Should You Worry? Petrol in a Diesel Car in Greenlees
Not started? Then less worried than you likely feel. "Have I ruined it?" is the first question everyone around Greenlees asks, and the truthful answer is usually no, because petrol left in a diesel tank hurts nothing till it is dragged through the system — by ignition priming, by the starter, or by driving. Leave your engine off then phone Petrol in Diesel — that is how you keep it like that. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
What petrol in a diesel does to your engine
Passing through an engine, diesel does two things at once. Before it burns, it lubricates — then it burns. Extremely fine tolerances are built into the fuel injectors and your high-pressure pump, and just the diesel running through stops those surfaces grinding together.
Of those two tasks, petrol handles the first poorly and the second not at all. A pump running on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the lubrication your fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any clattering starts.
Put those together and the shape of the trouble is clear. Contact does not do the damage — movement does. A tank with petrol in it is a fuel fault. After the pump has been working on that petrol, a mechanical problem has started: anything shed by a pump that is wearing down is carried downstream to the fuel injectors with the fuel.
Four scenarios our technicians see in Greenlees: how serious is petrol in a diesel?
Fuelled up, never started. The best case there can be. Only that tank has petrol in it, and so the task is emptying the tank and purging the fuel system where the vehicle sits. This situation can only truly happen at a forecourt: anywhere else, the vehicle got there by being driven.
A moment's running, or just the ignition on. With your system primed, your lines and filter now contain petrol that has come from the tank. Drain, flush, deal with the fuel filter: still normally easy.
Driven a few miles. Now your pump has spent those miles labouring on thinned fuel. The work is the tank, your lines, the filter and fresh fuel through the whole circuit, and how hard the car was driven counts as much as how far. On the school run to the local primary school, the distance is small. Very different once more: a trip to Glasgow, under 5 miles away, or any distance on the M74, under 3 miles from Greenlees, where the engine kept labouring hard.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The motor is telling you your fuel is no longer acting like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on B759. The drain and flush still go first, and they take care of it: when a car is stopped soon, permanent damage is very uncommon.
What Greenlees drivers 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. Topping up takes out nothing; it gives you a bigger tank of the same mix. Percentage isn't how a diesel fuel system copes with petrol, however much that advice supposes.
Myth: a newer diesel copes with a bit of petrol. If anything, the opposite. A newer diesel runs its fuel through finer components at higher pressure, which makes the protection matter more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up most people than any other. Any petrol motor fed diesel normally won't run, so the motorist stops and the damage stops with them. While your pump wears, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Running isn't the same as fine.
Myth: a two-stroke additive lets you to drive home. It was an old workaround, supposed for another problem. The petrol is still inside your tank after that, and what it has weakened is not put back.
The next start sends petrol back round the pump out of your lines and the fuel filter, where some of that sits after the motor has run. That's why draining the tank yourself doesn't sort it — a myth. It's also really risky to drain petrol into a can at the kerbside.
Why petrol in a diesel happens at all
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it simple: the petrol nozzle is the narrower 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 car at all. So the error runs one way.
It takes place when habit and the vehicle stop matching. Any car that's new to you — hired, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. Fuelling up in a rush on the way to Kirkhill, with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it takes place. With rain, a call arriving, or a car full of children to deal with, the hand simply does what it has always done.
Avoiding petrol in a diesel next time you fill up in Greenlees
- Read the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on each forecourt. The label is what matters.
- The first fill in a new car is the time to check your filler flap — inside it, or on the cap, plenty of motors state the fuel they take.
- One of each in the home? Label your key to the diesel — a bright fob, a sticker — because meaning to remember isn't enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It seems silly and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away then keep your mind on the petrol pump.
- Add-on devices are available for motors without one, and some diesels are built with a filler that won't accept a petrol nozzle. Helpful — but a backstop at best, never a reason to stop checking the label.
- Stop the moment you notice. Less petrol in your tank makes a weaker blend. It does not change what to do next, which is still not to fire it up.
Petrol already in a diesel around Greenlees? Begin here
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. Yet on the forecourt, at the nearest petrol station or anywhere else? Ask the attendants to help you push it clear of the pump. Next, 0333 366 0103. We'll ask what went in, about how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That's a different issue — corrosion and deposits and not lost lubrication — and it has its own page for Greenlees.
One petrol in a diesel job around Greenlees costs more than another. Why?
There is no honest single price for this, since the four situations above are four different jobs. The situation itself does most of the work of moving the cost. The share counts next, meaning how much of the tank is petrol, followed by the location of the vehicle and whether getting to it is safe for a technician.
That is why we ask three questions before pricing instead of after: what went in, how much, and if it's run. Those answers are what change a range into one firm number.
About Greenlees
Greenlees is a village situated on the riverside in South Lanarkshire, with a mix of detached housing and other residential properties. Greenlees sits at an elevation of 97 metres, close to the nearby cities of Glasgow and the surrounding neighbourhoods of Whitlawburn, Vicarland, and Springhall. Greenlees is located approximately 4.7 miles from Glasgow, making it a commuter-friendly location. Greenlees has a population of around 2680 residents, who enjoy the scenic riverside setting.
Across South Lanarkshire and in Greenlees: fuel drain cover
Greenlees waits in the G postcode area, and our vans that answer petrol in diesel calls there work the locations around it as well — Whitlawburn, Vicarland and Springhall among them. The vehicle doesn't need to move to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump in Greenlees, right now?
In that case, you couldn't be in a better spot. Switched off it stays; then ring.