East End: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you probably are. "Have I wrecked it?" is the first thing everyone around East End asks, and the truthful answer is usually no, because petrol resting in a diesel tank harms nothing till it's dragged through the system — by ignition priming, by the starter, or by driving. Keep it like that: leave your engine off then call Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and ways to make sure you don't repeat it.
Inside the engine: what petrol in a diesel really does
Two jobs fall to diesel on its journey round a motor. Oiling comes before burning; it does both. Designed to extremely fine clearances, the fuel injectors and the pump depend on your diesel flowing through them to stop their surfaces wearing against one another.
The second task petrol doesn't do at all, and the first it does badly. A pump working on a petrol blend is wearing itself out, since petrol is runnier than diesel and takes away the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where the clattering starts.
Together, those leave the shape of the issue plain. It's circulation that does the damage, not contact. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors further along, which is why a pump that has been working on that petrol is where a mechanical fault starts.
How serious is petrol in a diesel? Four scenarios we see in East End
The best case there can be: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol kept inside the tank alone, it's drained and cleaned on the spot, and nothing more is needed.
A moment's running, or just your ignition on. With the system primed, the fuel lines and filter already contain petrol that came from the tank. Normally nothing more than emptying, rinsing and sorting the filter, and so still simple.
A few miles driven, and the pump has spent every one of them labouring on thinned fuel. How hard the vehicle was driven counts as much as how far, and the work takes in that tank, the lines, the filter and clean fuel through the entire system. Driving the children to Charlton Kings Junior School is one kind of trip. Getting as far as Gloucester, under 10 miles away, makes a very different task — as does any miles on the M5, under 5 miles from East End, with the engine working hard all the way.
Driven on till it complained — clattering, smoke, a lumpy idle, a dead throttle. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Stop wherever you are — the verge on Chase Avenue, a lay-by, a side street — and leave it where it is. What goes first is still the drain and flush, and that deals with it, with permanent damage very rare when a vehicle is stopped early.
Petrol in a diesel myths East End motorists hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. A fuller tank of the same mix is all you get, because topping up removes nothing. The idea behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. Lubrication matters more on current diesels, not less, since their fuel passes through more precise parts at higher pressure.
The myth that catches motorists off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the damage. While the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Being able to run is not the same as being fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated fix for a separate fault. It does not put back what petrol has thinned, and that petrol is still inside your tank later.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol sits in the fuel filter and lines, ready to go right back through your pump at the next start. Emptying petrol into a can at the kerbside is also truly hazardous.
Why petrol in a diesel occurs so easily
No one does it on purpose, and it's seldom carelessness. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol motor at all. So the mistake runs one way.
When habit and your car stop matching, it takes place. Courtesy car, hire car, or a motor that is new. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps now in a different order. Fuelling up in a rush on the way to Cheltenham Spa, with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Throw in a back seat full of kids, a phone call or rain, and the hand takes over.
East End motorists: how to avoid petrol in a diesel next time
- 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 hint.
- In a motor you don't know, look inside the flap over your filler or at the cap before your first fill: many motors print the fuel there.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, in a household with one of each.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems daft. It does the trick.
- Put the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for the rest. Count it as a backstop, then keep reading the pump.
- Stop the moment you realise. Less petrol in your tank makes a thinner blend. It does not change what to do next, which is still not to fire it up.
East End: already put petrol in a diesel?
In that case, there's just a short order of things. Leave it unstarted, with the ignition off as well. Still on the forecourt, at BP or anywhere else? Ask the attendants to help you roll the car clear of the pump. Call 0333 366 0103 next, with three answers — your fuel, the approximate amount, and whether it has run.
If it was AdBlue instead of petrol, say so. That's a different problem — corrosion and deposits instead of lost lubrication — and it has its own page for East End.
One petrol in a diesel job around East End costs more than another. Why?
There's no fair single quote for this, since the four scenarios above are four separate jobs. Which of them you're in is mostly what shifts the cost. Beyond that it's the share — how much petrol got in against how much the tank holds — and then where the vehicle is and whether our van can get to it safely.
What went in, how much, and whether it's run — three questions we ask before costing, not after, for exactly that reason. A range becomes a straight figure once the replies are in.
About East End itself
East End is a suburban area in Gloucestershire, situated on the riverside at an elevation of 94 metres, with detached housing being the predominant type of accommodation. East End lies near the city of Gloucester, approximately 8.9 miles away, and is also close to nearby places such as Charlton Kings and Little Herberts. East End has a population of around 2558 residents and is located in a scenic area with easy access to local amenities. East End is part of the wider Gloucester urban area, yet retains a distinct character of its own.
Across Gloucestershire and around East End: fuel drain cover
Petrol in diesel calls in East End — part of the GL postcode area — go to vans that likewise cover the places around it, Charlton Kings, Little Herberts and Ham included. The vehicle doesn't need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
East End: still at the petrol pump?
In that case, you couldn't be in a better place. Leave the vehicle turned off, then ring.