Should You Worry? Petrol in a Diesel Car in Slinfold
Likely less than you already are — as long as no one has started the car. Until your ignition primes the pump, the starter cranks, or your vehicle is driven, petrol in a diesel tank simply waits there and does no harm. Which means the honest reply to that first Slinfold query — "have I ruined it?" — usually no. Petrol in Diesel is who to ring, with the motor kept off, so it stays that way. The rest of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
Your engine and petrol in a diesel: what happens
Passing through an engine, diesel is doing two jobs at once. Before it burns, it lubricates — and then it ignites. The high-pressure pump and the fuel injectors are designed to very fine clearances, and your diesel passing through them is what stops those surfaces from wearing against one another.
The second task petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on that mixture wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the knocking.
Put those together and the shape of the issue is clear. Not contact but movement is what causes the damage. Petrol in a tank is a fuel issue. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Slinfold, petrol in a diesel: four situations, from mild to significant
Filled up, never started. The best case there is. Being on a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With that petrol held in your tank alone, it's drained and purged on the spot, and nothing more is needed.
A brief spell of running, or merely your ignition on. With your system primed, the lines and filter now contain petrol that came from that tank. Usually nothing more than clearing, cleaning and sorting the fuel filter, so still straightforward.
Driven a few miles. Now your pump has spent those miles working on thinned fuel. Tank, lines, filter, then clean fuel run through the whole system: that is the work, and the way the car was driven counts as much as the distance. Driving the children to Slinfold CofE Primary School and Pre School is one kind of trip. A run as far as Brighton and Hove, under 25 miles away, is a very different job. So is any miles on the M23, under 10 miles from Slinfold, where the motor has been working hard throughout.
Clattering, an uneven idle, smoke, a throttle gone soft: driven until it complained. That is your engine telling you its fuel no longer is acting like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Lyons Road. Lasting damage is very unusual when a vehicle is pulled over early, and the drain and flush that still go first take care of it.
Stories Slinfold people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed when you top up — your tank just carries more of the same mixture. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. Lubrication counts more on current diesels, not less, since their fuel runs through finer parts at higher pressure.
"It starts, it drives, and so no harm done" — the myth that catches more drivers than any other. The driver of a petrol engine fed diesel normally stops, since it will not run, and the harm stops with them. While your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Running is not the same as fine.
An outdated workaround for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has weakened remains weakened, and the petrol stays inside that tank anyway.
The next start draws petrol back round your pump out of the fuel lines and the filter, where some of it ends up once your engine has run. That is why draining your tank yourself does not leave you sorted — a myth. Besides, petrol emptied into a can by the road is truly risky.
Petrol in a diesel: how does it take place?
Nobody does it on purpose, and it's rarely carelessness. A diesel nozzle mostly will not go into a petrol car, yet the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error easy, and just in that direction.
The moment routine stops matching the vehicle is the moment it happens. Courtesy car, hire car, or a car that's brand new. A household with one petrol and one diesel on the driveway. Your usual forecourt, its pumps suddenly in a different order. Filling up in a hurry on the way to Christs Hospital, with a train to catch. A new-to-you diesel Peugeot 308, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Slinfold people: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the petrol pump's label; the colour is only a hint.
- Check your filler flap. Many motors state the fuel inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- One of each in the house? Label the key to the diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car gets its first tank. It sounds daft. It works.
- Mistakes like this are straightforward to make whilst your mind is on something else, and so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for motors without one. They are a backstop, not a reason to stop checking the pump.
- The moment you realise, stop: less petrol inside that tank makes a weaker blend. What to do next doesn't change, though — still do not start the vehicle.
Slinfold: already put petrol in a diesel?
In that case, there's only a short order of things. Leave it unstarted, with your ignition off as well. Still at the forecourt, at Tesco or anywhere else? Ask the attendants to help you push the car clear of the pump. Next, 0333 366 0103. We will ask what went in, roughly how much, and if it's been run.
Say so if it was AdBlue instead of petrol: it is a different fault, with its own page for Slinfold, since AdBlue brings corrosion and deposits rather than lost lubrication.
One petrol in a diesel task in Slinfold costs more than another. Why?
A fair single price does not exist here: four situations, four separate jobs. Chiefly, your cost shifts with which situation you are in. Two things follow that: the petrol that went in as a share of what your tank holds, then the place the vehicle is in and whether a technician can get to it safely.
That is why we ask three queries before quoting instead of after: what went in, how much, and whether it has run. Their answers are what change a range into one firm number.
About Slinfold itself
Slinfold is a village situated in the riverside setting of the West Sussex countryside, with an elevation of around 35 metres. Slinfold lies near the villages of Rapkyns, Itchingfield, and Strood Green, and is approximately 20.5 miles from Brighton and Hove. Slinfold has a population of around 1163 people, predominantly living in detached housing. Slinfold is also within commuting distance of London, being around 32.5 miles from the capital.
Across West Sussex and in Slinfold: fuel drain cover
Petrol in diesel call-outs around Slinfold — part of the RH postcode area — go to vans that likewise cover the places about it, Rapkyns, Itchingfield and Strood Green included. The car doesn't need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Slinfold: still at the petrol pump?
Then, you couldn't be in a better position. Switched off it remains; then ring.