Burnham: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, worry far less than you likely are. "Have I wrecked it?" is the first thing anyone in Burnham asks, and the honest answer is usually no, since petrol resting in a diesel tank hurts nothing till it is dragged through the system — by ignition priming, by your starter, or by being driven. To leave the car like that, ring Petrol in Diesel then leave your engine switched off. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and ways to make sure you don't do it again.
Petrol in a diesel: what does it do to the engine?
Two tasks fall to diesel on its journey through a motor. Oiling comes before burning; it does both. Very fine tolerances are built into the injectors and your high-pressure pump, and just the diesel running through keeps those surfaces from grinding together.
Petrol does the first job badly and the second not at all. The rattling 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 out the lubrication your system rests on, and any pump running on such a blend is wearing itself.
Combined, those make the shape of the issue plain. Not contact but circulation is what causes the harm. A tank with petrol in it is a fuel issue. Whatever a worn pump sheds travels on, carried by your fuel, into the fuel injectors downstream, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Burnham, petrol in a diesel: four cases, from mild to major
Fuelled, and never started: no case is better. That petrol is in that tank and just the tank, and the task is a drain and a flush where your car stands. This is the one scenario that can only truly occur at a forecourt, since anywhere else the car has been driven to get there.
A moment's running, or merely your ignition on. Petrol has come out of that tank and reached the fuel filter and the lines, because the system has been primed. Drain, flush, deal with your filter: still normally simple.
Those few miles on the road meant the pump labouring on fuel thinned by petrol the whole way. The work is the tank, the lines, the fuel filter and clean fuel through the entire circuit, and how hard the vehicle was driven counts as much as how far. On the school run to St Peter's Church of England Primary School, the mileage is small. Driving as far as St Albans, under 25 miles away, makes a very different task — as does any mileage on the Huntercombe Spur, under 3 miles from Burnham, with your engine working hard all the way.
Driven on until it protested — knocking, smoke, an uneven idle, a dead throttle. What you are hearing is the engine reporting fuel that no longer runs like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Fairfield Road. What goes first is still the drain and flush, and that sorts it out, with permanent damage very uncommon if a vehicle is stopped quickly.
Burnham people and that petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It does not. Nothing comes out when you top up — that tank simply holds more of the same mixture. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." Smaller components and higher pressure are the way a modern diesel runs its fuel, and that makes the lubrication count more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. The motorist of a petrol engine fed diesel usually stops, since it will not run, and the harm stops with them. Feed petrol to a diesel and it generally starts, idles and drives away like nothing happened — all while its pump wears. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive it home." It's an old fix for a distinct problem. It does not put back what petrol has weakened, and the petrol is still inside the tank after that.
The next start sends petrol back round your pump out of your lines and your filter, where some of it ends up once the motor has been run. That is why a DIY tank drain doesn't leave you sorted — a myth. Emptying petrol into a can at the kerbside is also truly hazardous.
How does petrol in a diesel happen?
It is seldom carelessness, and no one does it on purpose. A diesel nozzle generally will not fit a petrol vehicle, yet the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and only in one direction.
When routine and the vehicle stop matching, it takes place. A vehicle that's new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. Your usual forecourt, its pumps suddenly in a different order. A hurried fill en route to the nearest station with a train to catch. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. With rain, a call coming in, or a car full of children to deal with, the hand simply does what it has always done.
Avoiding petrol in a diesel next time you fill up around Burnham
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Read the petrol pump's label; the colour is only a clue.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of vehicles state the fuel type there.
- One of each in the house? Label your key to your diesel — a bright fob, a sticker — because intending to remember isn't enough.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to block a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the pump.
- The moment you notice, stop: less petrol inside that tank means a thinner mix. What to do next does not change, though — still do not fire it up.
Burnham: already put petrol in a diesel?
In that case, there's only a short order of things. Do not turn your ignition on, and do not start it. If you're still at the forecourt — Esso or anywhere else — ask the attendants to help you roll it away from the petrol pump. What got in, about how much, and if it has run: tell us that when you ring 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate fault — Burnham has a page all for it.
Why one petrol in a diesel task around Burnham costs more than another
There is no honest single price for this, because the four scenarios above are four different tasks. Which of them you are in is mostly what shifts the cost. Beyond that it is the proportion — how much petrol got in against how much the tank holds — and then where your car is and whether our van can reach it safely.
Ahead of any quote, not after, we ask three queries: your fuel that got in, its quantity, and if it has run. That is why. The answers change a range into a straight figure.
About Burnham
Burnham is a suburban area in Buckinghamshire, situated inland at an elevation of around 55 metres. Burnham lies approximately 22.9 miles west of London and is close to nearby places such as Lent, Lent Rise, and Hitchambury. Burnham has a population of around 4977 people and is characterised by predominantly detached housing. Burnham is also near the city of St Albans, which is about 20.2 miles away.
Burnham and Buckinghamshire: where our fuel drain cover reaches
Lent, Lent Rise and Hitchambury are among the locations around Burnham that the same teams work, answering petrol in diesel call-outs across Burnham's SL postcode area. You need not move the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots where we work.
Burnham: still at the pump?
No position is better: that is where you now are. Leave the vehicle switched off, then ring.