Petrol in a Diesel Car in Breach: How Worried Should You Be?
Less than you probably are, provided it hasn't been started. "Have I ruined it?" is the first question everyone in Breach asks, and the truthful answer is generally no, because petrol resting in a diesel tank harms nothing until it's drawn through the fuel system — by ignition priming, by the starter, or by being driven. Leave your engine off and phone Petrol in Diesel — that keeps it that way. The rest of this page sets out 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 a second time.
Your engine and petrol in a diesel: what happens
Passing through a motor, diesel is doing two jobs at once. It lubricates to begin with, and after that does it burn. Made to extremely fine tolerances, your injectors and your pump depend on the diesel moving through them to keep their surfaces from wearing against one another.
The second task 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 exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication the fuel system rests on, and any pump working on that mix is wearing itself.
Combined, those leave the shape of the problem clear. Contact doesn't do the damage — circulation does. Where the petrol is only inside the tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds travels on, carried by the fuel, into the injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault begins.
Petrol in a diesel around Breach: how serious is it? Four situations
Filled but not once started — the best it gets. That petrol is in that tank and just that tank, and the job is a drain and a flush where the car stands. This is the one scenario that can only really happen at a forecourt, since anywhere else the vehicle has been driven to get there.
Started for a moment, or just the ignition on. The system has been primed, and so petrol has left your tank and reached the filter and your lines. Normally nothing more than draining, cleaning and seeing to the fuel filter, and so still easy.
Driven a few miles. Now your pump has spent these miles working on thinned fuel. Tank, lines, filter, then fresh fuel put through the whole circuit: that's this work, and the way the vehicle was driven matters as much as the miles. Driving the kids to Southbourne Infant School is one sort of trip. A run as far as Chichester, under 10 miles away, is a very different job. So is any distance on the A3(M), under 5 miles from Breach, where your engine has been labouring hard throughout.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. The engine is telling you the fuel is no longer behaving like diesel. Whether it is the verge on Mountwood Road, a lay-by or a side road, stop where you are then leave it. Long-term damage is very unusual if a vehicle is pulled over soon, and the fuel drain and flush that still go first sort it out.
What Breach drivers get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A fuller tank of the same mixture is all it gives, because topping up takes out nothing. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice supposes.
If anything, the reverse holds. Myth: "A newer diesel can cope with a bit of petrol." A newer diesel sends its fuel through finer components at higher pressure, which makes the protection count more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel normally stops, because it will not run, and the damage stops with them. Feed petrol to a diesel and it generally fires up, ticks over and pulls away as if nothing has happened — all while its pump is wearing. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a distinct problem. What petrol has thinned stays weakened, and that petrol stays inside the tank anyway.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in the filter and lines, ready to go straight back through the pump at your next start. It's also genuinely risky to drain petrol into a can at the kerbside.
How does petrol in a diesel happen?
A careless moment is seldom the cause, and no one means to do it. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol motor. That's how the forecourt makes it easy.
It occurs when habit and your car stop matching. Courtesy car, hire car, or a motor that's brand new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps arranged differently. Racing for a train outside Southbourne and filling up en route. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Add 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 Breach: avoiding petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of cars state the fuel type inside the filler flap or on the cap, so check it on the first fill in any car you don't know.
- Label the 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 meaning to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It seems silly and it does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Spotting it halfway? Stop at once. A weaker mixture follows from less petrol in the tank, yet your next step remains the same: don't start the vehicle.
Petrol already in a diesel in Breach? Start here
Then, there's just a short order of things. Leave it unstarted, with your ignition off as well. Yet on the forecourt, at Esso or anywhere else? Ask the staff to help you roll it away from the petrol pump. What was put in, roughly how much, and whether it has run: tell us those when you call 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate issue — Breach has a page all for it.
One petrol in a diesel task around Breach costs more than another. Why?
The four scenarios above are four different tasks, so no single quote for this would be honest. Mostly, your cost moves with which situation you're in. Two things come after that: the petrol that got in as a proportion of what the tank holds, then the place the car is in and whether a van can reach it safely.
Three queries come first, before any quote, rather than after — what was put in, how much, has it run — and this is the reason. The replies turn a range into a straight figure.
About Breach itself
Breach is a small suburban area situated near the coast in West Sussex, with Breach being close to the cities of Chichester and Portsmouth. Breach has a population of around 3103 people and Breach is characterised by its predominantly semi-detached housing stock. Breach is located near other suburban areas such as Southbourne and Prinsted, and Breach sits at a low elevation of approximately 10 metres above sea level.
Breach and West Sussex: where our fuel drain cover reaches
Our teams answering petrol in diesel call-outs around Breach, in the PO postcode area, equally work the spots around it, Southbourne, Inlands and Prinsted included. Our technicians drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Breach and still at the pump?
The best position there is, then — that is where you are. Keep the vehicle switched off, and ring.