Greenfaulds: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, provided it has not been started. Everyone around Greenfaulds starts with "have I ruined it?", and the honest answer is normally no: petrol left in the tank of a diesel stays harmless till priming, cranking or driving draws it into your fuel system. Petrol in Diesel is who to phone, with your motor kept off, so it stays that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and ways to make sure you never repeat it.
What petrol in a diesel does to the motor
Two jobs fall to diesel on its route round a motor. It combusts, and before it combusts it protects. What keeps the surfaces inside the high-pressure fuel pump and the injectors from wearing against one another is the diesel flowing through them — they're designed to extremely fine clearances.
The second task petrol does not do at all, and the first it does badly. The knocking comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection the system rests on, and any pump running on such a blend is wearing itself.
The shape of the problem is plain once you put those together. It is circulation that causes the damage, not contact. All a tank with petrol in it amounts to is a fuel fault. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Petrol in a diesel in Greenfaulds: how serious is it? Four situations
The best case there can be: filled up, not once started. That petrol is in your tank and only that tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only really take place at a forecourt, because anywhere else your car has been driven to get there.
Ignition on, or started for a moment. With the system primed, the fuel lines and filter already hold petrol that came from your tank. Still generally simple: drain, flush, and your filter seen to.
Those few miles driven meant your pump running on fuel weakened by petrol throughout. How hard your car was driven matters as much as how far, and this work covers the tank, the fuel lines, your filter and clean fuel through the entire system. The school run to the local primary school is one matter. Getting as far as Glasgow, under 15 miles away, makes a very different job — as does any mileage on the M80, under a mile from Greenfaulds, with your engine working hard the whole time.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. What you are hearing is your engine reporting fuel that no longer behaves like diesel. Whether it's the verge on Lammermoor Drive, a lay-by or a side street, stop there then leave it. What comes first is still the fuel drain and flush-through, and that deals with it, with lasting damage very uncommon if a car is pulled over early.
Petrol in a diesel myths Greenfaulds 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 when you top up — the tank just carries more of the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: a newer diesel copes with a bit of petrol. If anything, the reverse. A newer diesel sends its fuel through finer parts at higher pressure, which makes the lubrication matter more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. A petrol engine fed diesel generally will not run, and so the motorist stops and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, while the pump grinds. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. What petrol has diluted stays thinned, and the petrol remains inside your tank anyway.
Myth: "Drain the tank yourself and you're sorted." After your engine has run, some of the petrol is no longer in your tank: it's in the filter and the fuel lines, and it goes straight back through the pump at your next start. Draining petrol into a can by the kerbside is also truly dangerous.
How it happens: petrol in a diesel
No one does it on purpose, and it is seldom carelessness. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol vehicle at all. So the mistake runs one way.
When routine and the vehicle stop matching, it happens. Courtesy car, hire car, or a vehicle that's new. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to the nearest station. Exactly the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. Add a back seat full of children, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up in Greenfaulds
- The label is what matters, and so check the pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- Check the filler flap. Plenty of 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 home? Mark your key to the diesel — a bright fob, a sticker — because intending to remember is not enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It sounds silly and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away and keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to block a petrol nozzle, and add-on devices exist for the rest. Treat it as a backstop, then keep checking the petrol pump.
- Noticing it halfway? Stop at once. A weaker mixture follows from less petrol in your tank, but your next step remains the same: don't fire it up.
Greenfaulds: already put petrol in a diesel?
Then, there's only a short order of things. Do not turn your ignition on, and do not crank it. Yet on the forecourt, at Tesco or anywhere else? Ask the staff to help you push the car away from the pump. Next, 0333 366 0103. We will ask what got in, about how much, and if it's been run.
Corrosion and deposits form the problem with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Greenfaulds page.
What makes one Greenfaulds petrol in a diesel task cost more than the next
An honest single quote does not exist here: four situations, four separate tasks. What shifts the cost is mostly which of them you are in. Where your car is counts too, and whether a technician can safely reach it, after the ratio of petrol to what the tank holds.
That is why our technicians ask three queries before quoting instead of after: what went in, how much, and whether it has run. A range turns into a straight figure once the replies are in.
About Greenfaulds itself
Greenfaulds is a suburban area situated on the riverside in North Lanarkshire, with a mix of terraced housing and local amenities. Greenfaulds sits at an elevation of 115 metres, close to the nearby towns of Cumbernauld and Blairlinn. Greenfaulds is located approximately 10.5 miles from Glasgow, making it a commuter-friendly location. Greenfaulds has a population of around 4409 residents, with many families and individuals calling the area home.
Across North Lanarkshire and in Greenfaulds: fuel drain cover
Greenfaulds waits in the G postcode area, and the vans that answer petrol in diesel call-outs there work the spots near it as well — Cumbernauld, Blairlinn and Seafar among them. Our engineers drain where the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the petrol pump in Greenfaulds?
The best position there is, then — that is where you are. Turned off it stays; then ring.