How Worried Should You Be? Petrol in a Diesel Car in Upper Hartwell
Probably less than you already are — as long as nobody has started the car. Till the ignition primes your pump, the starter turns, or your car is driven, petrol in a diesel tank just sits there and does nothing. Which means the honest reply to the first Upper Hartwell question — "have I ruined it?" — usually no. Keep it like that: leave your motor off and phone Petrol in Diesel. Below, this page sets out what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the motor?
Passing through a motor, diesel is doing two things at the same time. Oiling comes before burning; it does both. Made to very fine tolerances, the injectors and your pump rely on your diesel moving through them to stop their surfaces wearing against one another.
The second task petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump on the blend to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the rattling.
The shape of the issue is plain when you put those together. The harm is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel issue. After the pump has been running on that petrol, a mechanical issue has started: whatever is shed by a pump that's wearing down is carried downstream to the injectors with the fuel.
Petrol in a diesel around Upper Hartwell: how bad is it? Four cases
Filled up, never started. The best case there can be. That petrol is inside your tank and only the tank, and the job is a drain and a flush where the vehicle stands. This is the one scenario that can only really happen at a forecourt, since anywhere else the car has been driven to get there.
Started for a second, or just your ignition on. Once primed, your system has drawn petrol from the tank as far as the fuel filter and the lines. Usually little more than draining, cleaning and sorting the filter, so still easy.
A few miles driven, and your pump has spent each of them labouring on thinned fuel. Tank, lines, filter, then fresh fuel run through the entire system: that is this work, and the way your car was driven matters as much as the mileage. Driving the kids to Stone Church of England Combined School is one sort of trip. A run as far as Milton Keynes, under 25 miles away, is a very different job. So is any mileage on the M40, under 10 miles from Upper Hartwell, where your engine has been labouring hard throughout.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone ragged. What you are hearing is your engine reporting fuel that no longer runs like diesel. Leave it where it stops: a lay-by, a side street, the verge on Round Hill. What comes first is still the fuel drain and flush-through, and that deals with it, with permanent damage very unusual if a car is pulled over soon.
Upper Hartwell motorists and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Topping up takes out nothing; it gives you a fuller tank of the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that guidance assumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the reverse. At higher pressure, through smaller parts: that's 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 drivers. A petrol engine fed diesel normally won't run, and so the motorist stops and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Fine and running aren't the same at all.
Not so: a two-stroke additive lets you to drive home. It is an old workaround, supposed for another fault. None of what petrol thinned gets put back by it — and afterwards, that tank still holds the petrol.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the filter and lines, waiting to go straight back through the pump at the next start. Clearing petrol into a can by the kerbside is also really risky.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol vehicle at all. The forecourt makes it simple, and the slip runs one way.
When routine and your car stop matching, it happens. A vehicle that's new to you — hired, on loan as a courtesy car, or just bought. Two vehicles on one driveway, one petrol, one diesel. A familiar forecourt with the pumps in a different order. Rushing for a train outside Aylesbury and filling up en route. A new-to-you diesel Volkswagen Passat, its first fuelling, and a motorist accustomed to petrol: precisely when it takes place. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Upper Hartwell motorists: how to prevent petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before the first fill: many motors state the fuel there.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, in a household with one of each.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new vehicle, say "diesel" aloud. Silly, perhaps, but it does the trick.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Less petrol makes a weaker mixture, and so stop as soon as you notice — though remembering that your next stage is unchanged. It's still not to start the car.
Upper Hartwell: already put petrol in a diesel?
Short and simple, then, is the order of things. Do not turn your ignition on, and don't start it. If you are still on the forecourt — Spot Fuel or anywhere else — ask the staff to help you push the car away from the pump. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it has been run.
Say so if it was AdBlue rather than petrol: it's a separate problem, with its own page for Upper Hartwell, because AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel task around Upper Hartwell costs more than another
An honest single price does not exist here: four situations, four separate tasks. Which of them you are in is mostly what moves your cost. Two things follow that: the petrol that got in as a proportion of what your tank takes, then the spot the car is in and whether a technician can reach it safely.
What went in, how much, and whether it has run — three queries our technicians ask before quoting, not after, for exactly that reason. A range turns into a straight figure once the replies are in.
About Upper Hartwell itself
Upper Hartwell is a suburban area in Buckinghamshire, situated inland at an elevation of around 105 metres. Upper Hartwell lies near the villages of Stone and Lower Hartwell, and is also close to Sedrup, with Milton Keynes being the nearest city. Upper Hartwell is characterized by its predominantly detached housing stock, and is home to a population of approximately 1640 residents. Upper Hartwell is located about 37.4 miles from London, making it a commuter base for those working in the capital.
Across Buckinghamshire and in Upper Hartwell: fuel drain cover
Upper Hartwell sits in the HP postcode area, and the teams that answer petrol in diesel calls there work the locations around it as well — Stone, Lower Hartwell and Sedrup among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers drain, and the vehicle doesn't need to move to us.
Upper Hartwell: still at the petrol pump?
Then you are in the best position there is. Keep it off. Call.