Petrol in a Diesel Car in Middleton Park: How Worried Should You Be?
Likely less than you already are — as long as nobody has started it. Everyone around Middleton Park begins with "have I wrecked it?", and the fair answer is usually no: petrol resting inside your tank of any diesel remains harmless until priming, cranking or driving draws it into your fuel system. Petrol in Diesel is who to call, with your engine left off, and so it remains that way. What petrol really does to a diesel, how to judge how far it's travelled, and how to keep it from happening a second time: that is the remainder of this page.
What petrol in a diesel does to your engine
Two tasks fall to diesel on its journey through a motor. It ignites, and before it burns it lubricates. Very fine clearances go into the injectors and the high-pressure pump, and just your diesel flowing through keeps their surfaces from grinding together.
Petrol does the first job badly and the second not at all. The knocking comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the fuel system rests on, and any pump running on such a blend is wearing itself.
Together, those leave the shape of the trouble clear. The damage is done by movement, not by contact. A tank with petrol in it is a fuel issue. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors further along, which is why a pump that has been working on that petrol is where a mechanical fault begins.
Petrol in a diesel in Middleton Park: how serious is it? Four situations
Filled up, not once started. The best case there can be. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol kept in that tank alone, it's drained and purged right where it stands, and nothing more is needed.
Ignition on, or started for a moment. With your system primed, the lines and filter already contain petrol that has come from the tank. Still normally simple: drain, flush, and the fuel filter seen to.
A few miles driven, and the pump has spent each of them working on thinned fuel. Tank, lines, filter, then clean fuel run through the entire system: that's this work, and the way the vehicle was driven counts as much as the miles. Driving the kids to the local primary school is one sort of trip. Any mileage on the M90, over 50 miles from Middleton Park, means the motor has worked hard throughout, and a run to Aberdeen, under 5 miles away, is a very different task too.
Driven till it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and the motor is saying so. Whether it is the verge on Middleton Road, a lay-by or a side street, stop there and leave it. A car pulled over early very seldom has permanent damage, as the drain and the flush-through, which still go first, take care of it.
What Middleton Park drivers get told about petrol in a diesel — and the myths 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. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. A newer diesel sends its fuel through finer components at higher pressure, which makes the protection count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no damage done." Feed diesel to a petrol motor and it usually won't run, so the driver stops — and the damage stops with them. Feed petrol to a diesel and it usually starts, idles and drives away like nothing happened — all while its pump wears. Running is not the same as fine.
An outdated fix for a different problem is behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has weakened remains weakened, and that petrol remains inside your tank regardless.
Once the engine has been run, part of the petrol is in the filter and your lines, not your tank — and the next start sends it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not stand up. It is also really hazardous to drain petrol into a can at the kerbside.
How petrol ends up: petrol in a diesel
It is seldom carelessness, and no one does it on purpose. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly won't go into a petrol motor at all. So the error runs one way.
It takes place when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the drive. A forecourt you know, but with its pumps laid out differently. Filling up in a rush on the way to Dyce, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. Throw in a back seat full of kids, a phone call or rain, and the hand takes over.
Next time you fill up around Middleton Park: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Read the petrol pump's label; the colour is just a hint.
- Check the filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in a car you do not know.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key if a home has one of each. So label it.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" aloud. Daft, yes, but it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the petrol pump.
- Noticing it halfway? Stop there and then. A weaker blend results from less petrol in your tank, but your next step remains the same: don't crank it.
Middleton Park: already put petrol in a diesel?
In that case, there's only a short order of things. Never crank it, and don't turn your ignition on. Yet at the forecourt, at Asda or anywhere else? Ask the staff to help you push the vehicle away from the pump. Then phone 0333 366 0103 and tell us what was put in, about how much, and whether it's run.
If it was AdBlue instead of petrol, say so. That is a separate fault — corrosion and deposits rather than lost lubrication — and it has its own page for Middleton Park.
What makes one Middleton Park petrol in a diesel task cost more than the next
The four situations above are four separate jobs, so no single price for this would be fair. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a share of what that tank takes, then the spot your car is in and whether a van can get to it safely.
What was put in, how much, and whether it has run — three queries we ask before quoting, not after, for precisely that reason. The replies turn a range into a straight figure.
About Middleton Park
Middleton Park is a suburban area in Aberdeen City, situated approximately 3 miles north of Aberdeen's city centre. Middleton Park sits on the coastal fringe of the city, with its residential streets and semi-detached housing stock laid out at an elevation of around 88 metres. Middleton Park is bordered by other suburban areas, including Danestone and Denmore, and is part of the larger Aberdeen urban area. Middleton Park has a population of around 5667 people, according to recent estimates.
Middleton Park and Aberdeen City: where our fuel drain cover runs
Danestone, Denmore and Bridge of Don are among the places near Middleton Park that the same teams work, answering petrol in diesel calls across Middleton Park's AB postcode area. The car doesn't need to come to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the pump around Middleton Park?
No position is better: that is where you now are. Call, and leave it switched off.