How Worried Should You Be? Petrol in a Diesel Car in Seafield
Not started? Then less worried than you probably feel. Petrol sitting in a diesel tank does nothing to the motor until something draws it through the system — the ignition priming the pump, your starter, or driving itself. So the honest answer to the first question everyone around Seafield asks, "have I wrecked it?", is normally no. Leave the engine off then call Petrol in Diesel — that keeps it like that. The remainder of this page covers what petrol really does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
Inside the motor: what petrol in a diesel does
Two jobs fall to diesel on its route through a motor. It protects first, and only then does it burn. What stops the surfaces inside the high-pressure pump and the injectors from wearing against one another is the diesel flowing through them — they're built to extremely fine gaps.
Petrol handles the first task poorly and the second not at all. A pump running on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the lubrication your fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the clattering starts.
Together, those leave the shape of the problem clear. It is movement that does the damage, not contact. All a tank with petrol in it amounts to is a fuel issue. Once your pump has been working on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing is carried onward to the injectors with the fuel.
How serious is petrol in a diesel? Four situations our engineers see around Seafield
The best case there can be: filled up, never started. The petrol is inside the tank and only that tank, and the job is a drain and a flush where your car stands. This is the one situation that can only truly occur at a forecourt, because anywhere else the vehicle has been driven to get there.
A brief spell of running, or merely the ignition on. Petrol has left your tank and reached your filter and your lines, since the system has been primed. Usually nothing more than draining, flushing and sorting the fuel filter, and so still easy.
A couple of miles driven, and the pump has spent each of them labouring on thinned fuel. The work is your tank, your lines, the filter and fresh fuel through the whole system, and how hard your car was driven counts as much as how far. Driving the kids to the local primary school is one sort of trip. Very different a second time: a trip to Edinburgh, under 10 miles away, or any distance on the M8, under 10 miles from Seafield, where the motor kept running hard.
Driven until it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the engine reporting fuel that no longer behaves like diesel. Stop where you are — on the verge on Seafield Moor Road, at the kerb, down a side road — and do not move it again. What comes first is still the fuel drain and flush, and that sorts it out, with lasting damage very unusual if a car is pulled over soon.
Seafield motorists and the petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It doesn't. A bigger tank of the same mix is all it gives, since topping up takes out nothing. That guidance supposes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Any petrol engine fed diesel normally will not run, and so the motorist stops and the damage stops with them. Feed petrol to a diesel and it normally starts, idles and pulls away like nothing happened — all the while its pump is wearing. Fine and running aren't the same thing.
An old workaround for a different issue is behind this one. Myth: "Add some two-stroke oil and drive it home." None of what petrol thinned is put back by it — and later, that tank still contains that petrol.
Myth: "Drain the tank yourself and you're sorted." After your engine has been run, some of the petrol is no longer in the tank: it's in your filter and the fuel lines, and it goes right back through your pump on the next start. It is also genuinely risky to drain petrol into a can by the roadside.
How does petrol in a diesel occur?
Nobody does it on purpose, and it's seldom carelessness. A diesel nozzle mostly will not fit a petrol motor, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error straightforward, and only in one direction.
When habit and the vehicle stop matching, it happens. Hire cars, courtesy cars, and motors that are new to you. A household with one petrol and one diesel on the driveway. A forecourt you know, only with its pumps laid out differently. Fuelling up in a hurry en route to Slateford, with a train to catch. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. With rain, a call arriving, or children to deal with, the hand simply does what it has always done.
Avoiding petrol in a diesel next time you fill up around Seafield
- Green for unleaded and black for diesel is usual in the UK — but not on each forecourt. Go by the label on the pump, not the colour.
- The first fill in an unfamiliar motor is the time to check your filler flap — on it, or on the cap, plenty of vehicles state the fuel they take.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, for a house with one of each.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It seems silly and it does the trick.
- Mistakes like this are straightforward to make while your mind is on something else, so the phone goes away.
- Add-on devices exist for motors without one, and some diesels are built with a filler that won't take a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- The moment you realise, stop: less petrol in that tank makes a weaker mixture. What to do next doesn't change, though — still don't start the vehicle.
Petrol already in a diesel around Seafield? Begin here
Then the order of things is brief. Starting it is out, and so is switching on the ignition. If you are still on the forecourt — Asda or anywhere else — ask the attendants to help you push the vehicle clear of the petrol pump. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it's been run.
Say so if it was AdBlue rather than petrol: it's a different fault, with its own page for Seafield, since AdBlue brings corrosion and deposits rather than lost lubrication.
One petrol in a diesel task in Seafield costs more than another. Why?
There's no honest single quote for this, because the four scenarios above are four separate tasks. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that went in as a proportion of what that tank takes, then the spot your car is in and whether a van can get to it safely.
That is why our technicians ask three queries before quoting rather than after: what got in, how much, and if it has run. A range becomes a straight figure when those answers are in.
About Seafield itself
Seafield is a small hamlet situated on the riverside in Midlothian, with a mix of semi-detached housing and a population of around 774 residents. Seafield sits at an elevation of approximately 170 metres, close to the nearby settlements of Bilston, Bush, and Boghall. Seafield is located near Edinburgh, Scotland's capital city, which is about 5.8 miles away. Seafield occupies a scenic spot in the Midlothian countryside, with the River North Esk flowing nearby.
Seafield and Midlothian: where our fuel drain cover reaches
The vans answering petrol in diesel jobs in Seafield, in the EH postcode area, also work the locations near it, Bilston, Bush and Boghall included. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
Still at the petrol pump around Seafield?
No position is better: that's where you are. Keep it switched off, and ring.