How Worried Should You Be? Petrol in a Diesel Car in Kearstwick
Probably less than you already are — provided nobody has started the car. Everyone in Kearstwick starts with "have I ruined it?", and the honest answer is usually no: petrol resting inside that tank of any diesel stays harmless till priming, cranking or driving pulls it into the fuel system. Leave the engine off and ring Petrol in Diesel — that keeps it that way. What petrol actually does to a diesel, how to judge how far it has gone, 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?
Two jobs fall to diesel on its route through a motor. It combusts, and before it combusts it protects. What keeps the surfaces inside the high-pressure pump and your injectors from wearing against one another is your diesel flowing through them — they are built to very fine tolerances.
Of those two tasks, petrol manages the first badly and the second never. It's runnier than diesel and takes away the lubrication the fuel system rests on, so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
Taken together, they make clear the shape the trouble takes. The harm is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel problem. After the pump has been labouring on that petrol, a mechanical problem has started: anything shed by a pump that's grinding travels downstream to your injectors with the fuel.
Petrol in a diesel in Kearstwick: how serious is it? Four situations
Filled but never started — the best it gets. Just the tank has petrol in it, so the task is emptying the tank and cleaning your system where your car sits. This scenario can only truly take place at a forecourt: anywhere else, the vehicle got there by being driven.
A brief spell of running, or just the ignition on. Once primed, the system has drawn petrol from the tank up to your filter and your lines. That is normally still a simple job — a drain, a flush, and your filter seen to.
Those few miles driven were your pump running on fuel weakened by petrol throughout. The work is that tank, your lines, the filter and fresh fuel through the whole circuit, and how hard the car was driven matters as much as how far. On the school run to St Mary's CofE Primary School, the miles is short. A run as far as Lancaster, under 15 miles away, is a very different task. So is any mileage on the M6, under 5 miles from Kearstwick, where your engine has been running hard the whole time.
Driven on until it protested — knocking, smoke, a lumpy idle, a soft throttle. The fuel isn't acting like diesel any more, and the engine is telling you. Stop on the spot — on the verge on B6254, at the kerb, down a side road — and don't move it again. The fuel drain and flush still go first, and they sort it out: if a car is stopped soon, permanent damage is very uncommon.
Myths Kearstwick motorists hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you're left with a fuller tank, still the same mixture. The idea behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. Protection matters more on newer diesels, not less, since their fuel runs through finer parts at higher pressure.
"It starts, it drives, so no harm done" — the myth that trips up more motorists than any other. Diesel in a petrol motor normally means a motor that won't run: the driver stops, and so does the damage. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile your pump grinds. A running engine doesn't mean fine.
Myth: a two-stroke additive lets you to drive home. It was an old workaround, supposed for another problem. None of what petrol thinned is put back by it — and later, that tank still holds the petrol.
If your engine has run, part of that petrol is in the fuel filter and the fuel lines, not your tank — and your next start pulls it straight back through the pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Besides, petrol cleared into a can by the road is truly hazardous.
Petrol in a diesel: how does it occur?
Nobody does it on purpose, and it is rarely carelessness. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
Routine and the car falling out of step is when it occurs. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Filling up in a rush on the way to Wennington, with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
Next time you fill up in Kearstwick: avoiding petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on each forecourt. The label is what counts.
- Check your filler flap. Plenty of vehicles state the fuel type inside the flap or on the cap. Look at it on your first fill in any car you do not know.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key if a house has one of each. So label it.
- Say it before you lift it. On the 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.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Some diesels have a filler built 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 checking the petrol pump.
- Stop the moment you realise. Less petrol inside that tank makes a thinner mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Kearstwick?
Then, there is only a short order of things. Leave it unstarted, with the ignition off as well. Ask the staff to help you roll it away from the pump if you are still at the forecourt, whether that's Texaco or anywhere else. Next, 0333 366 0103. We'll ask what got in, about how much, and if it has been run.
If it was AdBlue instead of petrol, say so. That is a different fault — corrosion and deposits rather than lost lubrication — and it has its own page for Kearstwick.
Why one petrol in a diesel job in Kearstwick costs more than another
There's no fair single price for this, since the four situations above are four separate tasks. What shifts your cost is mostly which of them you are in. Where the vehicle is matters too, and whether a technician can safely get to it, after the ratio of petrol to what that tank takes.
Ahead of any quote, not after, come three questions: the fuel that got in, the volume, and if it has run. That is why. The replies turn a range into a straight figure.
About Kearstwick
Kearstwick is a small hamlet in Cumbria, situated inland at an elevation of 67 metres, and is located near the cities of Lancaster and Kirkby Lonsdale. Kearstwick has a population of around 516 people, and its housing stock is predominantly made up of detached homes. Kearstwick is part of a wider rural area, with nearby villages including High Biggins and Casterton. Kearstwick is approximately 213.7 miles from London, making it a relatively remote community in the North West of England.
Fuel drain cover across Cumbria, Kearstwick included
Petrol in diesel jobs in Kearstwick — part of the LA postcode area — go to vans that also cover the locations about it, Kirkby Lonsdale, High Biggins and Casterton among them. The car does not need to move to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Kearstwick: still at the petrol pump?
Then, you could not be in a better place. Keep it off. Ring.