Should You Worry? Petrol in a Diesel Car in Lavendon
Far less than you probably are, provided it has not been started. Until your ignition primes your pump, your starter cranks, or the vehicle is driven, petrol in a diesel tank simply sits there and does no harm. Which means the honest reply to the first Lavendon query — "have I ruined it?" — usually no. To leave the vehicle that way, ring Petrol in Diesel then leave the engine alone. What petrol actually does to a diesel, how to judge how far it's travelled, and how to stop it from happening again: that is the remainder of this page.
Your engine and petrol in a diesel: what happens
On its way through an engine, diesel has two jobs. Oiling comes before burning; it does both. Made to extremely fine gaps, the injectors and the pump depend on your diesel moving through them to keep their surfaces from wearing against one another.
The second task petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away 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 why you get the rattling.
Put these together and the shape of the issue is plain. It's circulation that causes the damage, not contact. Where the petrol is only inside that tank, it is a fault of fuel, nothing more. The start of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors beyond it.
Lavendon, petrol in a diesel: four cases, from mild to significant
Filled up, and never started: nothing beats it. The petrol is inside that tank and just your tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only truly occur on a forecourt, since anywhere else your car has been driven to get there.
Started for a moment, or only your ignition on. Once primed, the system has drawn petrol out of your tank as far as the filter and your lines. Drain, flush, deal with the fuel filter: still usually straightforward.
Driven a few miles. Now your pump has spent those miles working on diluted fuel. The work is your tank, the lines, the fuel filter and fresh fuel through the entire circuit, and how hard your car was driven counts as much as how far. On the school run to Lavendon School, the miles is small. A run as far as Milton Keynes, under 10 miles away, is a very different job. So is any miles on the M1, under 10 miles from Lavendon, where the engine has been labouring hard the whole time.
Driven on till it complained — clattering, smoke, an uneven idle, a dead throttle. What you are hearing is your motor signalling fuel that no longer runs like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Olney Road. A vehicle stopped early very seldom has permanent damage, because the fuel drain and the flush, which still come first, deal with it.
Petrol in a diesel myths Lavendon drivers hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A bigger tank of the same mix is all it gives, since topping up removes nothing. The idea behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. Lubrication counts more on current diesels, not less, because their fuel runs through smaller components at higher pressure.
This is the one that catches motorists. Myth: "If it starts and drives, there's no harm done." The driver of a petrol motor fed diesel normally stops, since it will not run, and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump wears. Running is not the same as fine.
Not so: a two-stroke additive lets you to drive home. It was an old fix, meant for another fault. It does not put back what petrol has thinned, and that petrol is still inside that tank later.
If the engine has run, part of that petrol sits in the fuel filter and your lines, not the tank — and your next start sends it straight back through your pump. So the myth "drain your tank yourself and you are sorted" doesn't hold. Besides, petrol emptied into a can by the road is truly hazardous.
How it happens: petrol in a diesel
It's seldom carelessness, and no one does it on purpose. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it straightforward.
The moment habit stops matching your car is the moment it happens. A new motor, a hire car or a courtesy car. Two cars on one drive, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. Racing for a train at Bedford and fuelling up en route. A new-to-you diesel Skoda Octavia, its first fuelling, and a driver used to petrol: precisely when it takes place. The hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Lavendon motorists: how to prevent petrol in a diesel next time
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what matters.
- The first fill in a strange car is the time to check the filler flap — on it, or on the cap, plenty of vehicles state the fuel to use.
- One of each in the household? Mark your key to your diesel — a bright fob, a sticker — because intending to remember is not enough.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and add-on devices are available for the remainder. Count it as a safety net, then keep reading the petrol pump.
- As soon as you notice, stop: less petrol inside that tank makes a thinner mix. What to do next doesn't change, though — still do not fire it up.
Petrol already in a diesel around Lavendon? Start here
The order of things is brief, then. Don't fire it up, and don't turn the ignition on. If you're still at the forecourt — Applegreen or anywhere else — ask the attendants to help you push the vehicle clear of the pump. What was put in, about how much, and whether it's run: tell us those when you phone 0333 366 0103.
Say so if it was AdBlue rather than petrol: it's a separate problem, with its own page for Lavendon, since AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Lavendon petrol in a diesel job cost more than the next
There's no fair single price for this, since the four situations above are four separate tasks. What moves your cost is chiefly which of them you're in. The proportion counts next, meaning how much of that tank is petrol, and then the location of the car and whether reaching it is safe for a van.
Before any quote, not after, we ask three questions: your fuel that was put in, the amount, and if it has run. That is why. Those replies are what change a range into one firm number.
About Lavendon itself
Lavendon is a village in north Buckinghamshire, situated in a rural area near the border with Bedfordshire. Lavendon sits at an elevation of around 62 metres, with the village centre surrounded by open countryside and nearby settlements like Cold Brayfield and Newton Blossomville. Lavendon is characterized by its predominantly detached housing stock, reflecting its role as a residential community within commuting distance of Milton Keynes. Lavendon remains a small, quiet village with a population of around 1060 residents.
Fuel drain cover around Lavendon and across Buckinghamshire
Our teams answering petrol in diesel call-outs around Lavendon, in the MK postcode area, also work the spots near it, Cold Brayfield, Warrington and Newton Blossomville among them. We drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Lavendon and still at the pump?
Then you're in the best position there is. Keep it off. Ring.