Petrol in a Diesel Car in Heavitree: How Worried Should You Be?
Less than you probably are, provided it has not been started. "Have I ruined it?" is the first question anyone in Heavitree asks, and the truthful answer is usually no, since petrol left in a diesel tank harms nothing until it is drawn through the system — by ignition priming, by the starter, or by being driven. Keep it that way: leave your engine off then phone Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and the way to make sure you never repeat it.
What petrol in a diesel does to the motor
On its way through a motor, diesel has two tasks. Oiling comes before burning; it does both. Your high-pressure pump and your injectors are designed to very fine tolerances, and the diesel passing through them is what keeps those surfaces from wearing down against one another.
The second task petrol doesn't do at all, and the first it does badly. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any knocking comes.
Put these together and the shape of the trouble is clear. Contact doesn't do the harm — movement does. Any tank with petrol in it is a fuel problem. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors beyond it.
How serious is petrol in a diesel? Four scenarios our engineers see around Heavitree
The best case there is: filled up, never started. At a forecourt, and truly only there, that petrol is still limited to the tank — because anywhere else the car was driven to reach it. The task is draining and rinsing on the spot.
Started for a second, or only your ignition on. The system has been primed, so petrol has left your tank and reached the fuel filter and the lines. Drain, flush, see to the filter: still usually straightforward.
A few miles driven, and your pump has spent each of them working on weakened fuel. How hard the car was driven counts as much as how far, and the work covers your tank, the fuel lines, your filter and fresh fuel through the entire circuit. Short trips, such as the school run to Woodwater Academy, are one matter. Very different once more: a trip to Exeter, under 3 miles away, or some mileage on the M5, under 3 miles from Heavitree, where your engine never stopped running hard.
Driven until it complained. Knocking, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is the engine reporting fuel that no longer runs like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Salters Road. The drain and flush-through still go first, and they deal with it: when a vehicle is pulled over early, long-term damage is very uncommon.
Myths Heavitree motorists hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. The idea behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. At higher pressure, through smaller parts: that is how a current diesel moves its fuel, so the protection counts for more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that fools people. Feed diesel to a petrol motor and it usually will not run, and so the motorist stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump grinds. Being able to run is not the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate issue. None of what petrol diluted gets put back by it — and later, your tank still holds that petrol.
The next start sends petrol back round the pump out of the fuel lines and your filter, where some of it ends up after the motor has been run. That's why draining the tank yourself doesn't sort it — a myth. Besides, petrol emptied into a can by the road is truly hazardous.
How does petrol in a diesel occur?
Carelessness is seldom the cause, and nobody means to do it. One way only, since of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol vehicle. That's how the forecourt makes it straightforward.
It takes place when routine and your car stop matching. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. A hurried fill on the way to Polsloe Bridge with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver accustomed to petrol: precisely when it takes place. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up around Heavitree: avoiding petrol in a diesel
- The label is what counts, and so check the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on each forecourt.
- The first fill in a strange car is the time to check the filler flap — inside it, or on the cap, many vehicles state the fuel they take.
- Label the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It sounds silly and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away then keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to reject a petrol nozzle, and add-on devices exist for the rest. Treat it as a backstop, and keep reading the petrol pump.
- Noticing it halfway? Stop at once. A weaker blend results from less petrol inside that tank, yet your next stage remains the same: do not fire it up.
Heavitree: already put petrol in a diesel?
Then the order of things is brief. Starting it is out, and so is turning on the ignition. The attendants on the forecourt — whether at BP itself or wherever you filled up — will usually help push it away from the petrol pump if you ask. Then call 0333 366 0103 and tell us what got in, about how much, and if it's run.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Heavitree, because AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel job in Heavitree costs more than another. Why?
An honest single price does not exist here: four situations, four separate jobs. Which of them you're in is mostly what moves the cost. Beyond that it is the proportion — how much petrol got in against how much the tank takes — and after that where your car is and whether a technician can reach it safely.
That is why we ask three questions before quoting rather than after: what got in, how much, and whether it has run. A range turns into a straight figure once those answers are in.
About Heavitree, for a moment
Heavitree is a suburban area located on the eastern edge of Exeter, situated near the River Exe in Devon. Heavitree sits at a relatively low elevation of around 25 metres, with nearby areas including Wonford, St Loyes, and Polsloe Bridge. Heavitree is characterized by its predominantly semi-detached housing stock, reflecting the typical residential development of the South West region. Heavitree is close to the city centre of Exeter, being only 1.7 miles away.
Heavitree and Devon: where our fuel drain cover runs
Heavitree sits in the EX postcode area, and the vans that answer petrol in diesel calls there work the places near it as well — Wonford, St Loyes and Polsloe Bridge among them. The car doesn't need to move to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Heavitree and still at the pump?
The best spot there is, then — that's where you are. Keep the vehicle switched off, and ring.