How Worried Should You Be? Petrol in a Diesel Car in Holcombe
If it hasn't been started, you can worry less than you probably are. "Have I ruined it?" is the first thing everyone around Holcombe asks, and the honest answer is normally no, since petrol resting in a diesel tank hurts nothing until it's dragged through your fuel system — by ignition priming, by the starter, or by driving. To keep the car like that, ring Petrol in Diesel and leave the engine alone. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening again: that is the remainder of this page.
Inside the motor: what petrol in a diesel really does
On its way through a motor, diesel has two jobs. It ignites, and before it combusts it lubricates. Built to extremely fine tolerances, the injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Petrol handles the first job poorly and the second not at all. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump on the mixture to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the knocking.
Together, those leave the shape of the issue plain. The damage is done by movement, not by contact. Where the petrol is only inside your tank, it is a fault of fuel, nothing more. 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 the fuel to the fuel injectors downstream.
How serious is petrol in a diesel? Four situations we see in Holcombe
Fuelled but never started — the best it gets. Only that tank has petrol in it, and so the task is emptying that tank and rinsing your system where the car stands. This situation can only really occur at a forecourt: anywhere else, your car got there by being driven.
The ignition switched on, or a short start. Petrol has come out of the tank and reached the fuel filter and the fuel lines, because your system has been primed. Still generally simple: drain, flush, and the fuel filter seen to.
Driven a few miles. Now the pump has spent those miles running on thinned fuel. The work is the tank, the lines, your filter and fresh fuel through the entire circuit, and how hard the car was driven matters as much as how far. The school run to Emmanuel Holcombe Church of England Primary School is one matter. A run as far as Salford, under 15 miles away, is a very different task. So is any mileage on the M66, under 3 miles from Holcombe, where the engine has been working hard the whole time.
Clattering, an uneven idle, smoke, a throttle gone soft: driven till it complained. The fuel is not behaving like diesel any more, and the motor is saying so. Whether it's the verge on Lumb Carr Road, a lay-by or a side road, stop there and leave it. The drain and flush still go first, and they deal with it: if a car is stopped early, long-term damage is very unusual.
Myths Holcombe drivers hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, whatever that advice presumes.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through finer parts: that's how a current diesel moves its fuel, and so the lubrication matters more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more drivers than any other. Diesel in a petrol motor normally leaves a motor that will not run: the driver stops, and so does the harm. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, whilst your pump wears. Fine and running aren't the same at all.
Myth: a two-stroke additive makes it safe to drive home. It was an old workaround, supposed for another problem. None of what petrol thinned is put back by it — and afterwards, your tank still contains that petrol.
The next start sends petrol back round the pump from the lines and the filter, where some of it ends up after the engine has been run. That's why a DIY tank drain does not sort it — a myth. Besides, petrol cleared into a can by the road is genuinely risky.
How does petrol in a diesel happen?
Nobody does it on purpose, and it's rarely carelessness. A diesel nozzle generally won't fit a petrol motor, but the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and just in that direction.
When routine and the car stop matching, it takes place. Any motor that's new to you — hired, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps laid out differently. A hurried fill en route to Entwistle with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: precisely when it takes place. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done.
Preventing petrol in a diesel next time you fill up in Holcombe
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what counts.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of motors print the fuel type there.
- One of each in the home? Mark the 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 lift the nozzle off the petrol pump. It seems daft and 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 take a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol in your tank means a weaker mix. It doesn't change what to do next, which is still not to start the vehicle.
Put petrol in a diesel in Holcombe already?
Then the order of things is short. Starting it is out, and so is turning on the ignition. If you're still on the forecourt — EG On the Move or anywhere else — ask the attendants to help you roll the car clear of the petrol pump. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate issue — Holcombe has a page all for it.
Holcombe petrol in a diesel tasks: why one costs more than another
There is no honest single price for this, because the four situations above are four different tasks. What moves your cost is chiefly which of them you're in. After that it's the share — how much petrol was put in against how much that tank holds — and then where your car is and whether our van can get to it safely.
That is why our technicians ask three queries before quoting instead of after: what got in, how much, and if it has run. With those answers, there is a straight figure rather than a range.
About Holcombe
Holcombe is a small village in Greater Manchester, situated inland at an elevation of 246 metres. Holcombe lies near several nearby places, including Tanners, Tagg Wood, and Carr, and is approximately 11.5 miles from the city of Salford. Holcombe has a population of around 510 people and is characterised by predominantly terraced housing. Holcombe is also relatively distant from London, at a distance of 174.3 miles.
Fuel drain cover across Greater Manchester, Holcombe included
Our teams answering petrol in diesel jobs around Holcombe, in the BL postcode area, equally work the locations around it, Tanners, Tagg Wood and Carr among them. The car doesn't need to move to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Holcombe and still at the petrol pump?
No position is better: that is where you now are. Leave the vehicle turned off, then ring.