Boldon Colliery: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you likely feel. "Have I ruined it?" is the first thing anyone in Boldon Colliery asks, and the truthful answer is generally no, since petrol left in a diesel tank harms nothing until it is drawn through your fuel system — by ignition priming, by the starter, or by driving. To leave the vehicle like that, phone Petrol in Diesel then leave your engine alone. Further down, this page sets out what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the motor?
Passing through a motor, diesel is doing two things at once. Oiling comes before burning; it does both. Made to very fine gaps, the injectors and the pump depend on the diesel moving through them to stop their surfaces wearing against one another.
Petrol does the first task badly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is runnier than diesel and strips out the lubrication your fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any rattling comes.
Combined, those make the shape of the issue plain. It is movement that causes the damage, not contact. A tank with petrol in it is a fuel issue. After the pump has been labouring on that petrol, a mechanical fault has started: whatever is shed by a pump that is wearing down is carried downstream to the fuel injectors with the fuel.
How serious is petrol in a diesel? Four situations we see in Boldon Colliery
The best case there can be: filled up, not once started. Just that tank has petrol in it, and so the job is emptying your tank and flushing the system where the car stands. This scenario can only really take place on a forecourt: anywhere else, the car got there by being driven.
Started for a second, or just your ignition on. Once primed, your system has drawn petrol out of that tank up to the fuel filter and the lines. Usually nothing more than emptying, rinsing and sorting your filter, so still simple.
The pump has spent a few miles on thinned fuel — that's what driving the vehicle meant. Miles is only half of it; how hard it was driven matters just as much. Either way this work runs to that tank, your lines, the filter and fresh fuel through the entire system. Driving the children to Hedworth Lane Primary School is one kind of trip. Any mileage on the A194(M), under 3 miles from Boldon Colliery, means the engine has worked hard throughout, and a run to Sunderland, under 5 miles away, is a very different job as well.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. That is your motor telling you its fuel no longer is acting like diesel. Stop where you are — on the verge on Lawson Court, at the kerb, down a side road — and don't move it. The drain and flush-through still come first, and they deal with it: when a car is pulled over early, permanent damage is very unusual.
Petrol in a diesel stories Boldon Colliery motorists hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you're left with a fuller tank, still the same mix. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and closer to the reverse. Protection counts more on modern diesels, not less, because their fuel runs through more precise components at higher pressure.
"It starts, it drives, so there is no harm" — the myth that trips up most motorists than any other. The driver of a petrol motor fed diesel normally stops, since it will not run, and the damage stops there. Feed petrol to a diesel and it usually fires up, ticks over and pulls away as if nothing happened — all while its pump wears. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated workaround for a separate issue. That petrol is still inside that tank afterwards, and what it has weakened isn't put back.
If the engine has been run, part of that petrol sits in the fuel filter and the lines, not the tank — and your next start sends it right back through your pump. So the myth "drain the tank yourself and you're sorted" doesn't stand up. Clearing petrol into a can by the roadside is also really hazardous.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle generally won't fit a petrol vehicle, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and only in that direction.
Habit and the car falling out of step is when it occurs. A motor that's new to you — hired, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps now in a different order. Rushing for a train at Brockley Whins and filling up en route. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up in Boldon Colliery: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a strange vehicle is the time to check your filler flap — on it, or on the cap, plenty of cars state which fuel they take.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds daft. It does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Add-on devices are available for motors without one, and some diesels are built with a filler that will not accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol in the tank means a thinner mixture. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel in Boldon Colliery already?
Then the order of things is brief. Starting it is out, and so is turning on the ignition. If you're still at the forecourt — Asda or anywhere else — ask the attendants to help you push the vehicle clear of the pump. Phone 0333 366 0103 next, with three answers — the fuel, the approximate volume, and if it has run.
If it was AdBlue rather than petrol, say so. That is a separate fault — corrosion and deposits rather than lost protection — and it has its own page for Boldon Colliery.
What makes one Boldon Colliery petrol in a diesel job cost more than the next
Four separate tasks lie behind the four scenarios above — which is why there is no fair single quote. The situation itself does most of the work of moving your cost. The ratio matters next, meaning how much of that tank is petrol, and then the location of the vehicle and whether reaching it is safe for a van.
Ahead of any quote, not after, we ask three queries: the fuel that went in, the amount, and whether it has run. That's why. Those replies are what turn a range into one firm number.
About Boldon Colliery and where it is
Boldon Colliery is a locality situated on the banks of the River Wear in Tyne and Wear, with nearby settlements including West Boldon and Hedworth. Boldon Colliery has a mix of housing types, but predominantly features terraced homes. Boldon Colliery is located close to the city of Sunderland, which is approximately 4 miles away. Boldon Colliery sits at a relatively low elevation of around 30 metres above sea level.
Fuel drain cover across Tyne and Wear, Boldon Colliery included
The teams answering petrol in diesel call-outs in Boldon Colliery, in the NE postcode area, equally work the places near it, West Boldon, Hedworth and Biddick Hall among them. Our technicians drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the pump in Boldon Colliery?
In that case, you could not be in a better spot. Switched off it remains; then phone.