Heathcote: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, you can worry less than you probably are. "Have I ruined it?" is the first thing anyone around Heathcote asks, and the honest answer is normally no, because petrol left in a diesel tank hurts nothing until it's drawn through your fuel system — by ignition priming, by your starter, or by being driven. Keep it that way: leave the motor off then phone Petrol in Diesel. The remainder of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
The motor and petrol in a diesel: what goes on
Passing through an engine, diesel is doing two jobs at once. It ignites, and before it combusts it protects. Extremely fine tolerances are built into the injectors and your high-pressure pump, and only the diesel flowing through keeps those surfaces from grinding together.
Of those two jobs, petrol handles the first badly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on the mixture wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the clattering.
The shape of the trouble is clear once you put those together. Not contact but movement is what does the harm. Petrol in the tank is a fuel problem. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the fuel injectors further on.
Heathcote, petrol in a diesel: four situations, from mild to serious
Fuelled, and not started: nothing beats it. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it is emptied and flushed on the spot, and nothing more is needed.
Started for a moment, or only the ignition on. Once primed, the system has drawn petrol from your tank up to the fuel filter and your lines. Drain, flush, see to the filter: still normally simple.
Those few miles on the road meant the pump working on fuel thinned by petrol throughout. How hard your car was driven counts as much as how far, and the work takes in the tank, your lines, your filter and fresh fuel through the whole circuit. The school run to Heathcote Primary School is one matter. Any distance on the M40, under 3 miles from Heathcote, means the motor has worked hard throughout, and a run to Coventry, under 10 miles away, makes a very different task as well.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The fuel is not acting like diesel any more, and the motor is saying so. Whether it is the verge on Gallagher Way, a lay-by or a side road, stop there then leave it. What comes first is still the drain and flush, and that sorts it out, with permanent damage very uncommon if a car is stopped soon.
What Heathcote motorists get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed when you top up — that tank just holds more of the same blend. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. A newer diesel runs its fuel through more precise components at higher pressure, which makes the protection count more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools motorists. Feed diesel to a petrol engine and it generally won't run, and so the driver stops — and the damage stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, while the pump wears. Fine and running aren't the same at all.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. It doesn't put back what petrol has diluted, and that petrol is still in your tank after that.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol lies in the filter and lines, waiting to go straight back through the pump on your next start. And, a can of petrol filled by the roadside is genuinely dangerous.
Why petrol in a diesel happens so easily
It is rarely carelessness, and no one does it on purpose. A diesel nozzle mostly will not go into a petrol vehicle, but the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and only in one direction.
It takes place when routine and the car stop matching. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps now in a different order. A train to catch, and a hurried fill en route to Leamington Spa. The first fill-up in a diesel BMW 3 Series after years of driving petrol is exactly the moment it takes place. With rain, a call coming in, or children to deal with, the hand simply does what it has always done.
Heathcote people: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a clue.
- The first fill in an unfamiliar motor is the time to check your filler flap — on it, or on the cap, many vehicles state which fuel to use.
- Mark the key. In a home 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 your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It seems silly and it works.
- 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 won't take a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- The moment you notice, stop: less petrol inside the tank means a thinner mix. What to do next doesn't change, though — still don't fire it up.
Petrol already in a diesel around Heathcote? Start here
Short and simple, then, is the order of things. Never crank it, and don't turn the ignition on. Yet at the forecourt, at Sainsbury's or anywhere else? Ask the staff to help you roll the car clear of the pump. Call 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and whether it has run.
Say so if it was AdBlue instead of petrol: it's a separate issue, with its own page for Heathcote, because AdBlue brings corrosion and deposits instead of lost lubrication.
One petrol in a diesel job around Heathcote costs more than another. Why?
Four different tasks sit behind the four scenarios above — which is why there is no fair single price. Mostly, your cost shifts with which one you're in. Where your car is matters too, and whether a van can safely get to it, after the ratio of petrol to what that tank takes.
Three queries come first, before any quote, instead of after — what went in, how much, has it run — and that is the reason. The replies turn a range into a straight figure.
About Heathcote itself
Heathcote is a suburban area in Warwickshire, situated on the riverside at an elevation of 66 metres, with detached housing being the predominant type of accommodation. Heathcote lies approximately 9.9 miles from Coventry and 80.2 miles from London, making it a commuter-friendly location. Heathcote is surrounded by nearby places such as Myton, Whitnash, and Tachbrook Mallory, and has a population of around 5078 residents. Heathcote's riverside setting provides a unique character to the area.
Across Warwickshire and in Heathcote: fuel drain cover
Petrol in diesel calls around Heathcote — part of the CV postcode area — go to teams that also cover the spots about it, Myton, Whitnash and Tachbrook Mallory among them. The car doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump around Heathcote, right now?
Then, you could not be in a better place. Keep it off. Call.