Should You Worry? Petrol in a Diesel Car in East Hanney
Probably less than you are now — as long as nobody has started it. Until your ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank just rests there and does no harm. Which means the truthful reply to that first East Hanney question — "have I wrecked it?" — usually no. Petrol in Diesel is who to ring, with your motor left off, and so it remains that way. 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 don't do it again.
What petrol in a diesel does to the motor
Diesel does two tasks on its way through an engine. It ignites, and before it ignites it lubricates. Extremely fine clearances are built into your injectors and the high-pressure pump, and only your diesel flowing through keeps those surfaces from grinding together.
Of these two tasks, petrol manages the first poorly and the second never. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump on the mixture to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the rattling.
The shape of the problem is clear once you put those together. The harm is done by circulation, not by contact. Where the petrol is only inside the tank, it is a problem of fuel, nothing more. Whatever a worn pump sheds travels on, carried by your fuel, into the fuel injectors further along, which is why a pump that has been working on that petrol is where a mechanical problem starts.
How serious is petrol in a diesel? Four situations our technicians see around East Hanney
Filled up, and not started: nothing beats it. Just the tank has petrol in it, and so the job is clearing the tank and rinsing the fuel system where the car sits. This situation can only really occur at a forecourt: anywhere else, your car got there by being driven.
The ignition turned on, or a brief start. Petrol has left your tank and got to the filter and your lines, since the system has been bled. Still usually easy: drain, flush, and the fuel filter sorted.
Driven a couple of miles. Now the pump has spent those miles labouring on weakened fuel. The work is the tank, the fuel lines, the filter and fresh fuel through the entire system, and how hard the vehicle was driven counts as much as how far. Short trips, such as the school run to St James Church of England Primary School, Hanney, are one thing. Very different a second time: a run to Oxford, under 15 miles away, or any miles on the M4, under 15 miles from East Hanney, where the motor kept labouring hard.
Driven on till it complained — clattering, smoke, a ragged idle, a soft throttle. The engine is telling you your fuel is no longer acting like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Main Street. The fuel drain and flush-through still go first, and they sort it out: when a car is pulled over early, lasting damage is very uncommon.
What East Hanney people get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A bigger tank of the same mix is all it gives, because topping up takes out nothing. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. Protection counts more on current diesels, not less, because their fuel passes through smaller components at higher pressure.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally won't run, and so the motorist stops — and the harm stops with them. While the pump wears, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Running does not mean fine.
An outdated workaround for a distinct issue is behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has thinned stays thinned, and that petrol stays in that tank anyway.
Myth: "Drain that tank yourself and you're sorted." Once the engine has run, some of that petrol is no longer in that tank: it's in your filter and your lines, and it goes straight back through your pump on the next start. Besides, petrol emptied into a can by the road is genuinely risky.
How does petrol in a diesel occur?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol vehicle at all. So the error runs one way.
It occurs when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. Two cars on one driveway, one petrol, one diesel. Your ordinary forecourt, its pumps suddenly in a different order. A rushed fill on the way to Appleford with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. Add a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up in East Hanney: avoiding petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Trust the label on the pump, not the colour.
- Many vehicles state the fuel type inside the filler flap or on the cap, and so check it on the first fill in a vehicle you don't know.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a home has one of each. So mark it.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car gets its first tank. It seems daft. It works.
- Put your phone away. This is an easy mistake to make whilst you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for the rest. Count it as a backstop, then keep reading the pump.
- The moment you notice, stop: less petrol inside your tank means a weaker mix. What to do next does not change, though — still do not start it.
Put petrol in a diesel around East Hanney already?
Short and simple, then, is the order of things. Do not switch your ignition on, and do not fire it up. Still on the forecourt, at JET or anywhere else? Ask the staff to help you roll the vehicle clear of the petrol pump. Call 0333 366 0103 next, with three answers — your fuel, the approximate amount, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — East Hanney has a page all for it.
One petrol in a diesel job around East Hanney costs more than another. Why?
Four different tasks lie behind the four scenarios above — which is why there's no fair single quote. Chiefly, your cost shifts with which situation you are in. Two things come after that: the petrol that got in as a proportion of what that tank holds, then the spot your car is in and whether a van can reach it safely.
That's why our engineers ask three questions before pricing rather than after: what was put in, how much, and if it's run. With those answers, you get a straight figure rather than a range.
About East Hanney itself
East Hanney is a village in Oxfordshire, situated on the banks of the River Ock at an elevation of around 64 metres. East Hanney lies near the villages of West Hanney and Lyford, and is approximately 10 miles from Oxford. East Hanney has a population of around 790 people, with a predominance of detached housing. East Hanney is also within commuting distance of London, being around 55 miles from the capital.
Fuel drain cover across Oxfordshire, East Hanney included
Petrol in diesel call-outs around East Hanney — part of the OX postcode area — go to vans that likewise cover the spots around it, West Hanney, Lyford and Grove included. Our technicians drain wherever your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
East Hanney: still at the pump?
Then you are in the best place there is. Ring, and keep it turned off.