Coupar Angus: Petrol in a Diesel Car? How Worried to Be
Likely less than you are now — as long as nobody has started the vehicle. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through the fuel system — the ignition priming your pump, your starter, or the drive itself. So the truthful answer to the first query anyone around Coupar Angus asks, "have I wrecked it?", is normally no. Petrol in Diesel is who to call, with the motor kept off, and so it stays that way. What petrol actually does to a diesel, how to gauge how far it's travelled, and how to keep it from happening again: that's the remainder of this page.
Inside your engine: what petrol in a diesel does
On its way through a motor, diesel has two jobs. It protects first, and after that does it burn. The high-pressure pump and your injectors are made to very fine clearances, and the diesel passing through them is what stops those surfaces from wearing against one another.
Badly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on the mixture wearing itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
Taken together, they make clear the shape the issue has. Contact does not do the harm — movement does. Any tank with petrol in it is a fuel fault. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with your fuel to your injectors further on.
Petrol in a diesel in Coupar Angus: how serious is it? Four situations
Fuelled but never started — as good as it gets. That petrol is inside that tank and only the tank, and the job is a drain and a flush where the vehicle sits. This is the one situation that can only really occur on a forecourt, as anywhere else the vehicle has been driven to get there.
Your ignition turned on, or a short start. Petrol has come out of the tank and reached the fuel filter and the fuel lines, since the system has been bled. Still usually simple: drain, flush, and your filter dealt with.
Your pump now worked a few miles on weakened fuel — that's what driving it meant. The work is your tank, the fuel lines, your filter and fresh fuel through the whole circuit, and how hard the car was driven counts as much as how far. On the school run to the local primary school, the mileage is short. Very different once more: a run to Perth, under 15 miles away, or some miles on the M90, under 15 miles from Coupar Angus, where your engine never stopped working hard.
Clattering, a ragged idle, smoke, a throttle gone soft: driven until it complained. The fuel isn't behaving like diesel any more, and your motor is saying so. Whether it's the verge on Hay Street, a lay-by or a side road, stop where you are then leave it. What goes first is still the drain and flush, and that deals with it, with lasting damage very uncommon when a car is stopped quickly.
Stories Coupar Angus people hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — the tank just holds more of the same blend. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through finer components: that's how a newer diesel handles its fuel, and so the protection counts more, not less.
One myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally leaves a motor that won't run: the motorist stops, and so does the damage. Feed petrol to a diesel and it normally fires up, idles and pulls away like nothing happened — all the while its pump is wearing. Fine and running aren't the same thing.
Not so: a two-stroke additive makes it safe to drive home. It was an old fix, supposed for another issue. None of what petrol diluted gets put back by it — and later, the tank still contains the petrol.
The next start sends petrol back round the pump from your lines and the fuel filter, where some of that sits after the engine has run. That's why a DIY tank drain doesn't sort it — a myth. Clearing petrol into a can at the roadside is also really dangerous.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol motor. That is how the forecourt makes it simple.
Routine and your car falling out of step is how it occurs. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps laid out differently. A hurried fill on the way to Invergowrie with a train to catch. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. With rain, a call arriving, or a car full of children to deal with, the hand just does what it always has.
Preventing petrol in a diesel next time you fill up around Coupar Angus
- Check 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 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 there.
- One of each in the household? Label the key to your diesel — a coloured fob, a sticker — because intending to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It sounds daft. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to block a petrol nozzle, and add-on devices exist for motors without one. They are a safety net, not a reason to stop reading the petrol pump.
- Less petrol means a weaker blend, so stop as soon as you notice — while remembering that the next stage is unchanged. It's still not to start it.
Coupar Angus: already put petrol in a diesel?
Short and simple, then, is the order of things. Never crank it, and don't switch the ignition on. The attendants at the forecourt — whether at Shell itself or wherever you filled up — will normally help roll it away from the petrol pump if you ask. What went in, roughly how much, and whether it's run: tell us those when you ring 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a different fault — Coupar Angus has a page just for it.
What makes one Coupar Angus petrol in a diesel job cost more than the next
An honest single price does not exist here: four situations, four separate jobs. Mostly, the cost shifts with which one you're in. Where your car is counts too, and whether a technician can safely reach it, after the proportion of petrol to what the tank holds.
That is why our technicians ask three queries before quoting instead of after: what got in, how much, and if it has run. The replies turn a range into a straight figure.
About Coupar Angus
Coupar Angus is a town situated on the banks of the River Isla in Perth and Kinross, with a population of around 2138 people. Coupar Angus has a mix of housing types, but semi-detached homes are the most common. Coupar Angus is located near several smaller communities, including Princeland, Markethill, and North Corston. Coupar Angus sits at an elevation of 58 metres, approximately 12 miles from the city of Perth.
Fuel drain cover in Coupar Angus and across Perth and Kinross
Princeland, Markethill and North Corston are among the spots near Coupar Angus that the same teams work, answering petrol in diesel jobs across Coupar Angus's PH postcode area. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
Still at the petrol pump in Coupar Angus?
The best spot there is, then — that is where you are. Keep it off. Call.