The Hale: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, if it hasn't been started. Until your ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank simply rests there and does no harm. Which makes the truthful reply to that first The Hale question — "have I wrecked it?" — normally no. Petrol in Diesel is who to call, with your engine kept off, and so it remains that way. What petrol actually does to a diesel, how to gauge how far it has gone, and how to keep it from happening a second time: that is the remainder of this page.
Your engine and petrol in a diesel: what goes on
Passing through a motor, diesel does two things at once. It protects first, and only then does it burn. Designed to extremely fine clearances, the injectors and your pump depend on the diesel moving through them to keep their surfaces from wearing against one another.
Of those two tasks, petrol manages the first badly and the second not at all. The clattering 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 protection the fuel system depends on, and any pump running on that mix is wearing itself.
Taken together, they show the shape the trouble has. Contact doesn't do the damage — circulation does. A tank with petrol in it is a fuel fault. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with your fuel to the injectors beyond it.
Petrol in a diesel around The Hale: how serious is it? Four situations
Filled up, and not started: no case is better. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol kept in your tank alone, it's emptied and flushed right where it stands, and nothing more is needed.
Started for a second, or only your ignition on. The system has been primed, and so petrol has left the tank and got to your filter and the fuel lines. Normally little more than clearing, cleaning and sorting your filter, and so still straightforward.
The pump now worked a few miles on thinned fuel — that is what driving the vehicle meant. Tank, lines, filter, then fresh fuel put through the entire system: that's the work, and the way the vehicle was driven counts as much as the miles. Driving the kids to Mathilda Marks-Kennedy Jewish Primary School is one sort of trip. Driving as far as St Albans, under 10 miles away, makes a very different task — as does any distance on the M1, under a mile from The Hale, with the motor running hard all the way.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That's the engine telling you its fuel no longer is behaving like diesel. Whether it is the verge on Stoneyfields Gardens, a lay-by or a side road, stop where you are and leave it. The fuel drain and flush-through still come first, and they sort it out: when a vehicle is stopped early, permanent damage is very uncommon.
Myths The Hale people hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed when you top up — that tank simply holds more of the same blend. The idea behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. A current diesel runs its fuel through finer parts at higher pressure, which makes the protection count more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more motorists than any other. The motorist of a petrol engine fed diesel normally has no choice but to stop, since it will not run, and the damage stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile your pump wears. Fine and running are not the same thing.
Not so: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another fault. The petrol is still inside your tank afterwards, and whatever it has diluted is not put back.
The next start draws petrol back round the pump out of the fuel lines and the filter, where some of it ends up after the engine has run. That's why a DIY tank drain does not leave you sorted — a myth. Besides, petrol emptied into a can by the road is genuinely risky.
Why petrol in a diesel occurs so easily
Nobody does it on purpose, and it is rarely carelessness. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol car at all. So the slip runs one way.
It takes place when habit and your car stop matching. A vehicle that is new to you — hired, on loan as a courtesy car, or brand new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. Filling up in a rush en route to Mill Hill Broadway, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: exactly when it occurs. Throw in a back seat full of children, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up around The Hale
- The label is what matters, and so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- In a motor you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles print the fuel there.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of meaning to remember, for a household with one of each.
- It sounds silly and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Put the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Some diesels come with a filler designed to block a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- The moment you notice, stop: less petrol in the tank makes a weaker mixture. What to do next does not change, though — still do not crank it.
Already put petrol in a diesel around The Hale?
Then the order of things is brief. Starting it is out, and so is turning on your ignition. The attendants on the forecourt — whether at Texaco itself or wherever you filled up — will normally help push it away from the petrol pump if you ask. Phone 0333 366 0103 next, with three facts — the fuel, the approximate quantity, and whether it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate fault — The Hale has a page just for it.
One petrol in a diesel task around The Hale costs more than another. Why?
Four different tasks sit behind the four situations above — which is why there is no fair single price. Which of them you're in is mostly what moves the cost. The ratio matters next, meaning how much of that tank is petrol, and then the position of your car and whether getting to it is safe for a van.
Three questions come first, before quoting, rather than after — what went in, how much, has it run — and this is the reason. Their replies are what turn a range into one firm number.
About The Hale itself
The Hale is a suburban area in northwest London, situated near the River Brent and close to several neighbouring communities, including Edgware and Burnt Oak. The Hale sits at an elevation of around 74 metres, with semi-detached housing being the predominant type of accommodation in the area. The Hale is located approximately 9.6 miles from central London, making it a commuter-friendly location for those working in the city. The Hale is also near Highwood Hill, which offers scenic views of the surrounding area.
Across Greater London and in The Hale: fuel drain cover
Our teams answering petrol in diesel calls in The Hale, in the HA postcode area, also work the locations around it, Edgware, Burnt Oak and Highwood Hill included. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians drain, and the vehicle doesn't need to move to us.
At the pump in The Hale, still?
In that case, you couldn't be in a better place. Switched off it remains; then ring.