Should You Worry? Petrol in a Diesel Car in Garth
Provided it hasn't been started, worry far less than you likely are. Petrol sitting in a diesel tank does nothing to your motor till something draws it through the system — your ignition priming the pump, your starter, or the drive itself. So the truthful answer to the first question anyone in Garth asks, "have I wrecked it?", is generally no. Keep it like that: leave your engine off then ring Petrol in Diesel. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening a second time: that is the remainder of this page.
Inside the engine: what petrol in a diesel really does
On its way through a motor, diesel has two jobs. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure pump and the injectors from wearing down against one another is your diesel flowing through them — they're designed to very fine gaps.
Badly at the first, not at all at the second: that's petrol. It's runnier than diesel and removes the lubrication your fuel system rests on, so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Combined, those make the shape of the issue plain. The harm is done by circulation, not by contact. Petrol in the tank is a fuel issue. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
How serious is petrol in a diesel? Four situations our technicians see around Garth
Fuelled up, never started. The best case there can be. On a forecourt, and truly only there, that petrol is still limited to your tank — since anywhere else the vehicle was driven to reach it. The job is emptying and cleaning on the spot.
A moment's running, or merely the ignition on. Your system has been bled, and so petrol has left that tank and got to your filter and the lines. Normally nothing more than draining, purging and seeing to the fuel filter, and so still easy.
Those few miles on the road were your pump labouring on fuel diluted by petrol the whole way. How hard the vehicle was driven matters as much as how far, and the work takes in your tank, the lines, your filter and clean fuel through the entire circuit. Short trips, like the school run to the local primary school, are one matter. Getting as far as Bangor, under 25 miles away, makes a very different task — as does any miles on the Moreton Spur, over 50 miles from Garth, with the motor labouring hard all the way.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. That is your motor telling you its fuel no longer is behaving like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Borth Road. Permanent damage is very rare when a vehicle is pulled over early, and the drain and flush-through that still come first sort it out.
What Garth drivers get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. A fuller tank of the same mixture is all you get, because topping up takes out nothing. That advice presumes a diesel fuel system tolerates petrol by percentage. It does not.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Lubrication counts more on newer diesels, not less, since their fuel passes through more precise parts at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Diesel in a petrol motor generally leaves a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it normally fires up, ticks over and drives away like nothing has happened — all the while its pump wears. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the car home." It's an old fix for a separate fault. What petrol has thinned stays weakened, and the petrol stays inside that tank anyway.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in the fuel filter and lines, ready to go straight back through your pump on the next start. Also, a can of petrol filled at the kerbside is genuinely dangerous.
Why petrol in a diesel takes place at all
Nobody does it on purpose, and it's seldom carelessness. A diesel nozzle mostly will not fit a petrol motor, yet the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake simple, and only in one direction.
Routine and the car falling out of step is how it takes place. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. A familiar forecourt with the pumps in a different order. Filling up in a hurry on the way to Porthmadog, with a train to catch. A new-to-you diesel Volkswagen Tiguan, its first fuelling, and a driver used to petrol: precisely when it occurs. With rain, a call coming in, or children to deal with, your hand simply does what it always has.
Garth people: how to prevent petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on each forecourt. The label is what counts.
- In a motor you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of cars print the fuel type there.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a household 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.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and add-on devices are available for the rest. Treat it as a safety net, and keep checking the pump.
- Noticing it halfway? Stop at once. A weaker mix results from less petrol inside the tank, but your next step remains the same: don't start the vehicle.
Already put petrol in a diesel around Garth?
Then the order of things is brief. Leave it unstarted, with your ignition switched off as well. If you are still at the forecourt — BFL or anywhere else — ask the staff to help you push the car clear of the petrol pump. Then call 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
Corrosion and deposits form the trouble with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Garth page.
Why one petrol in a diesel job in Garth costs more than another
A fair single quote doesn't exist here: four situations, four separate tasks. Which of them you are in is chiefly what moves the cost. Beyond that it is the share — how much petrol was put in against how much the tank holds — and after that where your car is and whether a van can get to it safely.
Ahead of any quote, not after, come three queries: the fuel that got in, its volume, and if it's run. That is why. With the replies, there is a straight figure instead of a range.
About Garth
Garth is a small coastal suburban area in Gwynedd, Wales, situated near the towns of Porthmadog and Tremadog. Garth has a population of around 895 people and is characterized by its terraced housing. Garth sits at an elevation of 40 metres, looking out over the coastal landscape of northwest Wales. Garth is located approximately 21 miles from the city of Bangor and 195 miles from London.
Garth and Gwynedd: where our fuel drain cover reaches
Our teams answering petrol in diesel call-outs around Garth, in the LL postcode area, also work the spots near it, Porthmadog, Borth-y-Gest and Tremadog among them. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Still at the pump in Garth?
In that case, you could not be in a better position. Switched off it remains; then call.