Kelbrook: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, you can worry far less than you probably are. Petrol resting in a diesel tank does nothing to the engine till something draws it through the system — the ignition priming your pump, the starter, or driving itself. So the fair answer to the first query anyone in Kelbrook asks, "have I wrecked it?", is usually no. To keep the vehicle that way, phone Petrol in Diesel and leave the motor alone. Below, this page sets out what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the engine?
Passing through an engine, diesel is doing two things at the same time. It protects first, and only then does it burn. What stops the surfaces inside the high-pressure fuel pump and the fuel injectors from grinding against one another is the diesel flowing through them — they are made to very fine tolerances.
Poorly at the first, not at all at the second: that is petrol. It's runnier than diesel and strips away the protection the fuel system depends 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.
Combined, those make the shape of the trouble clear. Contact doesn't do the damage — movement does. All a tank with petrol in it amounts to is a fuel issue. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to your injectors further on.
How bad is petrol in a diesel? Four situations we see in Kelbrook
The best case there can be: filled up, never started. Only that tank has petrol in it, so the job is draining your tank and rinsing the system where the vehicle stands. This situation can only truly occur at a forecourt: anywhere else, your car got there by being driven.
The ignition turned on, or a short start. Your system has been bled, and so petrol has left your tank and reached your filter and your lines. That is generally still a simple job — a drain, a flush, and the fuel filter seen to.
Those few miles driven were the pump working on fuel diluted by petrol the whole way. Distance is only half of it; how hard it was driven matters just as much. Either way the work includes your tank, your lines, the fuel filter and fresh fuel through the entire system. Driving the kids to Kelbrook Primary School is one sort of trip. Getting as far as Bradford, under 25 miles away, makes a very different job — as does any miles on the M65, under 5 miles from Kelbrook, with the motor labouring hard the whole time.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is your engine signalling fuel that no longer runs like diesel. Stop wherever you are — the verge on Quernmore Drive, a lay-by, a side street — then leave it there. A vehicle stopped early very seldom has permanent damage, because the drain and the flush-through, which still come first, deal with it.
Kelbrook drivers and the petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a fuller tank, still the same mix. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
Myth: a modern diesel copes with a bit of petrol. If anything, the reverse. At higher pressure, through more precise components: that is how a current diesel handles its fuel, and so the protection counts more, not less.
"It starts, it drives, and so there is no harm" — the myth that catches more drivers than any other. Feed diesel to a petrol motor and it generally won't run, so the driver stops — and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Running is not the same as fine.
Myth: a two-stroke additive makes it safe to drive home. It was an old fix, supposed for another issue. None of what petrol thinned is put back by it — and afterwards, the tank still contains that petrol.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the fuel filter and lines, ready to go straight back through your pump at the next start. On top of that, petrol cleared into a can by the road is truly risky.
Why petrol in a diesel takes place at all
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it easy, and the error runs one way.
It happens when habit and the car stop matching. Any car that is new to you — hired, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps laid out differently. Filling up in a hurry en route to Colne, with a train to catch. Precisely the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel at your next fill-up around Kelbrook
- Green for unleaded and black for diesel is usual in the UK — but not on each forecourt. Go by the label on the pump, not the colour.
- Check the filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, for a household with one of each.
- Before the nozzle comes off the pump the first time you fill a hired or new vehicle, say "diesel" out loud. Silly, yes, but it works.
- Tuck your phone away. This is an easy mistake to make whilst you are thinking about something else.
- Add-on devices are available for cars without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside that tank means a weaker blend. It doesn't change what to do next, which is still not to start it.
Kelbrook: already put petrol in a diesel?
In that case, there's just a short order of things. Leave it unstarted, with your ignition off too. Yet on the forecourt, at Total or anywhere else? Ask the attendants to help you push the vehicle away from the petrol pump. What went in, roughly how much, and whether it has run: tell us that when you phone 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Kelbrook, since AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job around Kelbrook costs more than another
Four different tasks lie behind the four situations above — which is why there is no honest single price. Chiefly, the cost shifts with which one you are in. The share matters next, meaning how much of that tank is petrol, followed by the location of the vehicle and whether reaching it is safe for a van.
That's why our technicians ask three queries before costing instead of after: what was put in, how much, and if it has run. Their answers are what turn a range into one firm number.
About Kelbrook itself
Kelbrook is a small village in Lancashire, situated on the banks of a river at an elevation of 171 metres. Kelbrook has a mix of housing types, but predominantly features terraced homes, reflecting its historic development as a rural community. Kelbrook is located near other small villages such as Sough, North Holme, and Salterforth, and is approximately 17.7 miles from the city of Bradford. Kelbrook remains a quiet residential area with a population of around 621 people.
Fuel drain cover across Lancashire, Kelbrook included
Petrol in diesel calls in Kelbrook — part of the BB postcode area — go to vans that likewise cover the places around it, Sough, North Holme and Salterforth included. The car doesn't need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Still at the petrol pump around Kelbrook?
Then you're in the best place there can be. Keep it off. Call.