How Worried Should You Be? Petrol in a Diesel Car in Rockgreen
Likely less than you are now — provided nobody has started the car. Petrol sitting in a diesel tank does nothing to the motor until something pulls it through your fuel system — your ignition priming the pump, the starter, or the drive itself. So the fair answer to the first question everyone around Rockgreen asks, "have I wrecked it?", is normally no. Keep it like that: leave your motor off then call Petrol in Diesel. The remainder of this page covers what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
Petrol in a diesel: what does it do to the motor?
Diesel does two jobs on its way through a motor. It protects to begin with, and after that does it burn. Made to very fine clearances, your injectors and your pump depend on the diesel moving through them to stop their surfaces wearing against one another.
Of these two jobs, petrol manages the first badly and the second never. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the blend to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
Put those together and the shape of the trouble is plain. Contact doesn't do the damage — movement does. Any tank with petrol in it is a fuel problem. After the pump has been labouring on that petrol, a mechanical problem has begun: anything shed by a pump that's wearing is carried downstream to the fuel injectors with the fuel.
Rockgreen, petrol in a diesel: four situations, from mild to serious
The best case there can be: filled up, not once started. On a forecourt, and genuinely only there, that petrol is still limited to your tank — because everywhere else your car was driven to get to it. The task is draining and purging on the spot.
A moment's running, or just your ignition on. With your system primed, the lines and filter already contain petrol that came from your tank. That is generally still a straightforward task — a drain, a flush, and the filter seen to.
Those few miles driven meant your pump working on fuel weakened by petrol the whole way. How hard the car was driven matters as much as how far, and the work takes in that tank, the fuel lines, the fuel filter and clean fuel through the entire system. On the school run to Ludlow Primary School, the mileage is small. Any mileage on the M54, under 25 miles from Rockgreen, means your engine has worked hard throughout, and a run to Hereford, under 25 miles away, is a very different job as well.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone lumpy. What you are hearing is your motor signalling fuel that no longer runs like diesel. Whether it's the verge on Rocks Green Crescent, a lay-by or a side street, stop where you are and leave it. The drain and flush still come first, and they deal with it: if a car is pulled over soon, lasting damage is very rare.
What Rockgreen people get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you are left with a bigger tank, still the same mix. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice presumes.
If anything, the opposite is true. Myth: "A modern diesel can cope with a bit of petrol." Protection counts more on newer diesels, not less, because their fuel passes through smaller components at higher pressure.
This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." Diesel in a petrol motor usually leaves a motor that won't run: the motorist stops, and so does the harm. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, while the pump grinds. Fine and running aren't the same at all.
An old workaround for a distinct issue lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol diluted is put back by it — and afterwards, that tank still holds that petrol.
The next start draws petrol back round your pump out of the fuel lines and your filter, where some of that ends up after the engine has been run. That is why a DIY tank drain does not sort it — a myth. Clearing petrol into a can at the roadside is also truly dangerous.
Petrol in a diesel: how does it occur?
On purpose? Never. Through carelessness? Seldom, if ever. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol vehicle. That's how the forecourt makes it simple.
The moment habit stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a vehicle that's new. Two motors on one driveway, one petrol, one diesel. Your ordinary forecourt, its pumps now in a different order. A train to catch, and a rushed fill en route to Ludlow. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of children.
How to avoid petrol in a diesel on your next fill-up around Rockgreen
- The label is what counts, so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- Plenty of cars state the fuel type inside the filler flap or on the cap, so check it on your first fill in a vehicle you don't know.
- Mark your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- 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 sounds daft and 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 have a filler designed to reject a petrol nozzle, and add-on devices are available for vehicles without one. They are a backstop, not a reason to stop reading the petrol pump.
- Less petrol makes a weaker blend, and so stop the moment you realise — while remembering that the next stage is unchanged. It's still not to fire it up.
Already put petrol in a diesel in Rockgreen?
Then the order of things is brief. Do not switch the ignition on, and don't fire it up. Ask the attendants to help you roll it away from the pump if you're still at the forecourt, whether that is Applegreen or somewhere else. Phone 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and whether it's run.
If it was AdBlue and not petrol, say so. That is a separate fault — corrosion and deposits instead of lost lubrication — and it has its own page for Rockgreen.
Rockgreen petrol in a diesel tasks: why one costs more than another
There is no honest single quote for this, because the four situations above are four separate tasks. Mostly, your cost shifts with which one you are in. Two things follow that: the petrol that went in as a proportion of what that tank takes, then the place your car is in and whether a technician can reach it safely.
What got in, how much, and whether it has run — three questions our technicians ask before costing, not after, for precisely that reason. Their replies are what turn a range into one firm number.
About Rockgreen
Rockgreen is a village situated on the riverside in Shropshire, with a population of around 890 people. Rockgreen has a mix of housing types, but semi-detached homes are the most common. Rockgreen is located near the towns of Ludlow and Hereford, and is close to other small villages such as Sheet and Lower Ledwyche. Rockgreen sits at an elevation of 115 metres above sea level, in a scenic area of the West Midlands region.
Across Shropshire and around Rockgreen: fuel drain cover
Ludlow, Sheet and Lower Ledwyche are among the spots around Rockgreen that the same teams work, answering petrol in diesel calls across Rockgreen's SY postcode area. The vehicle doesn't need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Rockgreen: still at the pump?
Then you are in the best place there is. Keep the car turned off, and ring.