Should You Worry? Petrol in a Diesel Car in Ardersier
Likely less than you already are — provided no one has started the car. Petrol resting in a diesel tank does nothing to your engine until something pulls it through the system — the ignition priming your pump, the starter, or the drive on its own. So the truthful answer to the first query everyone in Ardersier asks, "have I ruined it?", is generally no. Keep it that way: leave the motor off then ring Petrol in Diesel. Below, you will find what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Diesel does two tasks on its way through an engine. Before it burns, it protects — and then it burns. What keeps the surfaces inside the high-pressure pump and your injectors from grinding against one another is the diesel flowing through them — they're designed to very fine gaps.
Poorly at the first, not at all at the second: that is petrol. A pump working on a petrol mix is wearing itself out, because petrol is runnier than diesel and takes away the protection your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where any rattling comes.
Seen together, they show what shape the problem takes. It's movement that does the harm, not contact. Petrol in a tank is a fuel issue. After the pump has been labouring on that petrol, a mechanical problem has started: whatever is shed by a pump that's wearing is carried onward to your injectors with the fuel.
Four situations our technicians see in Ardersier: how serious is petrol in a diesel?
Fuelled, and never started: no case is better. Just the tank has petrol in it, and so the job is draining the tank and purging the system where the car sits. This scenario can only truly occur on a forecourt: anywhere else, the car got there by being driven.
Started for a second, or just the ignition on. Your system has been bled, so petrol has left that tank and reached the fuel filter and the fuel lines. That's generally still an easy job — a drain, a flush, and the fuel filter seen to.
Your pump has worked a few miles on thinned fuel — that is what driving the vehicle meant. Mileage is only half of it; how hard it was driven counts equally. Either way the work runs to that tank, your lines, the filter and clean fuel through the whole circuit. Short trips, such as the school run to the local primary school, are one thing. Getting as far as Inverness, under 10 miles away, makes a very different task — as does any distance on the M90, over 50 miles from Ardersier, with the engine labouring hard the whole time.
Driven until it complained. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and your engine is telling you. Pull up on the spot — on the verge on Station Road, at the kerb, down a side road — and do not move it. A vehicle stopped early very rarely has long-term damage, because the fuel drain and the flush, which still go first, take care of it.
What Ardersier people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally leaves a motor that won't run: the driver stops, and so does the harm. A diesel fed petrol generally starts, idles and drives away as though nothing has happened, whilst your pump wears. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a different issue. What petrol has weakened remains thinned, and the petrol remains inside the tank anyway.
Myth: "Drain that tank yourself and you're sorted." After the motor has been run, some of the petrol is no longer in that tank: it's in your filter and your lines, and it goes right back through your pump on the next start. Clearing petrol into a can at the roadside is also truly risky.
Why petrol in a diesel takes place at all
It is seldom carelessness, and no one does it on purpose. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol vehicle. That's how the forecourt makes it easy.
Routine and the vehicle falling out of step is when it happens. A motor that is new to you — a hire car, on loan as a courtesy car, or just bought. Two cars on one drive, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill on the way to Inverness Airport. Exactly the moment it takes place: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. Throw in a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up around Ardersier: avoiding petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what matters.
- The first fill in a new car is the time to check the filler flap — on it, or on the cap, plenty of vehicles state the fuel to use.
- Label the key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Daft, yes, yet it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for the rest. Count it as a safety net, and keep checking the petrol pump.
- Less petrol means a weaker blend, so stop the moment you realise — while remembering that the next stage is unchanged. It's still not to fire it up.
Petrol already in a diesel in Ardersier? Start here
Then the order of things is brief. Don't switch your ignition on, and do not crank it. Ask the attendants to help you roll it away from the petrol pump if you are still at the forecourt, whether that is the nearest petrol station or somewhere else. What was put in, roughly how much, and if it's run: tell us those when you ring 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate issue — Ardersier has a page just for it.
Why one petrol in a diesel task in Ardersier costs more than another
There is no honest single quote for this, because the four scenarios above are four separate jobs. What moves your cost is mostly which of them you're in. Two things come after that: the petrol that got in as a share of what the tank takes, then the spot the vehicle is in and whether a van can reach it safely.
What got in, how much, and whether it's run — three queries our engineers ask before quoting, not after, for exactly that reason. A range turns into a straight figure once those answers are in.
About Ardersier
Ardersier is a small coastal village in the Highland council area, situated near Inverness and overlooking the Moray Firth. Ardersier has a population of around 828 people and is characterised by detached housing. Ardersier sits at a low elevation of 13 metres, close to notable nearby places such as Fort George and Lochside.
Ardersier and Highland: where our fuel drain cover reaches
Ardersier rests in the IV postcode area, and the vans that answer petrol in diesel call-outs there work the spots around it as well — Fort George, Lochside and Easterton among them. Our engineers drain wherever your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump in Ardersier, still?
The best spot there is, then — that is where you are. Call, and keep it switched off.