Should You Worry? Petrol in a Diesel Car in Danestone
Probably less than you already are — as long as no one has started the vehicle. Till the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just sits there and does no harm. Which makes the truthful reply to the first Danestone question — "have I wrecked it?" — usually no. Keep it like that: leave your engine off and ring Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it has travelled, and how to stop it from happening a second time: that's the rest of this page.
What petrol in a diesel does to the motor
Diesel has two jobs on its way through a motor. It lubricates first, and after that does it burn. What stops the surfaces inside your high-pressure pump and your injectors from grinding against each other is the diesel flowing through them — they're made to very fine tolerances.
Petrol does the first task poorly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump on the mixture to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the clattering.
The shape of the problem is plain once you put those together. Contact doesn't do the damage — movement does. Any tank with petrol in it is a fuel issue. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to your injectors further on.
How bad is petrol in a diesel? Four situations our technicians see in Danestone
Fuelled up, never started. The best case there can be. The petrol is inside that tank and only the tank, and the job is a drain and a flush where the car sits. This is the one situation that can only truly occur at a forecourt, because anywhere else the car has been driven to get there.
Your ignition switched on, or a short start. The system has been bled, and so petrol has left your tank and got to your filter and the lines. Usually little more than draining, rinsing and seeing to the filter, and so still straightforward.
Those few miles on the road were the pump running on fuel thinned by petrol throughout. How hard the vehicle was driven counts as much as how far, and this work covers that tank, your lines, the fuel filter and fresh fuel through the whole circuit. A school run to the local primary school is one matter. Driving as far as Aberdeen, under 3 miles away, makes a very different task — as does any miles on the M90, over 50 miles from Danestone, with the engine labouring hard the whole time.
Driven on till it protested — knocking, smoke, a lumpy idle, a dead throttle. The motor is telling you the fuel is no longer acting like diesel. Pull up wherever you are — the verge on Laurel Drive, a lay-by, a side street — and leave the vehicle where it is. Permanent damage is very uncommon if a car is pulled over early, and the drain and flush that still go first sort it out.
Petrol in a diesel myths Danestone people hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a bigger tank, still the same mix. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: a current diesel copes with a bit of petrol. Rather, the reverse. At higher pressure, through smaller components: that is how a newer diesel moves its fuel, so the protection matters more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor usually means a motor that won't run: the motorist stops, and so does the harm. While your pump wears, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Running doesn't mean fine.
An outdated workaround for a different problem lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol diluted is put back by it — and afterwards, the tank still holds the petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol sits in your filter and lines, waiting to go straight back through the pump on the next start. And, a can of petrol filled by the roadside is genuinely dangerous.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
The moment habit stops matching the car is the moment it takes place. Any car that is new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the driveway. Your normal forecourt, its pumps suddenly in a different order. Fuelling up in a rush en route to Dyce, with a train to catch. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Throw in rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up in Danestone
- Green for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- Check the filler flap. Many cars state the fuel inside the flap or on the cap. Look at it on your first fill in a vehicle you do not know.
- One of each in the house? Label the key to your diesel — a coloured fob, a sticker — because meaning to remember is not enough.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car gets its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to refuse a petrol nozzle, and aftermarket devices exist for the remainder. Count it as a safety net, and keep checking the petrol pump.
- Stop the moment you realise. Less petrol in the tank makes a thinner mixture. It does not change what to do next, which is still not to start it.
Danestone: already put petrol in a diesel?
In that case, there's only a short order of things. Don't switch your ignition on, and do not start it. Ask the attendants to help you push it away from the pump if you're still on the forecourt, whether that is Tesco Extra or somewhere else. Next, 0333 366 0103. We will ask what got in, roughly how much, and if it's been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate fault — Danestone has a page all for it.
One petrol in a diesel task around Danestone costs more than another. Why?
The four situations above are four separate jobs, so no single quote for this would be fair. The situation itself does most of the work of moving the cost. Next it is the proportion — how much petrol got in against how much your tank holds — and then where your car is and whether a technician can reach it safely.
What was put in, how much, and if it has run — three questions our engineers ask before costing, not after, for exactly that reason. Those answers turn a range into a straight figure.
About Danestone and where it is
Danestone is a suburban area located on the coast of Aberdeen City, sitting at an elevation of 36 metres and approximately 2.8 miles from Aberdeen city centre. Danestone is characterized by its semi-detached housing and is situated near other local areas such as Woodside, Middlefield, and Cummings Park. Danestone has a population of around 2899 residents and is part of the larger Aberdeen urban area. Danestone is also relatively distant from major English cities, with London being around 400 miles away.
Fuel drain cover across Aberdeen City, Danestone included
Woodside, Middlefield and Cummings Park are among the spots near Danestone that the same vans work, answering petrol in diesel calls across Danestone's AB postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians drain, and your car does not need to move to us.
At the petrol pump around Danestone, still?
Then, you couldn't be in a better spot. Ring, and leave it switched off.