Should You Worry? Petrol in a Diesel Car in Camelsdale
Unstarted? Then less worried than you probably are. "Have I ruined it?" is the first thing everyone around Camelsdale asks, and the honest answer is normally no, because petrol left in a diesel tank harms nothing until it's drawn through the fuel system — by ignition priming, by your starter, or by driving. Leave the motor off then call Petrol in Diesel — that is how you keep it that way. The rest of this page covers what petrol really does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
Inside your engine: what petrol in a diesel really does
On its way through a motor, diesel does two jobs. Lubricating comes before burning; it does both. The high-pressure fuel pump and your injectors are designed to extremely fine tolerances, and the diesel passing through them is what keeps those surfaces from grinding against one another.
Badly at the first, not at all at the second: that's petrol. A pump running on a petrol mix is wearing itself out, because petrol is runnier than diesel and takes away the protection your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where any knocking comes.
Taken together, they make clear what shape the issue has. Not contact but circulation is what does the damage. Petrol in a tank is a fuel issue. The beginning of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the injectors beyond it.
Four situations our technicians see around Camelsdale: how serious is petrol in a diesel?
The best case there is: filled up, never started. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held inside your tank alone, it is drained and rinsed on the spot, and nothing more is needed.
A moment's running, or merely your ignition on. Petrol has left your tank and got to the filter and the lines, because your system has been primed. That's usually still a straightforward task — a drain, a flush, and the filter seen to.
Driven a few miles. Now your pump has spent those miles working on diluted fuel. Tank, lines, filter, then clean fuel put through the whole system: that's the work, and the way your car was driven counts as much as the mileage. A school run to Camelsdale Primary School is one matter. Driving as far as Chichester, under 25 miles away, makes a very different job — as does any miles on the M3, under 25 miles from Camelsdale, with your engine running hard the whole time.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone lumpy. That's the engine telling you its fuel has stopped behaving like diesel. Whether it's the verge on Upper School Drive, a lay-by or a side street, stop where you are and leave it. A car stopped early very seldom has lasting damage, since the drain and the flush, which still come first, sort it out.
What Camelsdale drivers get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. A bigger tank of the same mixture is all it gives, since topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that guidance presumes.
If anything, the reverse holds. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through more precise parts: that is how a modern diesel moves its fuel, and so the protection counts more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more motorists than any other. Any petrol motor fed diesel usually won't run, and so the motorist stops and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile your pump grinds. Being able to run isn't the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different problem. It doesn't put back what petrol has weakened, and that petrol is still inside your tank later on.
Once the motor has been run, part of the petrol is in the fuel filter and your lines, not your tank — and your next start pulls it right back through your pump. So the myth "drain that tank yourself and you're sorted" doesn't hold. On top of that, petrol drained into a can by the road is genuinely risky.
Petrol in a diesel: how does it take place?
No one does it on purpose, and it is seldom carelessness. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it simple, and the slip runs one way.
When habit and your car stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. Fuelling up in a rush en route to Haslemere, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: exactly when it happens. With rain, a call coming in, or children to deal with, your hand simply does what it always has.
Camelsdale people: how to prevent petrol in a diesel next time
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on each forecourt. The label is what matters.
- The first fill in an unfamiliar vehicle is the time to check your filler flap — inside it, or on the cap, many cars state the fuel to use.
- Label your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car gets its first tank. It seems daft. It does the trick.
- While you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Some diesels come with a filler designed to block 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 checking the petrol pump.
- Noticing it halfway? Stop there and then. A weaker blend results from less petrol inside the tank, yet the next stage remains the same: do not crank it.
Camelsdale: already put petrol in a diesel?
The order of things is brief, then. Starting it is out, and so is switching on the ignition. Still at the forecourt, at Arnolds Garage or anywhere else? Ask the staff to help you push the vehicle away from the pump. What went in, about how much, and if it's run: tell us those when you ring 0333 366 0103.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Camelsdale page.
One petrol in a diesel job around Camelsdale costs more than another. Why?
There's no fair single price for this, since the four situations above are four different tasks. Which of them you are in is mostly what moves the cost. The share counts next, meaning how much of the tank is petrol, and then the position of the car and whether reaching it is safe for a technician.
That is why we ask three questions before costing rather than after: what was put in, how much, and if it's run. Their replies are what turn a range into one firm number.
About Camelsdale
Camelsdale is a suburban area situated on the riverside in West Sussex, with an elevation of around 136 metres. Camelsdale lies near the villages of Shottermill and Critchmere, and is close to the settlement of Hammer. Camelsdale has a population of approximately 2465 people, predominantly living in detached housing.
Camelsdale and West Sussex: where our fuel drain cover reaches
Shottermill, Critchmere and Hammer are among the places around Camelsdale that the same vans work, answering petrol in diesel jobs across Camelsdale's GU postcode area. You need not move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
In Camelsdale and still at the petrol pump?
Then you're in the best position there is. Turned off it remains; then phone.