How Worried Should You Be? Petrol in a Diesel Car in Lislea
Provided it hasn't been started, worry far less than you likely are. "Have I ruined it?" is the first question everyone in Lislea asks, and the truthful answer is normally no, since petrol resting in a diesel tank hurts nothing till it is drawn through the system — by ignition priming, by your starter, or by driving. Leave your engine off and call Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and ways to make sure you never repeat it.
Petrol in a diesel: what does it do to your engine?
Two jobs fall to diesel on its route through a motor. Before it burns, it protects — and then it ignites. Very fine tolerances go into the fuel injectors and the high-pressure fuel pump, and just the diesel running through stops their surfaces grinding together.
The second task petrol doesn't do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump on that mixture wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
Seen together, they show what shape the issue takes. The harm is done by circulation, not by contact. Petrol in a tank is a fuel fault. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors further on.
Four situations our engineers see in Lislea: how bad is petrol in a diesel?
Filled up, and not started: nothing beats it. Being on a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held in that tank alone, it is emptied and purged right where it stands, and nothing more is needed.
The ignition turned on, or a short start. Your system has been bled, and so petrol has left your tank and got to the filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually simple.
Your pump has spent a few miles on thinned fuel — that is what driving the car meant. Distance is only half of that; how hard it was driven matters just as much. Either way the work runs to the tank, the fuel lines, the fuel filter and clean fuel through the whole circuit. On the school run to the local primary school, the miles is small. Driving as far as Newry, under 5 miles away, makes a very different job — as does any miles on the M77, over 50 miles from Lislea, with the engine working hard the whole time.
Driven until it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. That's the motor telling you its fuel has stopped behaving like diesel. Stop on the spot — on the verge on Dunskey Street, at the kerb, down a side road — and don't move it again. The drain and flush still go first, and they sort it out: if a vehicle is pulled over early, lasting damage is very rare.
Petrol in a diesel myths Lislea people hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing comes out when you top up — your tank simply carries more of the same blend. Percentage isn't how a diesel fuel system copes with petrol, however much that guidance presumes.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." A current diesel runs its fuel through finer parts at higher pressure, which makes the lubrication matter more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more people than any other. Diesel in a petrol motor generally means a motor that won't run: the driver stops, and so does the harm. Whilst the pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Being able to run isn't the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate problem. What petrol has weakened remains diluted, and that petrol stays inside the tank regardless.
Once your engine has run, part of that petrol sits in the fuel filter and your lines, not the tank — and the next start pulls it straight back through the pump. So the myth "drain the tank yourself and you are sorted" does not hold. Emptying petrol into a can at the kerbside is also genuinely hazardous.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol motor. That is how the forecourt makes it easy.
Habit and your car getting out of step is how it happens. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the driveway of the same household. A forecourt you know, only with its pumps laid out differently. A train to catch, and a hurried fill en route to the nearest station. Years of petrol motors behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Lislea drivers: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is just a hint.
- Many cars state the fuel inside your filler flap or on the cap, and so check it on your first fill in a vehicle you don't know.
- One of each in the household? Label your key to the diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It works.
- Tuck your phone away. This is an easy mistake to make while 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 aftermarket devices are available for the remainder. Count it as a backstop, then keep checking the pump.
- Stop as soon as you realise. Less petrol inside that tank means a thinner blend. It does not change what to do next, which is still not to crank it.
Already put petrol in a diesel in Lislea?
Short and simple, then, is the order of things. Leave it unstarted, with your ignition switched off too. Ask the staff to help you push it away from the petrol pump if you are still at the forecourt, whether that is the nearest petrol station or somewhere else. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it's been run.
Corrosion and deposits form the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Lislea page.
What makes one Lislea petrol in a diesel task cost more than the next
Four separate jobs sit behind the four situations above — which is why there's no honest single price. The scenario itself does most of the work of moving your cost. Two things come after that: the petrol that went in as a share of what that tank holds, then the place the car is in and whether a van can reach it safely.
Before any quote, not after, we ask three questions: the fuel that went in, its volume, and whether it has run. That's why. A range turns into a straight figure when the answers are in.
About Lislea, for a moment
Lislea is a small locality in County Armagh, situated inland at an elevation of 141 metres, approximately 4.6 miles from Newry. Lislea is characterised by its predominantly detached housing stock, reflecting its rural setting. Lislea is close to several nearby villages, including Belleeks, Camlough, and Dorsey, and is home to around 879 residents.
Across County Armagh and around Lislea: fuel drain cover
Lislea waits in the BT postcode area, and the vans that answer petrol in diesel call-outs there work the spots around it as well — Belleeks, Camlough and Dorsey among them. The vehicle does not need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the pump around Lislea?
In that case, you could not be in a better place. Keep it off. Ring.