Ainsworth: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry less than you probably are. Till your ignition primes your pump, your starter turns, or your vehicle is driven, petrol in a diesel tank just sits there and does nothing. Which means the honest reply to that first Ainsworth query — "have I ruined it?" — usually no. Leave your motor off then call Petrol in Diesel — that is how you keep it that way. The rest of this page covers 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.
Inside the engine: what petrol in a diesel really does
Two tasks fall to diesel on its journey through a motor. Lubricating comes before burning; it does both. Designed to very fine clearances, the injectors and your pump rely on the diesel flowing through them to keep their surfaces from wearing against one another.
Of these two tasks, petrol manages the first badly and the second never. It's runnier than diesel and removes the protection the system depends on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the clattering comes from.
Seen together, they show what shape the problem has. Not contact but movement is what causes the harm. Where the petrol is only in the tank, it is an issue of fuel, nothing more. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors beyond it.
Ainsworth, petrol in a diesel: four situations, from mild to serious
Filled but not once started — as good as it gets. On a forecourt, and truly only there, that petrol is still limited to your tank — since everywhere else your car was driven to reach it. The job is draining and purging on the spot.
The ignition turned on, or a brief start. Your system has been primed, and so petrol has left the tank and got to the fuel filter and the lines. Still normally simple: drain, flush, and the filter dealt with.
Driven a couple of miles. Now your pump has spent those miles running on thinned fuel. How hard your car was driven counts as much as how far, and this work covers that tank, the fuel lines, the fuel filter and fresh fuel through the whole circuit. On the school run to Christ Church Ainsworth Church of England Primary School, the mileage is small. Very different once more: a trip to Salford, under 10 miles away, or some distance on the Kearsley Spur, under 5 miles from Ainsworth, where the engine kept running hard.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone lumpy. The fuel is not behaving like diesel any more, and your engine is telling you. Whether it is the verge on Bradley Fold Road, a lay-by or a side road, stop where you are then leave it. Permanent damage is very uncommon if a vehicle is stopped soon, and the drain and flush that still go first sort it out.
Stories Ainsworth people hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A fuller tank of the same mix is all it gives, because topping up removes nothing. That guidance assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through more precise components: that is how a current diesel handles its fuel, and so the lubrication matters for more, not less.
"It starts, it drives, so no harm done" — the myth that catches most people than any other. Feed diesel to a petrol motor and it generally will not run, so the driver 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. A running engine doesn't mean fine.
Not so: a two-stroke additive makes it safe to drive home. It was an old fix, meant for another issue. None of what petrol weakened is put back by it — and afterwards, the tank still holds the petrol.
If the engine has been run, part of the petrol sits in your filter and the lines, not that tank — and the next start pulls it right back through the pump. So the myth "drain your tank yourself and you're sorted" does not hold. Besides, petrol drained into a can by the road is genuinely risky.
Why petrol in a diesel occurs so easily
It's seldom carelessness, and no one does it on purpose. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it simple.
When habit and your car stop matching, it occurs. A vehicle that is new to you — hired, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps laid out differently. Filling up in a rush en route to Hall i' th' Wood, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. With rain, a call arriving, or a car full of children to deal with, your hand simply does what it always has.
Preventing petrol in a diesel next time you fill up in Ainsworth
- Check the petrol 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.
- Inspect the filler flap. Many cars state the fuel inside the flap or on the cap. Look at it on the first fill in a car you don't know.
- One of each in the house? Mark your key to your diesel — a bright fob, a sticker — since intending to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It sounds silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Stop as soon as you notice. Less petrol in your tank makes a thinner mixture. It does not change what to do next, which is still not to crank it.
Petrol already in a diesel in Ainsworth? Begin here
Then, there's just a short order of things. Leave it unstarted, with the ignition switched off as well. Ask the staff to help you push it away from the petrol pump if you're still at the forecourt, whether that is Shell or anywhere else. What was put in, roughly how much, and whether it has run: tell us those when you ring 0333 366 0103.
Say so if it was AdBlue rather than petrol: it is a separate problem, with its own page for Ainsworth, because AdBlue brings corrosion and deposits instead of lost protection.
Ainsworth petrol in a diesel jobs: why one costs more than another
An honest single quote does not exist here: four situations, four separate jobs. The scenario itself does most of the work of moving your cost. Two things follow that: the petrol that went in as a proportion of what your tank holds, then the spot your car is in and whether a van can get to it safely.
That's why our technicians ask three questions before quoting instead of after: what went in, how much, and whether it's run. Given the replies, you get a straight figure instead of a range.
About Ainsworth
Ainsworth is a village in Greater Manchester, situated inland at an elevation of 168 metres, approximately 7.9 miles from Salford. Ainsworth has a population of around 1595 people, with semi-detached housing being the predominant type. Ainsworth is located near other local places such as Bottom o the Moor, Cockey Moor, and Starling. Ainsworth is about 171.6 miles from London, making it a relatively distant suburb of the North West region.
Across Greater Manchester and around Ainsworth: fuel drain cover
Bottom o the Moor, Cockey Moor and Starling are among the locations near Ainsworth that the same vans work, answering petrol in diesel call-outs across Ainsworth's BL postcode area. No need to bring the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
At the pump around Ainsworth, still?
Then you are in the best position there is. Leave the vehicle switched off, and ring.