Rutherglen: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry far less than you probably are. "Have I ruined it?" is the first thing anyone around Rutherglen asks, and the honest answer is normally no, because petrol left in a diesel tank harms nothing till it is dragged through the system — by ignition priming, by your starter, or by being driven. Keep it like that: leave your motor off then call Petrol in Diesel. Further down, 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.
What petrol in a diesel does to your engine
Diesel does two tasks on its way through a motor. Before it ignites, it lubricates — and then it ignites. Built to very fine gaps, the fuel injectors and your pump rely on your diesel moving through them to stop their surfaces wearing against one another.
The second job petrol doesn't do at all, and the first it does badly. A pump running on a petrol mix is wearing itself out, because petrol is thinner than diesel and strips out the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where any clattering comes.
The shape of the problem is plain when you put those together. It's movement that causes the damage, not contact. Where that petrol is only in that tank, it's a problem of fuel, nothing more. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors further on.
Rutherglen, petrol in a diesel: four situations, from mild to major
Filled up, and not started: nothing beats it. Just the tank has petrol in it, and so the task is clearing your tank and rinsing your system where your car sits. This situation can only really take place on a forecourt: anywhere else, the car got there by being driven.
Started for a moment, or only the ignition on. Your system has been primed, and so petrol has left your tank and got to the filter and the fuel lines. Usually nothing more than clearing, rinsing and seeing to your filter, and so still easy.
Driven a few miles. Now the pump has spent those miles running on diluted fuel. How hard the vehicle was driven counts as much as how far, and the work takes in the tank, your lines, the fuel filter and fresh fuel through the whole circuit. The school run to the local primary school is one matter. Any mileage on the M74, under a mile from Rutherglen, means your engine working hard throughout, and a run to Glasgow, under 3 miles away, is a very different job too.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone lumpy. That is the motor telling you its fuel no longer is acting like diesel. Whether it's the verge on Castle Street, a lay-by or a side street, stop where you are and leave it. A vehicle pulled over early very seldom has long-term damage, as the drain and the flush, which still come first, deal with it.
What Rutherglen people get told about petrol in a diesel — and the stories in it
False: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. At higher pressure, through finer parts: that's how a modern diesel moves its fuel, and so the protection matters for more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that won't run: the driver stops, and so does the damage. Feed petrol to a diesel and it usually starts, ticks over and pulls away as if nothing has happened — all while its pump wears. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive it home." It's an old workaround for a separate issue. It does not put back what petrol has diluted, and the petrol is still inside the tank afterwards.
Once the engine has been run, part of the petrol sits in the fuel filter and the lines, not your tank — and the next start sends it straight back through your pump. So the myth "drain that tank yourself and you are sorted" does not hold. It is also really hazardous to drain petrol into a can at the kerbside.
Why petrol in a diesel occurs at all
Carelessness is seldom the cause, and no one means to do it. A diesel nozzle generally won't go into a petrol car, but the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and just in one direction.
Routine and the car getting out of step is when it takes place. A vehicle that is new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the driveway of the same household. A familiar forecourt with the pumps in a different order. Rushing for a train outside the nearest station and fuelling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. With rain, a call coming in, or a car full of children to deal with, the hand just does what it always has.
Next time you fill up in Rutherglen: avoiding petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the petrol pump's label; the colour is only a clue.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before the first fill: many motors print the fuel there.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a house has one of each. So mark it.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It seems daft and it works.
- Whilst you are thinking about something else, this is an easy mistake to make — so put your phone away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and aftermarket devices are available for the rest. Treat it as a safety net, and keep checking the petrol pump.
- Stop as soon as you notice. Less petrol in your tank means a weaker mix. It doesn't change what to do next, which is still not to crank it.
Petrol already in a diesel around Rutherglen? Begin here
Then the order of things is brief. Leave it unstarted, with your ignition switched off too. The staff on the forecourt — whether at BP itself or wherever you filled up — will usually help push it clear of the pump if you ask. What got in, about how much, and whether it's run: tell us that when you ring 0333 366 0103.
Corrosion and deposits are the problem with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own Rutherglen page.
Why one petrol in a diesel job in Rutherglen costs more than another
The four scenarios above are four different jobs, so no single price for this would be fair. Mostly, the cost moves with which situation you are in. The proportion matters next, meaning how much of that tank is petrol, and then the location of the vehicle and whether getting to it is safe for our van.
Ahead of any quote, not after, we ask three questions: your fuel that got in, the volume, and if it has run. That's why. With those answers, you get a straight figure rather than a range.
About Rutherglen
Rutherglen is a town situated on the south bank of the River Clyde in South Lanarkshire, with a mix of flat and other types of housing. Rutherglen lies close to Glasgow, Scotland's largest city, and is connected to it by several main roads. Rutherglen has a population of around 23,400 people and is near several smaller communities, including Gallowflat and Farm Cross. Rutherglen is relatively low-lying, with an average elevation of 24 metres above sea level.
Fuel drain cover across South Lanarkshire, Rutherglen included
Rutherglen waits in the G postcode area, and our vans that answer petrol in diesel jobs there work the locations around it as well — Gallowflat, Farm Cross and Bankhead among them. Our engineers drain where the vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Rutherglen and still at the pump?
The best position there is, then — that is where you are. Ring, and keep it turned off.