How Worried Should You Be? Petrol in a Diesel Car in Hemblington Corner
Probably less than you are now — provided no one has started the vehicle. "Have I wrecked it?" is the first thing anyone around Hemblington Corner asks, and the truthful answer is usually no, because petrol resting in a diesel tank harms nothing until it's dragged through your fuel system — by ignition priming, by the starter, or by being driven. Keep it like that: leave the engine off then call Petrol in Diesel. 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 never repeat it.
Petrol in a diesel: what does it do to the motor?
Two jobs fall to diesel on its journey through a motor. It lubricates to begin with, and only then does it burn. Extremely fine clearances are built into your injectors and your high-pressure pump, and only your diesel flowing through keeps their surfaces from grinding together.
Petrol does the first task poorly and the second not at all. The knocking comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication your system rests on, and any pump running on such a mixture is wearing itself.
Seen together, they make clear the shape the problem takes. Not contact but movement is what causes the harm. Petrol in the tank is a fuel problem. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors further along, which is why a pump that has worked on the petrol is where a mechanical issue begins.
Four situations our technicians see around Hemblington Corner: how serious is petrol in a diesel?
Fuelled up, never started. The best case there can be. Just the tank has petrol in it, and so the task is emptying that tank and cleaning your system where the car stands. This situation can only really take place on a forecourt: anywhere else, the car got there by being driven.
Your ignition turned on, or a brief start. Once primed, the system has drawn petrol out of that tank up to your filter and your lines. Still generally easy: drain, flush, and your filter dealt with.
Those few miles driven were the pump running on fuel diluted by petrol the whole way. Tank, lines, filter, then fresh fuel put through the whole circuit: that is the work, and the way the car was driven matters as much as the mileage. On the school run to Hemblington Primary School, the miles is short. Very different a second time: a trip to Norwich, under 10 miles away, or some miles on the M11, over 50 miles from Hemblington Corner, where your engine kept labouring hard.
Driven till it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer behaving like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Hemblington Hall Road. What goes first is still the fuel drain and flush, and that sorts it out, with lasting damage very unusual when a vehicle is pulled over soon.
Stories Hemblington Corner drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Topping up takes out nothing; it gives you a fuller tank of the same mixture. That guidance supposes a diesel fuel system handles petrol by percentage. It doesn't.
Not so: a modern diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through finer parts: that is how a newer diesel handles its fuel, so the protection matters more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that will not run: the motorist stops, and so does the harm. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump grinds. Running isn't the same as fine.
An old fix for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol weakened is put back by it — and afterwards, that tank still holds the petrol.
Myth: "Drain that tank yourself and you're sorted." After the motor has run, some of that petrol is no longer in the tank: it's in the filter and the fuel lines, and it goes right back through the pump at your next start. Draining petrol into a can at the kerbside is also really hazardous.
How does petrol in a diesel happen?
It is rarely carelessness, and no one does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
Habit and the car falling out of step is how it occurs. A new vehicle, a hire car or a courtesy car. Two vehicles on one drive, one petrol, one diesel. Your usual forecourt, its pumps now in a different order. A rushed fill on the way to Brundall with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Preventing petrol in a diesel next time you fill up in Hemblington Corner
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- Many motors state the fuel inside the filler flap or on the cap, so check there on your first fill in a vehicle you don't know.
- One of each in the home? Label the key to your diesel — a bright fob, a sticker — because intending to remember is not enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems daft and it works.
- Mistakes like this are easy to make while your mind is on something else, and so your phone goes away.
- Add-on devices are available for motors without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop the moment you notice. Less petrol in that tank makes a thinner mix. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Hemblington Corner?
The order of things is short, then. Leave it unstarted, with the ignition off too. If you are still at the forecourt — Shell or anywhere else — ask the staff to help you roll it away from the pump. Call 0333 366 0103 next, with three facts — the fuel, the approximate amount, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Hemblington Corner has a page all for it.
One petrol in a diesel task in Hemblington Corner costs more than another. Why?
An honest single price doesn't exist here: four scenarios, four separate jobs. What moves the cost is mostly which of them you're in. Where your car is matters too, and whether a technician can safely reach it, after the share of petrol to what that tank holds.
Three queries come first, before any quote, instead of after — what was put in, how much, has it run — and this is the reason. Those replies are what turn a range into one firm number.
About Hemblington Corner
Hemblington Corner is a suburban area located in Norfolk, situated approximately 6.9 miles from Norwich and 103.7 miles from London. Hemblington Corner sits at an elevation of 19 metres, amidst the gently rolling countryside of eastern England. Hemblington Corner is characterized by its predominantly detached housing stock, with nearby villages including Hemblington, Pedham, and Blofield Heath.
Across Norfolk and in Hemblington Corner: fuel drain cover
Hemblington, Pedham and Blofield Heath are among the places around Hemblington Corner that the same teams work, answering petrol in diesel call-outs across Hemblington Corner's NR postcode area. Our engineers drain where the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the pump around Hemblington Corner?
Then, you couldn't be in a better position. Switched off it stays; then phone.