Should You Worry? Petrol in a Diesel Car in Northend
Provided it hasn't been started, worry less than you likely are. "Have I ruined it?" is the first question anyone around Northend asks, and the honest answer is generally no, since petrol left in a diesel tank hurts nothing till it's drawn through the system — by ignition priming, by your starter, or by driving. Petrol in Diesel is who to phone, with the motor left off, and so it stays that way. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and the way to make sure you don't repeat it.
The motor and petrol in a diesel: what goes on
On its way through a motor, diesel has two jobs. Before it combusts, it protects — then it combusts. What keeps the surfaces inside the high-pressure pump and the fuel injectors from wearing against each other is your diesel passing through them — they're made to extremely fine clearances.
Of these two tasks, petrol handles the first poorly and the second not at all. It's thinner than diesel and removes the protection your fuel system depends on, and 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 reverse of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the issue is plain once you put those together. It is movement that does the harm, not contact. Where the petrol is only in your tank, it is an issue of fuel, nothing more. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to the fuel injectors beyond it.
Four scenarios our technicians see around Northend: how bad is petrol in a diesel?
Fuelled up, not once started. The best case there is. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With the petrol kept inside that tank alone, it's cleared and cleaned right where it stands, and nothing more is needed.
Started for a moment, or just your ignition on. Petrol has left that tank and got to your filter and the fuel lines, because the system has been bled. Still normally easy: drain, flush, and the fuel filter sorted.
Your pump now spent a couple of miles on weakened fuel — that is what driving the car does. Tank, lines, filter, then clean fuel run through the entire system: that is this work, and the way your car was driven matters as much as the distance. The school run to St Mary's Church of England Voluntary Aided Primary School is one matter. Very different a second time: a trip to Cambridge, under 15 miles away, or some miles on the M11, under 3 miles from Northend, where the engine never stopped labouring hard.
Driven on until it complained — clattering, smoke, an uneven idle, a soft throttle. That's your engine telling you its fuel has stopped acting like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on North End. What goes first is still the drain and flush-through, and that sorts it out, with permanent damage very uncommon if a vehicle is pulled over soon.
Northend drivers and the petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A fuller tank of the same mix is all it gives, since topping up removes nothing. Percentage isn't how a diesel fuel system tolerates petrol, whatever that guidance assumes.
Not so: a modern diesel copes with a bit of petrol. Rather, the reverse. A modern diesel sends its fuel through smaller parts at higher pressure, which makes the protection matter more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that catches drivers. The motorist of a petrol engine fed diesel usually stops, because it will not run, and the damage stops there. While your pump wears, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a separate fault. None of what petrol diluted is put back by it — and later, that tank still holds the petrol.
Myth: "Drain your tank yourself and you're sorted." After your engine has been run, some of the petrol is no longer in that tank: it is in your filter and the fuel lines, and it goes right back through the pump on your next start. Besides, petrol cleared into a can by the road is genuinely risky.
How it happens: petrol in a diesel
Nobody does it on purpose, and it is rarely carelessness. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
When routine and your car stop matching, it happens. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. A forecourt you know, only with its pumps laid out differently. A train to catch, and a rushed fill en route to Audley End. A new-to-you diesel Volkswagen Passat, its first fuelling, and a motorist used to petrol: exactly when it happens. With rain, a call coming in, or a car full of children to deal with, your hand simply does what it always has.
How to avoid petrol in a diesel at your next fill-up around Northend
- The label is what matters, and so read the pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- Many cars state the fuel inside your filler flap or on the cap, and so check it on the first fill in a vehicle you do not know.
- One of each in the home? Label the key to your diesel — a bright fob, a sticker — because intending to remember isn't enough.
- It seems silly and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Whilst you're thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a backstop at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol inside that tank makes a weaker mixture. What to do next does not change, though — still do not fire it up.
Already put petrol in a diesel in Northend?
Then the order of things is brief. Don't crank it, and don't switch the ignition on. Still at the forecourt, at Tesco or anywhere else? Ask the attendants to help you push the vehicle away from the pump. Next, 0333 366 0103. We'll ask what went in, roughly 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 Northend, since AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel job in Northend costs more than another
The four scenarios above are four separate jobs, so no single price for this would be honest. The situation itself does most of the work of moving your cost. Where the car is matters too, and whether a technician can safely reach it, after the proportion of petrol to what the tank holds.
That's why our technicians ask three queries before quoting instead of after: what got in, how much, and whether it's run. With those answers, you get a straight figure instead of a range.
About Northend itself
Northend is a small hamlet situated on the riverside in Essex, with an elevation of around 45 metres. Northend lies near the cities of Cambridge and Saffron Walden, and is also close to the villages of Littlebury and Audley End. Northend has a population of approximately 605 people and is characterised by predominantly detached housing. Northend is located 39.2 miles from London, making it a rural retreat within commuting distance of the capital.
Fuel drain cover across Essex, Northend included
Our vans answering petrol in diesel calls in Northend, in the CB postcode area, equally work the places around it, Littlebury, Audley End and Saffron Walden among them. You need not bring the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
At the petrol pump in Northend, still?
The best spot there is, then — that's where you are. Keep it turned off, and ring.