Kibblesworth: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you probably feel. "Have I wrecked it?" is the first question everyone in Kibblesworth asks, and the truthful answer is usually no, since petrol left in a diesel tank harms nothing until it is drawn through your fuel system — by ignition priming, by your starter, or by being driven. To keep the car that way, call Petrol in Diesel and leave the motor alone. The rest of this page covers what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
Inside the engine: what petrol in a diesel really does
Diesel has two tasks on its way through a motor. Before it combusts, it lubricates — then it burns. What stops the surfaces inside the high-pressure fuel pump and the injectors from grinding against each other is the diesel flowing through them — they're designed to very fine gaps.
Of these two tasks, petrol manages the first badly and the second never. A pump working on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the lubrication your fuel system depends on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where any knocking starts.
Taken together, they show the shape the problem has. The damage is done by movement, not by contact. A tank with petrol in it is a fuel problem. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
Four situations our engineers see around Kibblesworth: how serious is petrol in a diesel?
Fuelled, and never started: no case is better. Just the tank has petrol in it, so the job is draining your tank and rinsing the fuel system where your car stands. This scenario can only really take place at a forecourt: anywhere else, your car got there by being driven.
Started for a second, or just the ignition on. Your system has been bled, so petrol has left your tank and got to your filter and your lines. Drain, flush, deal with the filter: still usually straightforward.
A couple of miles driven, and the pump has spent every one of them labouring on diluted fuel. The work is the tank, the fuel lines, the filter and fresh fuel through the entire circuit, and how hard the vehicle was driven counts as much as how far. Driving the kids to Kibblesworth Academy is one sort of trip. Driving as far as Newcastle upon Tyne, under 10 miles away, makes a very different job — as does any mileage on the A1(M), under 3 miles from Kibblesworth, with the motor running hard the whole time.
Driven till it complained. Clattering, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and the motor is saying so. Leave it where it stops: a lay-by, a side street, the verge on Kibblesworth Bank. A vehicle stopped soon very rarely has permanent damage, since the fuel drain and the flush, which still come first, sort it out.
Petrol in a diesel myths Kibblesworth people hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A bigger tank of the same mixture is all you get, because topping up removes nothing. Percentage isn't how a diesel fuel system tolerates petrol, however much that advice assumes.
"Modern diesels can handle a little petrol" — a myth, and nearer the opposite. Finer components and higher pressure are how a modern diesel runs its fuel, and that 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 generally means a motor that will not run: the motorist stops, and so does the harm. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump grinds. A running engine doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. None of what petrol thinned is put back by it — and afterwards, that tank still contains that petrol.
The next start sends petrol back round the pump from the fuel lines and your filter, where some of it sits after your engine has been run. That is why a DIY tank drain does not sort it — a myth. Emptying petrol into a can by the kerbside is also really dangerous.
How does petrol in a diesel take place?
No one does it on purpose, and it is seldom carelessness. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol motor at all. So the error runs one way.
Routine and the vehicle getting out of step is when it takes place. Courtesy car, hire car, or a vehicle that's brand new. Households running one of each, petrol and diesel. Your ordinary forecourt, its pumps now in a different order. Racing for a train at Dunston and filling up en route. Precisely the moment it occurs: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel on your next fill-up in Kibblesworth
- A green handle for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- The first fill in a strange car is the time to check your filler flap — inside it, or on the cap, plenty of vehicles state which fuel to use.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a house with one of each.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away and keep your mind on the petrol pump.
- Some diesels have a filler built to block a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the pump.
- The moment you notice, stop: less petrol inside the tank makes a weaker blend. What to do next does not change, though — still do not start the car.
Petrol already in a diesel around Kibblesworth? Begin here
Then the order of things is brief. Starting it is out, and so is turning on the ignition. Ask the staff to help you push it away from the pump if you are still at the forecourt, whether that's Sainsbury's or anywhere else. Phone 0333 366 0103 next, with three facts — the fuel, the approximate quantity, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different problem — Kibblesworth has a page all for it.
Why one petrol in a diesel job around Kibblesworth costs more than another
A fair single price doesn't exist here: four situations, four separate tasks. Mostly, your cost shifts with which situation you are in. Where the car is matters too, and whether our van can safely reach it, after the proportion of petrol to what that tank takes.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and this is the reason. The answers change a range into a straight figure.
About Kibblesworth itself
Kibblesworth is a village in Tyne and Wear, situated on the riverside at an elevation of 45 metres, with semi-detached housing being the predominant type of accommodation. Kibblesworth lies approximately 5 miles south of Newcastle upon Tyne, near the villages of Lamesley and Old Ravensworth. Kibblesworth has a population of around 1223 residents, who live in a relatively small and quiet community. Kibblesworth is located about 243 miles north of London, in the North East region of England.
Kibblesworth and Tyne and Wear: where our fuel drain cover runs
Lamesley, Old Ravensworth and Lady Park are among the spots around Kibblesworth that the same teams work, answering petrol in diesel jobs across Kibblesworth's NE postcode area. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
In Kibblesworth and still at the pump?
Then you are in the best position there is. Call, and leave it switched off.