How Worried Should You Be? Petrol in a Diesel Car in Wadhurst
Far less than you likely are, provided it has not been started. Until your ignition primes your pump, the starter turns, or your car is driven, petrol in a diesel tank just sits there and does no harm. Which makes the honest reply to the first Wadhurst query — "have I wrecked it?" — usually no. Keep it that way: leave your engine off then ring Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and the way to make sure you never repeat it.
The motor and petrol in a diesel: what happens
Passing through a motor, diesel does two jobs at the same time. Before it burns, it protects — then it ignites. The high-pressure fuel pump and your injectors are made to extremely fine clearances, and your diesel passing through them is what keeps those surfaces from wearing down against each other.
Petrol handles the first task badly and the second not at all. The knocking comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection the system hinges on, and any pump running on that mix is wearing itself.
Together, those make the shape of the issue clear. Contact doesn't do the damage — movement does. Where the petrol is only inside the tank, it is a fault of fuel, nothing more. Whatever a worn pump sheds travels on, borne by your fuel, into the injectors further along, which is why a pump that has been working on the petrol is where a mechanical issue starts.
How serious is petrol in a diesel? Four scenarios our engineers see in Wadhurst
Fuelled but not once started — the best it gets. At a forecourt, and really only there, that petrol is still limited to that tank — since anywhere else the car was driven to get to it. The task is emptying and rinsing on the spot.
A brief spell of running, or just your ignition on. Petrol has left that tank and got to the filter and the fuel lines, since your system has been bled. Drain, flush, deal with the filter: still normally easy.
A couple of miles driven, and your pump has spent every one of them labouring on weakened fuel. How hard the vehicle was driven matters as much as how far, and this work takes in that tank, the fuel lines, the filter and fresh fuel through the whole circuit. Driving the kids to Wadhurst CofE Primary School and Nursery is one sort of trip. Driving as far as Brighton and Hove, under 50 miles away, makes a very different task — as does any mileage on the M26, under 25 miles from Wadhurst, with the engine labouring hard the whole time.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Pull up where you are — on the verge on Station Road, at the kerb, down a side road — and do not move it. A vehicle pulled over quickly very rarely has lasting damage, because the fuel drain and the flush, which still go first, sort it out.
What Wadhurst drivers get told about petrol in a diesel — and the stories in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — your tank simply carries more of the same blend. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice assumes.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." Protection matters more on newer diesels, not less, since their fuel runs through finer components at higher pressure.
Myth: "If it starts and drives, there is no harm done." This is the one that fools people. The motorist of a petrol engine fed diesel usually has no choice but to stop, since it will not run, and the damage stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump wears. Fine and running aren't the same at all.
An outdated workaround for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive it home." It does not put back what petrol has weakened, and that petrol is still in the tank later on.
The next start draws petrol back round your pump from your lines and the filter, where some of that ends up after the engine has been run. That is why a DIY tank drain does not sort it — a myth. On top of that, petrol drained into a can by the road is genuinely dangerous.
How does petrol in a diesel happen?
It is rarely carelessness, and nobody does it on purpose. A diesel nozzle mostly won't fit a petrol car, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and just in one direction.
It takes place when routine and the car stop matching. A motor that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. Racing for a train at the nearest station and filling up en route. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up around Wadhurst
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is only a clue.
- Check the filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in any motor you don't know.
- One of each in the household? Mark the key to your diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds silly and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put your phone away and keep your mind on the petrol pump.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that will not accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Less petrol makes a weaker blend, and so stop the moment you realise — though remembering that the next stage is unchanged. It is still not to start the car.
Already put petrol in a diesel in Wadhurst?
The order of things is short, then. Starting it is out, and so is turning on your ignition. If you are still at the forecourt — Wadhurst Service Station or anywhere else — ask the staff to help you push the car away from 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 instead of petrol: it's a different problem, with its own page for Wadhurst, because AdBlue brings corrosion and deposits rather than lost protection.
One petrol in a diesel job in Wadhurst costs more than another. Why?
The four situations above are four separate jobs, so no single quote for this would be honest. What moves your cost is chiefly which of them you are in. Where your car is counts too, and whether a van can safely get to it, after the ratio of petrol to what that tank takes.
Three questions come first, before any quote, instead of after — what went in, how much, has it run — and this is the reason. With the replies, you get a straight figure rather than a range.
About Wadhurst itself
Wadhurst is a small town in East Sussex, situated in a rural area at an elevation of around 154 metres. Wadhurst lies approximately 36 miles south of London and 26 miles north of Brighton and Hove, with nearby villages including Durgates, Sparrows Green, and Primmers Green. Wadhurst has a population of around 3121 people and is characterised by predominantly detached housing.
Fuel drain cover in Wadhurst and across East Sussex
Durgates, Sparrows Green and Primmers Green are among the locations around Wadhurst that the same vans work, answering petrol in diesel calls across Wadhurst's TN postcode area. No need to move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots we drain.
Still at the pump around Wadhurst?
Then, you couldn't be in a better spot. Keep it off. Call.