How Worried Should You Be? Petrol in a Diesel Car in Wootton
Far less than you likely are, if it has not been started. "Have I ruined it?" is the first question anyone in Wootton asks, and the truthful answer is usually no, because petrol resting in a diesel tank harms nothing till it's dragged through the fuel system — by ignition priming, by the starter, or by driving. Petrol in Diesel is who to call, with the motor left off, and so it stays that way. 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 doesn't happen to you again.
What petrol in a diesel does to the motor
Two tasks fall to diesel on its route round a motor. It burns, and before it burns it protects. What stops the surfaces inside the high-pressure pump and the fuel injectors from grinding against each other is your diesel passing through them — they're designed to very fine tolerances.
Of those two jobs, petrol handles the first badly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump on the blend to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the clattering.
Put those together and the shape of the issue is clear. The damage is done by circulation, not by contact. Where that petrol is only in the tank, it is an issue of fuel, nothing more. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to your injectors downstream.
Petrol in a diesel around Wootton: how serious is it? Four cases
Filled but never started — the best it gets. Being at a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With that petrol held in your tank alone, it is emptied and purged right where it stands, and nothing more is needed.
A moment's running, or merely the ignition on. With your system primed, the lines and filter already contain petrol that came from that tank. Drain, flush, deal with your filter: still normally simple.
Those few miles driven were your pump running on fuel weakened by petrol the whole way. Miles is only half of it; how hard it was driven matters equally. Either way the work includes your tank, the fuel lines, the filter and clean fuel through the entire system. The school run to Wootton St Peter's Church of England Primary School is one matter. Getting as far as Oxford, under 5 miles away, makes a very different task — as does any distance on the Wheatley Spur, under 10 miles from Wootton, with the motor working hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. That's your engine telling you its fuel has stopped behaving like diesel. Whether it is the verge on Cumnor Road, a lay-by or a side road, stop there then leave it. What comes first is still the drain and flush-through, and that deals with it, with long-term damage very rare if a car is stopped quickly.
Myths Wootton people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. Percentage is not how a diesel fuel system copes with petrol, however much that advice assumes.
"Modern diesels can handle a little petrol" — a myth, and closer to the opposite. Finer components and higher pressure are how a newer diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." Feed diesel to a petrol engine and it normally won't run, so the motorist stops — and the damage stops with them. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, while the pump wears. Fine and running are not the same thing.
Myth: "Add some two-stroke oil and drive it home." It's an old fix for a separate fault. The petrol is still inside your tank after that, and whatever it has thinned is not put back.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in the fuel filter and lines, waiting to go right back through the pump at your next start. It's also really risky to drain petrol into a can at the roadside.
Petrol in a diesel: how does it occur?
It's seldom carelessness, and no one does it on purpose. A diesel nozzle mostly won't fit a petrol vehicle, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake easy, and only in one direction.
Habit and your car getting out of step is when it occurs. A motor that is new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the driveway. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill en route to Radley. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. The hand does what it has always done once you add rain, a phone call or a back seat full of children.
Wootton people: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Go by the label on the pump, not the colour.
- The first fill in a strange vehicle is the time to check your filler flap — on it, or on the cap, many motors state which fuel to use.
- One of each in the home? Label your key to the diesel — a coloured fob, a sticker — because meaning to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds silly. It does the trick.
- Mistakes like this are easy to make whilst your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a backstop, then keep reading the petrol pump.
- Stop the moment you notice. Less petrol inside your tank makes a weaker mixture. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Wootton?
In that case, there's just a short order of things. Don't start the car, and do not switch the ignition on. The attendants on the forecourt — whether at Marcham Road Service Station itself or wherever you filled up — will normally help roll it away from the pump if you ask. Then call 0333 366 0103 and tell us what was put in, roughly how much, and whether it's run.
If it was AdBlue instead of petrol, say so. That is a separate problem — corrosion and deposits rather than lost lubrication — and it has its own page for Wootton.
One petrol in a diesel task around Wootton costs more than another. Why?
An honest single price doesn't exist here: four situations, four separate tasks. What moves your cost is mostly which of them you're in. Two things follow that: the petrol that went in as a proportion of what the tank takes, then the spot the car is in and whether a technician can get to it safely.
That is why we ask three queries before costing rather than after: what was put in, how much, and if it's run. Given those replies, there is a straight figure rather than a range.
About Wootton, briefly
Wootton is a village in Oxfordshire, situated on the banks of the River Ock at an elevation of around 96 metres. Wootton lies close to the city of Oxford, approximately 4 miles to the west, and is part of the wider South East region. Wootton has a mix of housing types, but detached homes are particularly prevalent in the area. Wootton is also near to other small settlements, including Henwood and Dry Sandford.
Wootton and Oxfordshire: where our fuel drain cover runs
The vans answering petrol in diesel jobs in Wootton, in the OX postcode area, also work the spots around it, Wootton Village, Henwood and Dry Sandford among them. No need to move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Still at the petrol pump around Wootton?
Then you are in the best place there is. Call, and leave it switched off.