Petrol in a Diesel Car in Larklands: How Worried Should You Be?
If it hasn't been started, worry far less than you likely are. "Have I wrecked it?" is the first question anyone in Larklands asks, and the truthful answer is normally no, since petrol left in a diesel tank hurts nothing until it's dragged through the system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to phone, with your motor kept off, and so it remains that way. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never repeat it.
The motor and petrol in a diesel: what goes on
Diesel has two jobs on its way through an engine. It protects first, and after that does it burn. Built to very fine clearances, the fuel injectors and your pump rely on your diesel flowing through them to keep their surfaces from wearing against one another.
The second job petrol does not do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, because petrol is thinner than diesel and takes away the protection your fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the rattling comes.
The shape of the trouble is clear once you put those together. It's movement that causes the damage, not contact. 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 working on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors beyond it.
Larklands, petrol in a diesel: four situations, from mild to major
Filled up, and never started: no case is better. On a forecourt, and really only there, that petrol is still confined to that tank — since everywhere else your car was driven to reach it. The job is emptying and purging on the spot.
The ignition switched on, or a short start. Once primed, your system has pulled petrol out of the tank up to your filter and your lines. Drain, flush, deal with the fuel filter: still usually easy.
A couple of miles driven, and your pump has spent each of them running on thinned fuel. The work is the tank, the fuel lines, your filter and clean fuel through the entire circuit, and how hard your car was driven matters as much as how far. Short trips, like the school run to Larklands Infant School, are one matter. Any mileage on the M1, under 3 miles from Larklands, means your engine has worked hard throughout, and a run to Nottingham, under 10 miles away, is a very different job too.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. The motor is telling you the fuel is no longer behaving like diesel. Stop wherever you are — the verge on Sudbury Avenue, a lay-by, a side street — and leave the vehicle where it is. A car stopped quickly very rarely has lasting damage, because the drain and the flush, which still come first, deal with it.
Larklands motorists and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance assumes.
Not so: a modern diesel copes with a bit of petrol. If anything, the reverse. Smaller components and higher pressure are the way a newer diesel runs its fuel, and that makes the protection matter more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that fools drivers. Feed diesel to a petrol motor and it normally won't run, and so the motorist stops — and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, whilst the pump grinds. Fine and running are not the same at all.
An old fix for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still in the tank after that, and whatever it has diluted is not put back.
If the motor has been run, part of the petrol is in your filter and the lines, not that tank — and your next start sends it right back through your pump. So the myth "drain your tank yourself and you're sorted" doesn't hold. Besides, petrol cleared into a can by the road is truly dangerous.
Why petrol in a diesel takes place so easily
Carelessness is seldom the cause, and nobody means to do it. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol vehicle at all. The forecourt makes it easy, and the slip runs one way.
Habit and your car falling out of step is when it happens. Hire cars, courtesy cars, and motors that are new to you. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. Fuelling up in a hurry on the way to Ilkeston, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: exactly when it happens. Add rain, a phone call or a back seat full of children, and the hand does what it has always done.
Larklands people: how to prevent petrol in a diesel next time
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what matters.
- Check your filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on the first fill in a motor you do not know.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, in 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 lift the nozzle off the pump. It sounds silly and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put your phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices exist for the rest. Count it as a safety net, and keep checking the petrol pump.
- Stop as soon as you realise. Less petrol inside the tank means a weaker blend. It does not change what to do next, which is still not to crank it.
Put petrol in a diesel in Larklands already?
In that case, there's only a short order of things. Don't turn the ignition on, and don't fire it up. Ask the attendants to help you push it away from the pump if you're still at the forecourt, whether that is Morrisons or anywhere else. What went in, roughly how much, and whether it's run: tell us that when you ring 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate issue — Larklands has a page all for it.
Why one petrol in a diesel task in Larklands costs more than another
Four separate tasks sit behind the four situations above — which is why there's no honest single price. Which of them you are in is mostly what shifts the cost. Two things follow that: the petrol that got in as a proportion of what the tank takes, then the spot your car is in and whether a technician can reach it safely.
What went in, how much, and whether it has run — three queries our engineers ask before quoting, not after, for precisely that reason. A range becomes a straight figure once those answers are in.
About Larklands, for a moment
Larklands is a suburban area in Derbyshire, situated near the River Erewash at an elevation of around 55 metres. Larklands lies close to the city of Nottingham, approximately 6 miles to the west, and is part of the larger East Midlands region. Larklands has a mix of housing types, with semi-detached homes being particularly prevalent in the area. Larklands is also near several local landmarks, including the Gallows Inn and Ilkeston Junction.
Across Derbyshire and around Larklands: fuel drain cover
Gallows Inn, Ilkeston Junction and Ilkeston are among the spots near Larklands that the same teams work, answering petrol in diesel calls across Larklands's DE postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers drain, and your car does not need to come to us.
At the pump around Larklands, still?
Then you're in the best spot there is. Turned off it stays; then ring.