Kings Cliffe: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you likely feel. Until your ignition primes your pump, your starter cranks, or your car is driven, petrol in a diesel tank simply sits there and does nothing. Which makes the honest reply to the first Kings Cliffe question — "have I ruined it?" — normally no. To leave it like that, phone Petrol in Diesel and leave the motor switched off. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and ways to make sure you never repeat it.
Petrol in a diesel: what does it do to the engine?
Two jobs fall to diesel on its journey through a motor. Before it combusts, it protects — and then it combusts. Your high-pressure pump and your injectors are built to extremely fine gaps, and your diesel passing through them is what keeps those surfaces from grinding against one another.
The second task petrol doesn't do at all, and the first it does badly. It is runnier than diesel and removes the protection your fuel system rests on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
Combined, those leave the shape of the problem plain. Contact does not do the harm — movement does. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical problem starts.
How serious is petrol in a diesel? Four scenarios our engineers see in Kings Cliffe
The best case there is: filled up, never started. On a forecourt, and really only there, the petrol is still limited to your tank — because everywhere else your car was driven to get to it. The job is emptying and cleaning on the spot.
Started for a moment, or only your ignition on. With your system primed, the fuel lines and filter already hold petrol that came from the tank. That is generally still an easy job — a drain, a flush, and your filter dealt with.
Those few miles driven meant the pump labouring on fuel weakened by petrol the whole way. The work is the tank, the lines, the fuel filter and fresh fuel through the whole system, and how hard the car was driven counts as much as how far. Short trips, like the school run to Kings Cliffe Endowed Primary School, are one thing. Getting as far as Peterborough, under 15 miles away, makes a very different task — as does any miles on the Great North Road, under 10 miles from Kings Cliffe, with your engine labouring hard the whole time.
Driven on until it complained — rattling, smoke, a lumpy idle, a dead throttle. That is your motor telling you its fuel has stopped acting like diesel. Stop on the spot — on the verge on Bridge Street, at the kerb, down a side road — and don't move it. Long-term damage is very uncommon when a car is stopped soon, and the fuel drain and flush that still come first deal with it.
Kings Cliffe motorists and the petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. That advice supposes a diesel fuel system handles petrol by percentage. It does not.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that's how a newer diesel moves its fuel, so the lubrication counts more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools drivers. The motorist of a petrol engine fed diesel usually stops, because it will not run, and the harm stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. A running engine does not mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a separate issue. It doesn't put back what petrol has weakened, and that petrol is still in the tank afterwards.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol sits in your filter and lines, ready to go right back through the pump on the next start. Draining petrol into a can at the roadside is also genuinely hazardous.
How does petrol in a diesel happen?
It's rarely carelessness, and nobody does it on purpose. One way only, since of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol vehicle. That's how the forecourt makes it easy.
Routine and your car falling out of step is how it occurs. Courtesy car, hire car, or a car that is new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps arranged differently. A train to catch, and a rushed fill en route to Stamford. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Throw in a back seat full of kids, a phone call or rain, and habit takes over.
Kings Cliffe people: how to prevent petrol in a diesel next time
- The label is what counts, so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- Many vehicles state the fuel type inside your filler flap or on the cap, so check it on your first fill in any car you do not know.
- Mark the key. In a house 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", aloud, before you pick up the nozzle — each time a new or hired car gets its first tank. It sounds silly. It works.
- Mistakes like this are easy to make while your mind is on something else, so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop checking the pump.
- The moment you realise, stop: less petrol in the tank means a thinner mixture. What to do next doesn't change, though — still do not crank it.
Already put petrol in a diesel around Kings Cliffe?
The order of things is short, then. Never fire it up, and don't turn your ignition on. If you're still at the forecourt — BP or anywhere else — ask the attendants to help you push it away from the petrol pump. What went in, about how much, and whether it has run: tell us that when you phone 0333 366 0103.
Say so if it was AdBlue rather than petrol: it's a separate fault, with its own page for Kings Cliffe, since AdBlue brings corrosion and deposits rather than lost lubrication.
One petrol in a diesel task in Kings Cliffe costs more than another. Why?
An honest single quote doesn't exist here: four situations, four separate tasks. Chiefly, your cost shifts with which one you're in. After that it's the share — how much petrol went in against how much that tank takes — and after that where your car is and whether a technician can reach it safely.
What got in, how much, and whether it has run — three questions our engineers ask before pricing, not after, for exactly that reason. A range turns into a straight figure when the answers are in.
About Kings Cliffe
Kings Cliffe is a village situated on the banks of the River Nene in Northamptonshire, with a mix of old and new buildings, including many detached homes. Kings Cliffe has a population of around 1043 people and is located near the villages of Apethorpe and Woodnewton. Kings Cliffe sits at an elevation of approximately 50 metres above sea level, close to the Cambridgeshire border. Kings Cliffe is within commuting distance of Peterborough, which is about 11.5 miles away.
Across Northamptonshire and around Kings Cliffe: fuel drain cover
Petrol in diesel calls around Kings Cliffe — part of the PE postcode area — go to vans that also cover the locations round it, Apethorpe, Woodnewton and Fineshade included. You need not move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
In Kings Cliffe and still at the pump?
Then you are in the best place there is. Call, and keep it turned off.