Derrynaflaw: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, provided it has not been started. "Have I wrecked it?" is the first question anyone in Derrynaflaw asks, and the truthful answer is generally no, because petrol resting in a diesel tank hurts nothing until it's dragged through the system — by ignition priming, by your starter, or by being driven. Keep it like that: leave the engine off and phone Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's travelled, and how to stop it from happening again: that's the rest of this page.
Petrol in a diesel: what does it do to the engine?
Diesel has two jobs on its way through a motor. It ignites, and before it ignites it protects. The high-pressure fuel pump and the fuel injectors are made to very fine tolerances, and the diesel passing through them is what stops those surfaces from wearing down against one another.
The second job petrol doesn't do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and takes away the protection the fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where any knocking starts.
The shape of the trouble is plain once you put those together. Contact doesn't do the harm — circulation does. Where that petrol is only inside the tank, it's a problem of fuel, nothing more. A pump that has been running on that petrol is the beginning 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 Derrynaflaw: how serious is petrol in a diesel?
Fuelled but never started — the best it gets. Only that tank has petrol in it, and so the task is clearing that tank and rinsing the fuel system where the vehicle sits. This situation can only really happen on a forecourt: anywhere else, the car got there by being driven.
Your ignition switched on, or a short start. Once primed, the fuel system has drawn petrol out of your tank up to the fuel filter and the lines. Drain, flush, see to the filter: still usually simple.
The pump has spent a couple of miles on weakened fuel — that is what driving the car meant. Distance is only half of that; how hard it was driven matters equally. Either way this work includes the tank, the lines, your filter and clean fuel through the entire system. Short trips, such as the school run to the local primary school, are one matter. Any distance on the M77, over 50 miles from Derrynaflaw, means the motor working hard throughout, and a run to Derry, under 15 miles away, is a very different job as well.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the engine is saying so. Whether it is the verge on Crown Street, a lay-by or a side street, stop where you are and leave it. The drain and flush-through still go first, and they take care of it: when a vehicle is pulled over early, permanent damage is very rare.
Myths Derrynaflaw drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — that tank simply holds more of the same mixture. Percentage isn't how a diesel fuel system copes with petrol, however much that advice presumes.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." Protection counts more on newer diesels, not less, since their fuel runs through smaller components at higher pressure.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump wears. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated workaround for a distinct problem. The petrol is still in the tank afterwards, and what it has weakened is not put back.
If your engine has run, part of that petrol is in the fuel filter and the lines, not that tank — and the next start sends it straight back through your pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Draining petrol into a can at the roadside is also really risky.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and no one does it on purpose. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it simple, and the mistake runs one way.
It takes place when habit and the vehicle stop matching. Hire cars, courtesy cars, and vehicles that are new to you. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A rushed fill en route to the nearest station with a train to catch. Years of petrol vehicles behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
Next time you fill up around Derrynaflaw: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is only a hint.
- Many cars state the fuel inside the filler flap or on the cap, so check there on the first fill in a motor you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a home with one of each.
- It sounds silly and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Mistakes like this are straightforward to make while your mind is on something else, and so the phone goes away.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Less petrol makes a thinner mix, so stop the moment you notice — while remembering that your next stage is unchanged. It's still not to crank it.
Petrol already in a diesel in Derrynaflaw? Start here
The order of things is short, then. Starting it is out, and so is turning on the ignition. The attendants at the forecourt — whether at the nearest petrol station itself or wherever you filled up — will usually help roll it clear of the pump if you ask. Then call 0333 366 0103 and tell us what was put in, roughly how much, and if it's run.
If it was AdBlue rather than petrol, say so. That is a different issue — corrosion and deposits instead of lost protection — and it has its own page for Derrynaflaw.
Derrynaflaw petrol in a diesel jobs: why one costs more than another
A fair single quote does not exist here: four scenarios, four separate tasks. Which of them you are in is mostly what shifts your cost. Two things follow that: the petrol that went in as a share of what the tank takes, then the place the car is in and whether a van can get to it safely.
What went in, how much, and whether it has run — three questions we ask before costing, not after, for exactly that reason. Given those answers, you get a straight figure instead of a range.
About Derrynaflaw
Derrynaflaw is a small locality in County Londonderry, situated inland at an elevation of 86 metres. Derrynaflaw lies approximately 14 miles from Derry, near the settlements of Dungiven and Gortnahey. Derrynaflaw is characterised by its predominantly detached housing stock, reflecting its rural setting. Derrynaflaw has a population of around 688 residents, according to recent estimates.
Derrynaflaw and County Londonderry: where our fuel drain cover reaches
Our vans answering petrol in diesel jobs in Derrynaflaw, in the BT postcode area, also work the places around it, Dungiven, Gortnahey and Burnfoot included. No need to move the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places where we work.
In Derrynaflaw and still at the petrol pump?
Then, you could not be in a better position. Keep it off. Call.