Should You Worry? Petrol in a Diesel Car in Cheeklaw
Provided it hasn't been started, you can worry far less than you probably are. Everyone in Cheeklaw begins with "have I wrecked it?", and the honest answer is usually no: petrol resting in your tank of a diesel remains harmless till priming, cranking or driving draws it into the fuel system. To leave the car that way, phone Petrol in Diesel and leave your engine alone. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never repeat it.
What petrol in a diesel does to the engine
Diesel has two jobs on its way through a motor. Before it ignites, it protects — and then it ignites. Very fine clearances go into your injectors and the high-pressure pump, and just the diesel flowing through stops those surfaces grinding together.
Petrol does the first job poorly and the second not at all. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump running on that mixture to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
Combined, those leave the shape of the trouble clear. The damage is done by movement, not by contact. Petrol in a tank is a fuel issue. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
Cheeklaw, petrol in a diesel: four situations, from mild to serious
Fuelled, and never started: nothing beats it. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With the petrol kept in the tank alone, it is drained and purged right where it stands, and nothing more is needed.
Started for a moment, or just the ignition on. Petrol has come out of the tank and got to your filter and the fuel lines, since the system has been bled. That is usually still a straightforward job — a drain, a flush, and the filter seen to.
Driven a few miles. Now your pump has spent those miles running on diluted fuel. Miles is only half of it; how hard it was driven matters just as much. Either way this work runs to your tank, the lines, the filter and fresh fuel through the entire circuit. Driving the kids to the local primary school is one sort of trip. Very different again: a trip to Edinburgh, under 50 miles away, or some mileage on the M8, under 50 miles from Cheeklaw, where the engine never stopped working hard.
Driven until it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and your motor is telling you. Pull up wherever you are — the verge on A6112, a lay-by, a side street — and leave the vehicle where it is. The fuel drain and flush still go first, and they sort it out: when a vehicle is pulled over soon, long-term damage is very unusual.
Cheeklaw motorists and that petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. A diesel fuel system does not tolerate petrol by percentage in the way that advice supposes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. Protection matters more on current diesels, not less, since their fuel passes through smaller parts at higher pressure.
"It starts, it drives, so no harm done" — the myth that trips up most people than any other. Any petrol motor fed diesel normally won't run, and so the driver stops and the harm stops with them. While the pump wears, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a distinct problem. That petrol is still in the tank after that, and whatever it has thinned is not put back.
If the motor has been run, part of the petrol is in your filter and the fuel lines, not that tank — and your next start pulls it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not stand up. Draining petrol into a can by the kerbside is also genuinely risky.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol motor. That is how the forecourt makes it easy.
It takes place when habit and the vehicle stop matching. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Filling up in a hurry en route to Reston, with a train to catch. A new-to-you diesel Renault Clio, its first fuelling, and a motorist accustomed to petrol: precisely when it happens. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
How to avoid petrol in a diesel on your next fill-up around Cheeklaw
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what matters.
- Plenty of cars state the fuel type inside your filler flap or on the cap, and so check it on the first fill in a vehicle you do not know.
- Label your key. In a house 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 pump the first time you fuel a hired or new car, say "diesel" aloud. Daft, perhaps, yet it works.
- Put your phone away. This is an easy mistake to make while you are thinking about something else.
- Some diesels come with a filler built to block a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Stop the moment you notice. Less petrol in your tank makes a weaker mixture. It doesn't change what to do next, which is still not to crank it.
Put petrol in a diesel around Cheeklaw already?
Then, there is just a short order of things. Leave it unstarted, with your ignition off too. Ask the staff to help you roll it clear of the pump if you're still at the forecourt, whether that's Gulf or somewhere else. Next, 0333 366 0103. We will ask what was put in, about how much, and if it's been run.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and read its own Cheeklaw page.
Cheeklaw petrol in a diesel jobs: why one costs more than another
A fair single price doesn't exist here: four situations, four separate jobs. The scenario itself does most of the work of moving your cost. Where your car is matters too, and whether a technician can safely reach it, after the share of petrol to what that tank takes.
What was put in, how much, and whether it has run — three queries we ask before pricing, not after, for exactly that reason. Given those answers, you get a straight figure instead of a range.
About Cheeklaw, briefly
Cheeklaw is a suburban area in the Scottish Borders, situated inland at an elevation of 119 metres. Cheeklaw lies near the towns of Duns and Buxley, and is close to the Wellnage Myre area. Cheeklaw has a population of around 1123 people, predominantly living in semi-detached housing. Cheeklaw is located approximately 35 miles from Edinburgh, the nearest city.
Fuel drain cover in Cheeklaw and across Scottish Borders
Cheeklaw sits in the TD postcode area, and our teams that answer petrol in diesel jobs there work the spots around it as well — Wellnage Myre, Duns and Buxley among them. The car does not need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Cheeklaw and still at the pump?
No position is better: that is where you now are. Keep it off. Phone.