Should You Worry? Petrol in a Diesel Car in Brasside
Far less than you probably are, provided it hasn't been started. "Have I ruined it?" is the first question everyone around Brasside asks, and the truthful answer is usually no, because petrol left in a diesel tank harms nothing until it's drawn through the fuel system — by ignition priming, by your starter, or by driving. Keep it like that: leave your motor off and call Petrol in Diesel. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
The engine and petrol in a diesel: what goes on
Two jobs fall to diesel on its route through a motor. Before it burns, it lubricates — and then it ignites. Made to very fine gaps, the fuel injectors and your pump rely on your diesel flowing through them to keep their surfaces from wearing against one another.
The second task petrol doesn't do at all, and the first it does poorly. It is thinner than diesel and takes away the lubrication your fuel system hinges on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the clattering comes from.
Combined, those leave the shape of the issue plain. It is circulation that does the damage, not contact. A tank with petrol in it is a fuel problem. Once the pump has been labouring on that petrol, a mechanical issue has started: whatever is shed by a pump that's wearing is carried onward to your injectors with your fuel.
Brasside, petrol in a diesel: four cases, from mild to serious
The best case there can be: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it's cleared and cleaned right where it stands, and nothing more is needed.
The ignition switched on, or a short start. Your system has been bled, and so petrol has left your tank and got to the fuel filter and your lines. That is usually still a straightforward task — a drain, a flush, and the filter dealt with.
Your pump has spent a few miles on thinned fuel — that's what driving the car meant. Tank, lines, filter, then clean fuel put through the whole circuit: that is this work, and the way your car was driven matters as much as the miles. The school run to Finchale Primary School is one matter. A run as far as Durham, under 3 miles away, is a very different job. So is any miles on the A1(M), under 3 miles from Brasside, where your engine has been running hard throughout.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you your fuel is no longer acting like diesel. Pull up wherever you are — the verge on Rowan Drive, a lay-by, a side street — and leave the car there. Permanent damage is very rare if a car is pulled over early, and the drain and flush that still go first deal with it.
Stories Brasside drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you're left with a fuller tank, still the same mixture. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
"Newer diesels can handle a little petrol" — a myth, and closer to the reverse. At higher pressure, through finer parts: that is how a modern diesel moves its fuel, so the lubrication matters for more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up most motorists than any other. The driver of a petrol engine fed diesel usually stops, since it will not run, and the damage stops there. While the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Fine and running aren't the same at all.
An old fix for a distinct issue lies behind this one. Myth: "Add some two-stroke oil and drive it home." None of what petrol diluted gets put back by it — and afterwards, the tank still contains that petrol.
Myth: "Drain that tank yourself and you're sorted." Once the motor has been run, some of that petrol is no longer in that tank: it is in the fuel filter and the lines, and it goes right back through the pump on the next start. Draining petrol into a can at the roadside is also genuinely hazardous.
How it happens: petrol in a diesel
A careless moment is seldom the cause, and no one means to do it. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol car at all. So the error runs one way.
It happens when routine and your car stop matching. A vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the driveway. A familiar forecourt with the pumps in a different order. Rushing for a train at Durham and fuelling up en route. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Audi A4 for the first time. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Next time you fill up in Brasside: avoiding petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what counts.
- Many vehicles state the fuel inside your filler flap or on the cap, and so check it on your first fill in any car you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, for a house with one of each.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It works.
- Tuck the phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices exist for motors without one, and some diesels come with a filler that will not take a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol inside your tank makes a thinner mix. What to do next doesn't change, though — still don't fire it up.
Petrol already in a diesel in Brasside? Begin here
Then the order of things is short. Do not turn the ignition on, and do not start it. The attendants at the forecourt — whether at Sainsbury's itself or wherever you filled up — will normally help push it away from the petrol pump if you ask. Then phone 0333 366 0103 and tell us what went in, roughly how much, and whether it's run.
If it was AdBlue rather than petrol, say so. That's a different issue — corrosion and deposits and not lost protection — and it has its own page for Brasside.
One petrol in a diesel task in Brasside costs more than another. Why?
There is no fair single quote for this, since the four situations above are four separate tasks. What shifts the cost is chiefly which of them you are in. The proportion counts next, meaning how much of the tank is petrol, followed by the position of your car and whether getting to it is safe for our van.
What got in, how much, and if it's run — three questions our engineers ask before quoting, not after, for exactly that reason. Their replies are what change a range into one firm number.
About Brasside, for a moment
Brasside is a suburban area located near the city of Durham, sitting at an elevation of 57 metres in the inland countryside of County Durham. Brasside is characterized by its predominantly semi-detached housing stock, which reflects the typical residential development of the region. Brasside is close to several nearby places, including Newton Hall, Pity Me, and Framwellgate Moor, and is situated approximately 2.2 miles from Durham city centre. Brasside has a population of around 2063 residents, according to approximate estimates.
Brasside and Durham: where our fuel drain cover runs
Petrol in diesel call-outs in Brasside — part of the DH postcode area — go to teams that also cover the places about it, Newton Hall, Pity Me and Framwellgate Moor included. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our technicians drain, and the vehicle does not need to move to us.
Still at the petrol pump in Brasside?
The best place there is, then — that's where you are. Keep it off. Ring.