How Worried Should You Be? Petrol in a Diesel Car in Codsall
Far less than you likely are, provided it has not been started. Till your ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank simply sits there and does no harm. Which means the honest reply to that first Codsall question — "have I ruined it?" — usually no. To leave the vehicle that way, ring Petrol in Diesel then leave your motor switched off. The rest of this page sets out 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 again.
Inside the motor: what petrol in a diesel really does
Diesel has two jobs on its way through a motor. It burns, and before it ignites it lubricates. Extremely fine gaps are built into the fuel injectors and your high-pressure pump, and only the diesel running through keeps those surfaces from grinding together.
The second task petrol doesn't do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump running on the mixture wearing itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the clattering.
Put these together and the shape of the trouble is clear. Not contact but movement is what does the harm. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds travels on, borne by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical fault begins.
How bad is petrol in a diesel? Four scenarios our engineers see around Codsall
Filled but never started — as good as it gets. Being at a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With the petrol kept in your tank alone, it's emptied and flushed on the spot, and nothing more is needed.
Ignition on, or started for a second. Petrol has left that tank and got to the fuel filter and the fuel lines, because your system has been bled. Still normally straightforward: drain, flush, and the filter sorted.
Your pump has spent a few miles on weakened fuel — that's what driving the vehicle meant. Distance is only half of it; how hard it was driven counts just as much. Either way this work includes your tank, your lines, your filter and fresh fuel through the whole system. The school run to St Nicholas Church of England First School is one matter. Getting as far as Wolverhampton, under 5 miles away, makes a very different task — as does any distance on the M54, under a mile from Codsall, with your engine running hard all the way.
Driven on till it protested — knocking, smoke, a ragged idle, a dead throttle. What you are hearing is the motor signalling fuel that no longer runs like diesel. Pull up where you are — on the verge on Station Road, at the kerb, down a side road — and do not move it. The drain and flush still go first, and they sort it out: when a vehicle is stopped soon, permanent damage is very uncommon.
What Codsall people get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed when you top up — that tank just carries more of the same mixture. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: a modern diesel copes with a bit of petrol. Rather, the reverse. A modern diesel runs its fuel through smaller components at higher pressure, which makes the protection matter more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no damage done." Feed diesel to a petrol motor and it generally won't run, and so the motorist stops — and the damage stops with them. Whilst your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running does not mean fine.
An outdated fix for a separate problem is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It doesn't put back what petrol has thinned, and that petrol is still in that tank later on.
The next start sends petrol back round your pump out of the lines and the fuel filter, where some of that sits once your engine has been run. That's why draining the tank yourself doesn't leave you sorted — a myth. Clearing petrol into a can by the kerbside is also genuinely hazardous.
Why petrol in a diesel happens so easily
No one does it on purpose, and it's rarely carelessness. A diesel nozzle generally won't fit a petrol motor, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error easy, and just in that direction.
It occurs when habit and the car stop matching. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. Fuelling up in a rush en route to the nearest station, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: exactly when it happens. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up in Codsall: preventing petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of motors state the fuel inside your filler flap or on the cap, and so check there on your first fill in any motor you don't know.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, for a house with one of each.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems daft. It does the trick.
- Mistakes like this are straightforward to make while 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 designed to refuse a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop reading the pump.
- Spotting it halfway? Stop there and then. A thinner mixture follows from less petrol inside your tank, but your next step stays the same: don't fire it up.
Put petrol in a diesel in Codsall already?
In that case, there is only a short order of things. Don't turn your ignition on, and do not crank it. Still on the forecourt, at Esso or anywhere else? Ask the staff to help you roll the vehicle clear of the pump. Ring 0333 366 0103 next, with three answers — the fuel, the rough amount, and whether it's run.
If it was AdBlue rather than petrol, say so. That is a different problem — corrosion and deposits and not lost lubrication — and it has its own page for Codsall.
One petrol in a diesel job in Codsall costs more than another. Why?
The four situations above are four separate jobs, so no single price for this would be honest. What moves the cost is chiefly which of them you're in. Two things follow that: the petrol that went in as a share of what that tank takes, then the spot the vehicle is in and whether our van can reach it safely.
Before any quote, not after, come three questions: your fuel that went in, its volume, and whether it has run. That's why. Those answers change a range into a straight figure.
About Codsall itself
Codsall is a village in southern Staffordshire, situated on the River Penk and near the Shropshire border. Codsall sits at an elevation of around 127 metres, with nearby settlements including Oaken, Gunstone, and Lane Green. Codsall is characterized by its predominantly detached housing stock and is located close to the city of Wolverhampton, approximately 4.3 miles away. Codsall has a population of around 2634 residents, according to recent estimates.
Fuel drain cover across Staffordshire, Codsall included
Codsall sits in the WV postcode area, and our vans that answer petrol in diesel calls there work the places around it as well — Oaken, Gunstone and Lane Green among them. The car doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Codsall: still at the petrol pump?
No position is better: that's where you now are. Call, and keep it turned off.