How Worried Should You Be? Petrol in a Diesel Car in Newburn
Likely less than you are now — as long as nobody has started the car. Until the ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank just rests there and does nothing. Which makes the truthful reply to the first Newburn query — "have I wrecked it?" — normally no. Leave your motor off then ring Petrol in Diesel — that is how you keep it like that. Further down, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to your engine?
On its way through an engine, diesel does two jobs. It ignites, and before it burns it protects. What stops the surfaces inside your high-pressure pump and the injectors from grinding against one another is the diesel passing through them — they're designed to very fine tolerances.
Petrol does the first job poorly and the second not at all. A pump working on a petrol mixture is wearing itself out, because petrol is thinner than diesel and strips out the lubrication your fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that's where the knocking starts.
Combined, those make the shape of the trouble plain. It is circulation that does the harm, not contact. All a tank with petrol in it amounts to is a fuel problem. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Four scenarios our technicians see around Newburn: how bad is petrol in a diesel?
Filled but never started — the best it gets. On a forecourt, and truly only there, that petrol is still limited to the tank — since anywhere else your car was driven to reach it. The job is emptying and flushing on the spot.
Started for a second, or just the ignition on. Once primed, your system has pulled petrol from the tank as far as your filter and your lines. Still generally simple: drain, flush, and your filter sorted.
Driven a couple of miles. Now the pump has spent those miles running on diluted fuel. Tank, lines, filter, then fresh fuel run through the whole circuit: that is this work, and the way the vehicle was driven counts as much as the mileage. On the school run to Newburn Manor Primary School, the miles is short. Any miles on the Central Motorway East, under 10 miles from Newburn, means your engine working hard throughout, and a run to Newcastle upon Tyne, under 10 miles away, is a very different task too.
Driven on till it complained — rattling, smoke, a ragged idle, a dead throttle. The motor is telling you the fuel is no longer acting like diesel. Stop on the spot — on the verge on High Street, at the kerb, down a side road — and do not move it. The fuel drain and flush still go first, and they take care of it: if a vehicle is pulled over quickly, lasting damage is very unusual.
Petrol in a diesel myths Newburn people hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. That guidance presumes a diesel fuel system tolerates petrol by percentage. It does not.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. At higher pressure, through smaller parts: that is how a current diesel handles its fuel, so the lubrication counts for more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the harm. Feed petrol to a diesel and it usually fires up, idles and drives away like nothing has happened — all while its pump wears. Fine and running are not the same at all.
An old fix for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has weakened stays weakened, and that petrol remains inside the tank regardless.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in the filter and lines, waiting to go right back through your pump on the next start. On top of that, petrol cleared into a can by the road is genuinely hazardous.
How does petrol in a diesel take place?
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol car. That's how the forecourt makes it straightforward.
It occurs when habit and the car stop matching. Hire cars, courtesy cars, and cars that are new to you. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a familiar forecourt. Fuelling up in a rush on the way to Blaydon, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver used to petrol: exactly when it happens. Add a back seat full of children, a phone call or rain, and habit takes over.
Newburn people: how to prevent petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what matters.
- Check the filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you do not know.
- Label 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.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It seems daft. It works.
- Whilst you are thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to refuse a petrol nozzle, and add-on devices are available for motors without one. They are a safety net, not a reason to stop reading the pump.
- Stop the moment you realise. Less petrol in that tank makes a thinner blend. It does not change what to do next, which is still not to crank it.
Newburn: already put petrol in a diesel?
Then the order of things is short. Don't turn your ignition on, and don't crank it. If you're still on the forecourt — Gulf or anywhere else — ask the attendants to help you roll the car clear of the petrol pump. Then call 0333 366 0103 and tell us what was put in, roughly how much, and whether it has run.
Say so if it was AdBlue rather than petrol: it is a separate issue, with its own page for Newburn, since AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel task around Newburn costs more than another
An honest single price doesn't exist here: four scenarios, four separate tasks. Mostly, the cost shifts with which situation you're in. The proportion counts next, meaning how much of the tank is petrol, and then the position of the car and whether reaching it is safe for our van.
That's why our technicians ask three questions before pricing instead of after: what was put in, how much, and whether it has run. The replies change a range into a straight figure.
About Newburn and its setting
Newburn is a village situated on the north bank of the River Tyne in Tyne and Wear, approximately 5 miles from Newcastle upon Tyne. Newburn sits at a low elevation of around 20 metres above sea level, with the river flowing through the village. Newburn is characterised by its terraced housing and is located near other settlements such as Walbottle and Stella. Newburn has a population of around 1475 people and is part of the wider Newcastle upon Tyne urban area.
Newburn and Tyne and Wear: where our fuel drain cover reaches
Newburn sits in the NE postcode area, and our vans that answer petrol in diesel call-outs there work the places around it as well — Walbottle, Stella and Hedgefield among them. The car doesn't need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the petrol pump in Newburn, still?
Then, you could not be in a better place. Turned off it stays; then call.