Gaer: Petrol in a Diesel Car? How Worried to Be
If it hasn't been started, worry less than you likely are. "Have I ruined it?" is the first thing anyone around Gaer asks, and the honest answer is normally no, because petrol resting in a diesel tank hurts nothing until it's dragged through your fuel system — by ignition priming, by the starter, or by driving. Keep it like that: leave the engine off then call Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and ways to make sure you don't repeat it.
Your engine and petrol in a diesel: what goes on
On its way through an engine, diesel has two tasks. Before it ignites, it lubricates — and then it ignites. Extremely fine clearances go into your injectors and your high-pressure pump, and just your diesel running through keeps their surfaces from grinding together.
Badly at the first, not at all at the second: that is petrol. The clattering comes from petrol being made not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication your system hinges on, and any pump running on that mix is wearing itself.
Seen together, they show what shape the trouble has. The damage is done by movement, not by contact. A tank with petrol in it is a fuel fault. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to the fuel injectors beyond it.
Four scenarios we see around Gaer: how serious is petrol in a diesel?
The best case there is: filled up, not once started. That petrol is in that tank and only your tank, and the task is a drain and a flush where the car sits. This is the one situation that can only truly take place on a forecourt, since anywhere else the car has been driven to get there.
A moment's running, or just your ignition on. Once primed, the fuel system has drawn petrol out of that tank as far as your filter and the fuel lines. Drain, flush, deal with your filter: still usually straightforward.
Some miles driven, and the pump has spent each of them labouring on diluted fuel. Miles is only half of that; how hard it was driven matters just as much. Either way the work runs to that tank, the lines, the filter and fresh fuel through the whole circuit. Driving the children to the local primary school is one sort of trip. Driving as far as Newport, under 3 miles away, makes a very different job — as does any mileage on the M4, under a mile from Gaer, with your engine running hard the whole time.
Driven until it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. That's the motor telling you its fuel has stopped behaving like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Gaer Road. A car pulled over soon very seldom has lasting damage, since the drain and the flush-through, which still come first, take care of it.
What Gaer 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'll be." Nothing is removed when you top up — that tank simply carries more of the same mixture. A diesel fuel system does not accept petrol by percentage in the way that guidance presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Smaller parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection count more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. Diesel in a petrol motor generally means a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually fires up, ticks over and drives away like nothing happened — all the while its pump is wearing. Being able to run isn't proof of being fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. None of what petrol diluted gets put back by it — and later, that tank still holds that petrol.
The next start sends petrol back round the pump from your lines and the fuel filter, where some of it sits once your engine has run. That's why a DIY tank drain does not sort it — a myth. And, a can of petrol filled by the roadside is genuinely dangerous.
Why petrol in a diesel occurs at all
A careless moment is rarely the cause, and nobody means to do it. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol motor at all. The forecourt makes it easy, and the error runs one way.
When routine and the car stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. Fuelling up in a rush en route to Pye Corner, with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Tiguan in front of you at the forecourt for its first tank — that's when. Throw in a back seat full of kids, a phone call or rain, and habit wins.
How to prevent petrol in a diesel on your next fill-up around Gaer
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a hint.
- In a car you do not know, look inside the flap over the filler or at the cap before the first fill: plenty of motors state the fuel type there.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- It seems silly and it works: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Put your phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a safety net, then keep reading the pump.
- As soon as you realise, stop: less petrol inside that tank means a weaker mix. What to do next doesn't change, though — still do not fire it up.
Gaer: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't fire it up, and don't turn your ignition on. If you are still on the forecourt — Tesco or anywhere else — ask the staff to help you push the vehicle clear of the pump. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Say so if it was AdBlue rather than petrol: it is a separate fault, with its own page for Gaer, because AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Gaer petrol in a diesel job cost more than the next
There's no honest single price for this, since the four scenarios above are four different tasks. What shifts the cost is chiefly which of them you are in. Where the car is matters too, and whether our van can safely get to it, after the ratio of petrol to what your tank holds.
What got in, how much, and if it has run — three questions we ask before quoting, not after, for precisely that reason. A range becomes a straight figure once those replies are in.
About Gaer, for a moment
Gaer is a suburban area located on the coast in south Wales, near the city of Newport. Gaer sits at an elevation of 51 metres, with views out over the surrounding landscape. Gaer is characterized by its predominantly semi-detached housing stock, and is situated close to nearby places such as Glasllwch and Maes-glas. Gaer is a relatively small community, with a population of around 5242 people.
Across Newport and around Gaer: fuel drain cover
Our vans answering petrol in diesel call-outs around Gaer, in the NP postcode area, also work the spots near it, Glasllwch, Stelvio and Maes-glas among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our engineers work, and the vehicle does not need to come to us.
In Gaer and still at the pump?
Nothing beats it: that is where you are. Leave it turned off, and ring.