How Worried Should You Be? Petrol in a Diesel Car in Nelson
Probably less than you are now — as long as nobody has started the vehicle. Until the ignition primes your pump, your starter turns, or the car is driven, petrol in a diesel tank simply sits there and does nothing. Which makes the truthful reply to the first Nelson query — "have I wrecked it?" — normally no. Leave your motor off and call Petrol in Diesel — that keeps it that way. What petrol actually does to a diesel, how to gauge how far it has gone, and how to keep it from happening a second time: that's the remainder of this page.
The engine and petrol in a diesel: what happens
Passing through an engine, diesel does two things at once. It combusts, and before it burns it lubricates. Designed to extremely fine gaps, the injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Petrol does the first job badly and the second not at all. It's thinner than diesel and strips away the protection your fuel system depends on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Put these together and the shape of the issue is plain. It is circulation that causes the damage, not contact. Any tank with petrol in it is a fuel issue. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to the injectors beyond it.
How bad is petrol in a diesel? Four scenarios our technicians see in Nelson
Fuelled but never started — as good as it gets. On a forecourt, and really only there, the petrol is still confined to the tank — since everywhere else the car was driven to reach it. The task is emptying and cleaning on the spot.
Ignition on, or started for a second. Petrol has come out of the tank and reached the fuel filter and the fuel lines, since your system has been primed. Drain, flush, see to your filter: still usually straightforward.
Those few miles driven meant your pump running on fuel diluted by petrol throughout. How hard your car was driven counts as much as how far, and the work takes in your tank, your lines, the filter and clean fuel through the entire circuit. Short trips, like the school run to Whitefield Infant School and Nursery, are one thing. Any miles on the M65, under a mile from Nelson, means your engine working hard throughout, and a run to Bradford, under 25 miles away, makes a very different task too.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The motor is telling you the fuel is no longer behaving like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Carr Road. A vehicle stopped quickly very seldom has permanent damage, because the fuel drain and the flush, which still come first, sort it out.
What Nelson people 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 will be." Topping up removes nothing; it gives you a fuller tank of the same mixture. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Finer components and higher pressure are how a modern diesel runs its fuel, and that makes the protection count more, not less.
"It starts, it drives, and so there is no harm" — the myth that catches more people than any other. The motorist of a petrol engine fed diesel normally stops, since it will not run, and the damage stops there. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while your pump wears. Running is not the same as fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. What petrol has weakened stays weakened, and that petrol remains inside your tank anyway.
The next start draws petrol back round your pump out of your lines and your filter, where some of it ends up after your engine has run. That's why a DIY tank drain does not leave you sorted — a myth. And, a can of petrol drained at the kerbside is genuinely dangerous.
How petrol ends up: petrol in a diesel
No one does it on purpose, and it is seldom carelessness. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
Habit and your car falling out of step is how it takes place. Courtesy car, hire car, or a motor that's new. One petrol and one diesel on the drive of the same household. The pumps in a different order on a well-known forecourt. Filling up in a hurry on the way to the nearest station, with a train to catch. The first fill-up in a diesel Skoda Octavia after years of driving petrol is precisely the moment it occurs. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Next time you fill up in Nelson: avoiding petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a clue.
- Plenty of vehicles state the fuel type inside the filler flap or on the cap, so check there on your first fill in a car you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key when a home has one of each. So mark it.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds daft. It does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to reject a petrol nozzle, and add-on devices exist for the remainder. Treat it as a safety net, then keep reading the pump.
- The moment you notice, stop: less petrol inside that tank makes a weaker blend. What to do next doesn't change, though — still do not fire it up.
Nelson: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with the ignition switched off too. If you're still on the forecourt — Morrisons or anywhere else — ask the staff to help you roll the car away from the pump. What went in, about how much, and if it's run: tell us those when you phone 0333 366 0103.
Say so if it was AdBlue rather than petrol: it's a different fault, with its own page for Nelson, since AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel task around Nelson costs more than another
There is no honest single price for this, because the four scenarios above are four different tasks. Mostly, your cost moves with which one you are in. Two things come after that: the petrol that got in as a share of what the tank takes, then the spot your car is in and whether a technician can reach it safely.
Ahead of any quote, not after, we ask three questions: your fuel that went in, the quantity, and if it's run. That is why. A range becomes a straight figure once those replies are in.
About Nelson and its setting
Nelson is a town in Lancashire, situated near the lakeside in the North West of England, with a population of around 34736 people. Nelson sits at an elevation of 140 metres, approximately 183 miles from London, and is close to nearby places such as Whitefield, Lomeshaye, and Bradley. Nelson has a predominantly terraced housing stock, reflecting its historical development as a residential area. Nelson is located near the city of Bradford, which is 19 miles away.
Fuel drain cover across Lancashire, Nelson included
Petrol in diesel call-outs in Nelson — part of the BB postcode area — go to vans that also cover the places about it, Whitefield, Lomeshaye and Bradley among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our engineers drain, and your car does not need to move to us.
Nelson: still at the petrol pump?
The best place there is, then — that is where you are. Turned off it stays; then phone.