is truly hazardous.
How petrol ends up: petrol in a diesel
No one does it on purpose, and it's rarely carelessness. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol car. That's how the forecourt makes it simple.
The moment habit stops matching your car is the moment it occurs. 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. Filling up in a rush en route to Pembroke Dock, with a train to catch. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Throw in rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up in Pennar: preventing petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is just a clue.
- In a car you do not know, look inside the flap over your filler or at the cap before the first fill: plenty of motors state the fuel type there.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key when a house has one of each. So label it.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put your phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and add-on devices exist for the rest. Count it as a safety net, and keep checking the petrol pump.
- Spotting it halfway? Stop at once. A weaker mixture results from less petrol in the tank, but the next step remains the same: do not fire it up.
Petrol already in a diesel in Pennar? Begin here
Then the order of things is short. Don't fire it up, and don't turn your ignition on. If you are still on the forecourt — Asda or anywhere else — ask the staff to help you roll the vehicle away from the pump. Next, 0333 366 0103. We will ask what was put in, about how much, and if it's been run.
If it was AdBlue rather than petrol, say so. That is a separate fault — corrosion and deposits and not lost protection — and it has its own page for Pennar.
What makes one Pennar petrol in a diesel job cost more than the next
An honest single quote doesn't exist here: four scenarios, four separate tasks. What moves your cost is chiefly which of them you are in. Where the car is counts too, and whether our van can safely reach it, after the ratio of petrol to what your tank takes.
Three queries come first, before quoting, rather than after — what got in, how much, has it run — and this is the reason. Those replies turn a range into a straight figure.
About Pennar, for a moment
Pennar is a coastal suburban area in Pembrokeshire, situated near the coast at an elevation of 56 metres. Pennar lies within commuting distance of St Davids, the smallest city in the UK, and is close to nearby places such as Llanreath and Pennar Park. Pennar has a population of around 2044 people, predominantly living in semi-detached housing. Pennar is located approximately 207.6 miles west of London, in the scenic coastal region of southwest Wales.
Fuel drain cover across Pembrokeshire, Pennar included
Pennar rests in the SA postcode area, and the vans that answer petrol in diesel jobs there work the places near it as well — Llanreath, Pennar Park and Bentlass among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations we drain, and the vehicle does not need to come to us.
Pennar: still at the pump?
No position is better: that is where you are. Turned off it stays; then call.