Hales Park: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you probably feel. Everyone in Hales Park begins with "have I ruined it?", and the honest answer is normally no: petrol left in that tank of any diesel remains harmless till priming, cranking or driving draws it into your fuel system. Leave your engine off then ring Petrol in Diesel — that is how you keep it that way. Below, this page sets out what petrol actually does inside a diesel, how far it might have gone, and how to stop it happening to you again.
What petrol in a diesel does to the motor
Two tasks fall to diesel on its route round a motor. Before it burns, it lubricates — and then it ignites. Built to very fine clearances, your injectors and the pump rely on the diesel moving through them to stop their surfaces wearing against one another.
Of those two tasks, petrol manages the first poorly and the second not at all. A pump running on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that is where the rattling comes.
Together, those leave the shape of the problem clear. It's movement that causes the harm, not contact. Petrol in a tank is a fuel issue. Whatever a worn pump sheds travels on, borne by the fuel, into the fuel injectors further along, which is why a pump that has worked on that petrol is where a mechanical issue begins.
Petrol in a diesel around Hales Park: how bad is it? Four situations
Filled up, and never started: nothing beats it. At a forecourt, and really only there, the petrol is still limited to your tank — since anywhere else the vehicle was driven to get to it. The job is draining and flushing on the spot.
A moment's running, or just the ignition on. Your system has been primed, so petrol has left the tank and got to the filter and your lines. Drain, flush, deal with the fuel filter: still usually simple.
Driven a few miles. Now the pump has spent these miles labouring on weakened fuel. Tank, lines, filter, then clean fuel run through the entire system: that is the work, and the way the car was driven counts as much as the mileage. Short trips, like the school run to St Anne's CofE VC Primary School, are one matter. Very different a second time: a run to Worcester, under 15 miles away, or any distance on the M5, under 15 miles from Hales Park, where the motor kept running hard.
Driven till it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer acting like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Hop Pole Lane. Long-term damage is very rare if a car is pulled over quickly, and the fuel drain and flush that still go first deal with it.
What Hales Park motorists get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing comes out when you top up — that tank simply holds more of the same mixture. Percentage isn't how a diesel fuel system tolerates petrol, however much that guidance supposes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. Lubrication matters more on newer diesels, not less, because their fuel runs through smaller components at higher pressure.
This is the one that fools people. Myth: "If it starts and drives, there's no harm done." Any petrol engine fed diesel usually won't run, and so the driver stops and the harm stops with them. Feed petrol to a diesel and it usually fires up, ticks over and drives away like nothing happened — all the while its pump is wearing. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive it home." It's an outdated fix for a separate issue. That petrol is still in your tank afterwards, and what it has thinned is not put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in the filter and lines, waiting to go right back through the pump on the next start. On top of that, petrol cleared into a can by the road is truly hazardous.
Petrol in a diesel: how does it occur?
Carelessness is rarely the cause, and no one means to do it. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol car at all. So the mistake runs one way.
Habit and the vehicle getting out of step is when it happens. Any motor that's new to you — hired, on loan as a courtesy car, or just bought. Two motors on one drive, one petrol, one diesel. A well-known forecourt with the pumps in a different order. Rushing for a train at Kidderminster and fuelling up en route. Years of petrol cars behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. With rain, a call coming in, or children to deal with, the hand simply does what it always has.
Hales Park people: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is usual in the UK — but not on each forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a new motor is the time to check your filler flap — on it, or on the cap, many motors state which fuel to use.
- Label your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" out loud. Silly, perhaps, but it does the trick.
- Mistakes like this are easy to make while your mind is on something else, and so your phone goes away.
- Add-on devices exist for cars without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol in the tank makes a weaker mix. It doesn't change what to do next, which is still not to crank it.
Already put petrol in a diesel in Hales Park?
Then the order of things is brief. Leave it unstarted, with your ignition off as well. If you're still on the forecourt — Texaco or anywhere else — ask the attendants to help you push the car away from the petrol pump. Then ring 0333 366 0103 and tell us what got in, roughly how much, and if it has run.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Hales Park, since AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job in Hales Park costs more than another
Four separate tasks lie behind the four situations above — which is why there's no honest single price. Which of them you are in is mostly what shifts your cost. Next it's the ratio — how much petrol went in against how much that tank takes — and after that where your car is and whether our van can reach it safely.
That is why our technicians ask three questions before quoting instead of after: what was put in, how much, and if it has run. A range becomes a straight figure when the answers are in.
About Hales Park itself
Hales Park is a suburban area in Worcestershire, situated inland at an elevation of around 91 metres. Hales Park lies approximately 13 miles northwest of Worcester and about 111 miles west of London, near other localities such as The Lakes and Hawthorn Bush. Hales Park is characterised by its predominantly detached housing stock, reflecting its development as a residential area. Hales Park remains a part of the wider Worcester urban fringe, with nearby features like Bark Hill.
Fuel drain cover across Worcestershire, Hales Park included
The Lakes, Hawthorn Bush and Bark Hill are among the spots around Hales Park that the same vans work, answering petrol in diesel calls across Hales Park's DY postcode area. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Hales Park: still at the petrol pump?
In that case, you could not be in a better place. Call, and leave it turned off.