Petrol in a Diesel Car in East Fields: How Worried Should You Be?
Not started? Then less worried than you probably are. "Have I ruined it?" is the first question anyone in East Fields asks, and the truthful answer is normally no, because petrol left in a diesel tank harms nothing until it is drawn through the fuel system — by ignition priming, by your starter, or by driving. To leave it that way, call Petrol in Diesel and leave the motor alone. What petrol actually does to a diesel, how to judge how far it has travelled, and how to stop it from happening again: that's the remainder of this page.
The motor and petrol in a diesel: what goes on
Two jobs fall to diesel on its journey round a motor. Before it combusts, it protects — and then it ignites. The high-pressure fuel pump and the injectors are made to extremely fine tolerances, and your diesel passing through them is what stops those surfaces from wearing down against each other.
The second task petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on the blend wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the clattering.
The shape of the trouble is plain when you put those together. Contact does not do the harm — circulation does. Where the petrol is only in your tank, it is a fault 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 the fuel to the injectors downstream.
How serious is petrol in a diesel? Four situations our technicians see around East Fields
The best case there is: filled up, never started. That petrol is inside the tank and just that tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only truly happen on a forecourt, because anywhere else the vehicle has been driven to get there.
Ignition on, or started for a moment. Petrol has left your tank and got to the fuel filter and the fuel lines, since your system has been primed. Still normally simple: drain, flush, and the filter seen to.
Your pump has spent a few miles on weakened fuel — that's what driving the vehicle does. How hard the vehicle was driven counts as much as how far, and the work covers that tank, your lines, the filter and fresh fuel through the entire system. On the school run to St Nicolas C.E. Junior School, the distance is short. A run as far as Winchester, under 25 miles away, is a very different task. So is any miles on the M4, under 5 miles from East Fields, where the motor has been labouring hard throughout.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven until it complained. That's the motor telling you its fuel no longer is behaving like diesel. Stop wherever you are — the verge on Stanley Road, a lay-by, a side street — and leave it there. A vehicle pulled over soon very seldom has permanent damage, as the drain and the flush, which still come first, take care of it.
What East Fields people get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing comes out when you top up — your tank just holds more of the same blend. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through finer components: that's how a modern diesel handles its fuel, so the lubrication counts more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no damage done." Diesel in a petrol motor generally means a motor that will not run: the motorist stops, and so does the damage. A diesel fed petrol generally starts, ticks over and drives away as though nothing has happened, whilst the pump grinds. Running doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. That petrol is still inside the tank after that, and whatever it has weakened is not put back.
The next start draws petrol back round your pump out of the fuel lines and your filter, where some of it ends up once your engine has run. That is why a DIY tank drain does not leave you sorted — a myth. And, a can of petrol drained at the roadside is genuinely dangerous.
How does petrol in a diesel take place?
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it easy, and the mistake runs one way.
When habit and the car stop matching, it occurs. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the driveway. Your normal forecourt, its pumps now in a different order. A rushed fill on the way to Newbury Racecourse with a train to catch. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is precisely the moment it occurs. With rain, a call coming in, or children to deal with, the hand simply does what it has always done.
East Fields people: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the petrol pump's label; the colour is only a clue.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles print the fuel there.
- Mark your key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- It sounds daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop checking the petrol pump.
- As soon as you realise, stop: less petrol inside that tank means a thinner mix. What to do next doesn't change, though — still do not fire it up.
East Fields: already put petrol in a diesel?
Short and simple, then, is the order of things. Never crank it, and don't turn the ignition on. Still at the forecourt, at Sainsbury's or anywhere else? Ask the staff to help you push the car away from the petrol pump. Next, 0333 366 0103. We will ask what went in, about how much, and if it's been run.
Corrosion and deposits form the issue with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own East Fields page.
What makes one East Fields petrol in a diesel job cost more than the next
Four separate jobs sit behind the four scenarios above — which is why there is no fair single price. The scenario itself does most of the work of moving the cost. The proportion counts next, meaning how much of your tank is petrol, followed by the position of your car and whether reaching it is safe for a technician.
Ahead of any quote, not after, we ask three questions: your fuel that got in, the quantity, and whether it's run. That's why. Those replies change a range into a straight figure.
About East Fields, briefly
East Fields is a suburban area situated on the riverside in Berkshire, with a relatively low elevation of around 80 metres. East Fields lies within the South East region of England, approximately 51.6 miles from London and 23.2 miles from the nearest city, Winchester. East Fields is close to nearby places such as Newbury, Ham Marsh, and West Fields, and is characterized by predominantly flat housing.
Fuel drain cover across Berkshire, East Fields included
Petrol in diesel jobs in East Fields — part of the RG postcode area — go to teams that also cover the locations round it, Newbury, Ham Marsh and West Fields among them. Our engineers drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In East Fields and still at the petrol pump?
Then, you couldn't be in a better place. Ring, and keep it turned off.