Petrol in a Diesel Car in Newport: How Worried Should You Be?
Less than you probably are, provided it hasn't been started. Everyone around Newport starts with "have I wrecked it?", and the honest answer is generally no: petrol resting inside that tank of a diesel stays harmless until priming, cranking or driving pulls it into the system. Keep it like that: leave your motor off then phone Petrol in Diesel. The remainder of this page explains what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
Your engine and petrol in a diesel: what happens
On its way through an engine, diesel does two jobs. It combusts, and before it ignites it lubricates. Extremely fine tolerances go into the fuel injectors and the high-pressure pump, and just the diesel running through keeps those surfaces from grinding together.
The second task petrol does not do at all, and the first it does badly. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and strips out the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where the clattering comes.
Taken together, they show what shape the trouble takes. The harm is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds goes on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has been working on the petrol is where a mechanical problem starts.
Petrol in a diesel in Newport: how bad is it? Four situations
Fuelled but never started — the best it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol kept inside the tank alone, it's emptied and flushed on the spot, and nothing more is needed.
Started for a moment, or only your ignition on. Your system has been primed, and so petrol has left that tank and got to the fuel filter and the fuel lines. Still usually straightforward: drain, flush, and the fuel filter sorted.
Those few miles on the road meant the pump working on fuel weakened by petrol throughout. The work is your tank, the fuel lines, the filter and clean fuel through the whole system, and how hard your car was driven matters as much as how far. On the school run to Newport Community School Primary Academy, the distance is small. Driving as far as Exeter, under 50 miles away, makes a very different task — as does any distance on the M5, under 50 miles from Newport, with the engine labouring hard the whole time.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The engine is telling you your fuel is no longer behaving like diesel. Stop on the spot — on the verge on Cyprus Terrace, at the kerb, down a side road — and do not move it again. The fuel drain and flush-through still come first, and they take care of it: if a car is stopped soon, permanent damage is very unusual.
Stories Newport people hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you're left with a fuller tank, still the same mix. The assumption behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." More precise parts and higher pressure are how a newer diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no harm done." Any petrol engine fed diesel generally will not run, and so the driver stops and the harm stops with them. Feed petrol to a diesel and it normally fires up, ticks over and pulls away as if nothing happened — all the while its pump is wearing. A running engine doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different fault. None of what petrol weakened is put back by it — and later, that tank still contains the petrol.
The next start sends petrol back round your pump out of the lines and the filter, where some of it ends up after your engine has been run. That is why a DIY tank drain does not sort it — a myth. It is also really risky to drain petrol into a can by the kerbside.
How it happens: petrol in a diesel
Carelessness is seldom the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol car at all. So the mistake runs one way.
The moment habit stops matching the car is the moment it happens. Any motor that is new to you — a hire car, on loan as a courtesy car, or brand new. Two motors on one drive, one petrol, one diesel. A familiar forecourt with the pumps in a different order. A train to catch, and a rushed fill en route to Barnstaple. Years of petrol motors behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up in Newport: avoiding petrol in a diesel
- The label is what matters, so check the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- The first fill in an unfamiliar motor is the time to check the filler flap — on it, or on the cap, many cars state the fuel to use.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a household has one of each. So mark it.
- Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, yes, but it does the trick.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to refuse a petrol nozzle, and aftermarket devices are available for the rest. Count it as a backstop, and keep checking the petrol pump.
- Less petrol makes a weaker mixture, so stop the moment you notice — while remembering that the next step is unchanged. It's still not to crank it.
Newport: already put petrol in a diesel?
Short and simple, then, is the order of things. Do not start it, and don't switch the ignition on. Ask the attendants to help you push it away from the petrol pump if you are still at the forecourt, whether that's Esso or somewhere else. Call 0333 366 0103 next, with three answers — your fuel, the rough quantity, and if it's run.
Say so if it was AdBlue rather than petrol: it's a separate problem, with its own page for Newport, since AdBlue brings corrosion and deposits instead of lost lubrication.
Newport petrol in a diesel jobs: why one costs more than another
There's no honest single price for this, because the four scenarios above are four different jobs. Chiefly, the cost moves with which situation you're in. Two things follow that: the petrol that was put in as a proportion of what that tank holds, then the spot the car is in and whether a technician can get to it safely.
What was put in, how much, and whether it's run — three questions our technicians ask before costing, not after, for exactly that reason. The answers change a range into a straight figure.
About Newport and where it is
Newport is a suburban area in Devon, situated on the riverside with a relatively low elevation of 18 metres. Newport sits near several nearby places, including Rumsam, Whiddon, and the larger town of Barnstaple, and is located approximately 33 miles from the city of Exeter. Newport has a population of around 5697 people, predominantly living in terraced housing. Newport is also within commuting distance of larger cities, being around 172 miles from London.
Fuel drain cover across Devon, Newport included
The vans answering petrol in diesel call-outs in Newport, in the EX postcode area, equally work the places near it, Rumsam, Whiddon and Barnstaple among them. You need not bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
In Newport and still at the petrol pump?
The best spot there is, then — that's where you are. Leave it switched off, then ring.