Petrol in a Diesel Car in New Quarrington: How Worried Should You Be?
Not started? Then less worried than you probably feel. Till the ignition primes your pump, the starter turns, or your car is driven, petrol in a diesel tank just rests there and does nothing. Which means the truthful reply to that first New Quarrington query — "have I wrecked it?" — usually no. Keep it like that: leave your engine off then call Petrol in Diesel. The remainder of this page covers 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 a second time.
Inside your engine: what petrol in a diesel does
Diesel does two jobs on its way through an engine. It protects to begin with, and after that does it burn. What keeps the surfaces inside your high-pressure pump and the injectors from grinding against each other is the diesel flowing through them — they are made to extremely fine clearances.
Of those two jobs, petrol manages the first badly and the second never. It is thinner than diesel and strips away the lubrication the system depends on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the knocking comes from.
Put these together and the shape of the trouble is plain. The harm is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel fault. After your pump has been working on that petrol, a mechanical problem has begun: anything shed by a pump that is wearing travels downstream to the fuel injectors with the fuel.
Petrol in a diesel in New Quarrington: how bad is it? Four situations
The best case there is: filled up, never started. The petrol is inside your tank and only that tank, and the task is a drain and a flush where the car sits. This is the one scenario that can only really occur at a forecourt, because anywhere else your car has been driven to get there.
Started for a second, or only your ignition on. With the system primed, the fuel lines and filter now contain petrol that has come from your tank. That's generally still a straightforward job — a drain, a flush, and the filter dealt with.
Driven a few miles. Now the pump has spent those miles labouring on thinned fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's the work, and the way your car was driven counts as much as the distance. Short trips, like the school run to St Botolph's C of E Primary School, are one thing. Any mileage on the Great North Road, under 50 miles from New Quarrington, means the engine working hard throughout, and a run to Lincoln, under 25 miles away, is a very different job as well.
Driven till it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and your engine is telling you. Stop on the spot — on the verge on Northfield Road, at the kerb, down a side road — and do not move it. What comes first is still the drain and flush, and that deals with it, with lasting damage very unusual if a car is pulled over early.
Myths New Quarrington motorists hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through finer components: that is how a modern diesel moves its fuel, so the protection counts for more, not less.
This is the one that fools people. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor normally means a motor that will not run: the driver stops, and so does the harm. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile your pump wears. Running does not mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated fix for a distinct issue. The petrol is still in that tank afterwards, and whatever it has diluted is not put back.
The next start sends petrol back round your pump from the fuel lines and the fuel filter, where some of that ends up after your engine has run. That's why a DIY tank drain doesn't sort it — a myth. Draining petrol into a can by the roadside is also genuinely dangerous.
Why petrol in a diesel occurs so easily
Carelessness is seldom the cause, and nobody means to do it. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
The moment habit stops matching your car is the moment it happens. Hire cars, courtesy cars, and vehicles that are new to you. Households running one of each, petrol and diesel. Your ordinary forecourt, its pumps suddenly in a different order. Filling up in a rush en route to Sleaford, with a train to catch. Years of petrol motors behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that's when. With rain, a call arriving, or children to deal with, your hand just does what it always has.
How to prevent petrol in a diesel on your next fill-up in New Quarrington
- The label is what counts, and so check the petrol pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on every forecourt.
- Many motors state the fuel inside your filler flap or on the cap, and so check there on your first fill in a vehicle you don't know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a house with one of each.
- Before the nozzle comes off the pump the first time you fill a hired or new vehicle, say "diesel" out loud. Daft, yes, yet it does the trick.
- Put the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and aftermarket devices exist for the remainder. Count it as a safety net, then keep reading the pump.
- Noticing it halfway? Stop at once. A weaker blend follows from less petrol inside that tank, but your next stage stays the same: do not fire it up.
Petrol already in a diesel in New Quarrington? Begin here
In that case, there's just a short order of things. Starting it is out, and so is switching on your ignition. Ask the attendants to help you roll it clear of the petrol pump if you are still on the forecourt, whether that is Murco or somewhere else. What went in, about how much, and whether it has run: tell us that when you phone 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a different problem — New Quarrington has a page just for it.
One petrol in a diesel job around New Quarrington costs more than another. Why?
There's no fair single quote for this, since the four scenarios above are four separate tasks. What shifts the cost is mostly which of them you're in. Two things come after that: the petrol that got in as a proportion of what your tank holds, then the place the car is in and whether a van can get to it safely.
Before any quote, not after, we ask three questions: the fuel that went in, its amount, and if it's run. That's why. A range turns into a straight figure once those replies are in.
About New Quarrington
New Quarrington is a suburban area situated on the riverside in Lincolnshire, with a relatively low elevation of 31 metres. New Quarrington lies near the city of Lincoln, approximately 17 miles to the south, and is close to nearby places such as Quarrington and Sleaford. New Quarrington has a population of around 2634 people, predominantly living in detached housing. New Quarrington is also within a reasonable distance from London, at around 103 miles away.
New Quarrington and Lincolnshire: where our fuel drain cover reaches
New Quarrington waits in the NG postcode area, and the teams that answer petrol in diesel call-outs there work the spots around it as well — Quarrington, Sleaford and Greylees 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 driveway.
In New Quarrington and still at the petrol pump?
Nothing beats it: that's where you are. Turned off it remains; then phone.