Should You Worry? Petrol in a Diesel Car in Dean
Not started? Then less worried than you likely are. "Have I ruined it?" is the first thing anyone in Dean asks, and the truthful answer is generally no, since petrol left in a diesel tank harms nothing till it's drawn through your fuel system — by ignition priming, by the starter, or by being driven. To leave it like that, call Petrol in Diesel and leave the engine alone. What petrol really does to a diesel, how to gauge how far it has gone, and how to stop it from happening a second time: that is the rest of this page.
Your engine and petrol in a diesel: what goes on
Diesel has two jobs on its way through a motor. It burns, and before it ignites it protects. The high-pressure pump and the fuel injectors are built to extremely fine gaps, and the diesel passing through them is what keeps those surfaces from wearing against each other.
Of those two tasks, petrol manages the first poorly and the second not at all. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on the blend to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the knocking.
Put these together and the shape of the trouble is clear. The damage is done by movement, not by contact. Petrol in the tank is a fuel problem. After your pump has been running on that petrol, a mechanical fault has started: anything shed by a pump that's wearing travels downstream to the injectors with your fuel.
Four scenarios our engineers see around Dean: how bad is petrol in a diesel?
Filled up, and never started: no case is better. Only that tank has petrol in it, so the task is emptying that tank and purging the system where your car stands. This scenario can only truly occur at a forecourt: anywhere else, your car got there by being driven.
Your ignition turned on, or a brief start. Once primed, the fuel system has pulled petrol from your tank up to the filter and your lines. Still generally simple: drain, flush, and your filter sorted.
Your pump now spent a few miles on diluted fuel — that's what driving the vehicle meant. Miles is only half of that; how hard it was driven matters equally. Either way the work includes that tank, the lines, the fuel filter and clean fuel through the entire circuit. The school run to the local primary school is one thing. A run as far as Edinburgh, under 3 miles away, is a very different task. So is any distance on the M8, under 5 miles from Dean, where the motor has been working hard throughout.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the engine signalling fuel that no longer runs like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Belford Road. A car stopped early very rarely has permanent damage, because the fuel drain and the flush-through, which still go first, take care of it.
Myths Dean people hear about petrol in a diesel
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. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse is true. Myth: "A current diesel can cope with a bit of petrol." A current diesel runs its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally means a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually starts, ticks over and pulls away as if nothing has happened — all the while its pump is wearing. Being able to run is not the same as being fine.
Myth: a two-stroke additive makes it safe to drive home. It was an old workaround, meant for another issue. None of what petrol diluted gets put back by it — and afterwards, the tank still holds that petrol.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol sits in your filter and lines, ready to go straight back through your pump at your next start. And, a can of petrol drained at the kerbside is truly hazardous.
Why petrol in a diesel occurs at all
It is seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol car. That is how the forecourt makes it easy.
When routine and the vehicle stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a well-known forecourt. Fuelling up in a hurry on the way to Haymarket, with a train to catch. Years of petrol motors behind you, a diesel Renault Clio in front of you on the forecourt for its first tank — that's when. The hand does what it has always done once you add rain, a phone call or a back seat full of children.
Preventing petrol in a diesel next time you fill up around Dean
- The label is what counts, so read the petrol pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before the first fill: many cars print the fuel type there.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key if a household has one of each. So mark it.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Tuck your phone away. This is an easy mistake to make while you're thinking about something else.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that will not take a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- Stop the moment you notice. Less petrol in the tank makes a thinner blend. It does not change what to do next, which is still not to crank it.
Petrol already in a diesel around Dean? Begin here
Short and simple, then, is the order of things. Leave it unstarted, with your ignition off too. If you're still at the forecourt — Esso or anywhere else — ask the attendants to help you push it clear of the petrol pump. Next, 0333 366 0103. We will ask what got in, about how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Dean has a page just for it.
What makes one Dean petrol in a diesel task cost more than the next
An honest single quote doesn't exist here: four situations, four separate jobs. Which of them you're in is mostly what shifts the cost. Two things come after that: the petrol that went in as a proportion of what the tank holds, then the spot the car is in and whether a technician can reach it safely.
That is why we ask three questions before quoting instead of after: what got in, how much, and whether it's run. Those answers turn a range into a straight figure.
About Dean itself
Dean is a coastal suburban area in the City of Edinburgh, situated approximately 1.3 miles from Edinburgh city centre. Dean sits at an elevation of 42 metres, overlooking the Firth of Forth, and is characterised by predominantly flat-type housing. Dean is bordered by nearby places such as Coates, West End, and Comely Bank, and is home to a population of around 7739 residents.
Fuel drain cover around Dean and across City of Edinburgh
Dean waits in the EH postcode area, and the vans that answer petrol in diesel jobs there work the places around it as well — Coates, West End and Comely Bank among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places we drain, and your vehicle does not need to come to us.
In Dean and still at the petrol pump?
In that case, you could not be in a better place. Ring, and keep it turned off.