Should You Worry? Petrol in a Diesel Car in Pennsylvania
Likely less than you are now — provided nobody has started it. Everyone around Pennsylvania starts with "have I ruined it?", and the honest answer is usually no: petrol resting in the tank of a diesel remains harmless until priming, cranking or driving draws it into your fuel system. Petrol in Diesel is who to call, with your engine left off, and so it remains that way. The rest of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
Inside the motor: what petrol in a diesel really does
Passing through a motor, diesel is doing two jobs at once. Before it combusts, it lubricates — then it combusts. Built to extremely fine tolerances, your injectors and the pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
The second job petrol doesn't do at all, and the first it does badly. A pump running on a petrol mix is wearing itself out, because petrol is thinner than diesel and takes away the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that's where any rattling starts.
Put those together and the shape of the issue is clear. Contact does not do the harm — movement does. All a tank with petrol in it amounts to is a fuel fault. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors downstream.
Four scenarios we see around Pennsylvania: how serious is petrol in a diesel?
The best case there can be: filled up, never started. That petrol is in that tank and just your tank, and the job is a drain and a flush where the car stands. This is the one scenario that can only really take place at a forecourt, as anywhere else the car has been driven to get there.
The ignition switched on, or a brief start. Once primed, your system has pulled petrol from the tank up to your filter and your lines. That's normally still an easy task — a drain, a flush, and your filter dealt with.
Those few miles on the road meant your pump labouring on fuel weakened by petrol throughout. Tank, lines, filter, then fresh fuel run through the entire system: that is this work, and the way the car was driven matters as much as the distance. Short trips, such as the school run to Stoke Hill Infant and Nursery School, are one thing. Very different once more: a run to Exeter, under 3 miles away, or some miles on the M5, under 3 miles from Pennsylvania, where the engine never stopped running hard.
Driven until it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is the engine signalling fuel that no longer acts like diesel. Stop wherever you are — the verge on Beech Avenue, a lay-by, a side street — and leave the vehicle there. Permanent damage is very rare when a car is stopped quickly, and the fuel drain and flush that still come first sort it out.
Pennsylvania motorists and the petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. The assumption behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. At higher pressure, through more precise parts: that is how a current diesel moves its fuel, so the lubrication matters more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. A petrol engine fed diesel usually will not run, so the driver stops and the harm stops with them. Feed petrol to a diesel and it normally starts, ticks over and pulls away like nothing has happened — all 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 different problem. It doesn't put back what petrol has weakened, and the petrol is still in your tank afterwards.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol lies in the fuel filter and lines, ready to go straight back through the pump on the next start. Besides, petrol drained into a can by the road is genuinely dangerous.
How it happens: petrol in a diesel
It is rarely carelessness, and no one does it on purpose. One way only, since of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol motor. That's how the forecourt makes it straightforward.
It happens when routine and the vehicle stop matching. A new motor, a hire car or a courtesy car. Two cars on one drive, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. Fuelling up in a hurry en route to St James' Park, with a train to catch. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Pennsylvania motorists: how to avoid petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on each forecourt. The label is what matters.
- Inspect the filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in any car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, in a home with one of each.
- Before the nozzle leaves the pump the first time you fill a hired or new car, say "diesel" out loud. Daft, yes, yet it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away and keep your mind on the pump.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the petrol pump.
- The moment you realise, stop: less petrol in that tank makes a thinner mixture. What to do next does not change, though — still don't start it.
Pennsylvania: already put petrol in a diesel?
Short and simple, then, is the order of things. Starting it is out, and so is turning on your ignition. Still at the forecourt, at Morrisons or anywhere else? Ask the attendants to help you push the vehicle clear of the petrol pump. What went in, about how much, and if it has run: tell us those when you ring 0333 366 0103.
Say so if it was AdBlue rather than petrol: it is a separate fault, with its own page for Pennsylvania, since AdBlue brings corrosion and deposits instead of lost lubrication.
Pennsylvania petrol in a diesel tasks: why one costs more than another
Four different tasks sit behind the four scenarios above — which is why there's no honest single price. Chiefly, the cost shifts with which one you are in. Where the car is matters too, and whether a van can safely reach it, after the ratio of petrol to what your tank holds.
What was put in, how much, and whether it's run — three queries we ask before pricing, not after, for exactly that reason. With those answers, you get a straight figure rather than a range.
About Pennsylvania, briefly
Pennsylvania is a suburban area located on the outskirts of Exeter in Devon, sitting alongside the River Exe at an elevation of around 99 metres. Pennsylvania is characterized by its predominantly detached housing stock and is situated near other local areas such as St James and Stoke Hill. Pennsylvania benefits from its proximity to Exeter city centre, being just over a mile away, and is also close to historic sites like Polsloe Priory. Pennsylvania has a population of approximately 9438 residents.
Fuel drain cover across Devon, Pennsylvania included
The teams answering petrol in diesel call-outs in Pennsylvania, in the EX postcode area, equally work the spots near it, St James, Stoke Hill and Polsloe Priory included. The vehicle does not need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Pennsylvania and still at the petrol pump?
Then you're in the best spot there can be. Keep it off. Ring.