Minchinhampton: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, provided it has not been started. Till your ignition primes your pump, your starter cranks, or your car is driven, petrol in a diesel tank simply waits there and does no harm. Which makes the honest reply to that first Minchinhampton query — "have I ruined it?" — normally no. Keep it that way: leave your motor off and call Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and the way to make sure you never do it again.
Inside your engine: what petrol in a diesel does
Diesel has two tasks on its way through a motor. Oiling comes before burning; it does both. What stops the surfaces inside your high-pressure pump and the injectors from grinding against one another is your diesel flowing through them — they're built to extremely fine gaps.
Of those two jobs, petrol handles the first badly and the second never. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the mixture 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.
Seen together, they show what shape the trouble takes. The damage is done by movement, not by contact. Petrol in the tank is a fuel fault. Once your pump has been running on that petrol, a mechanical problem has begun: anything shed by a pump that is wearing travels downstream to the injectors with the fuel.
Four situations our technicians see around Minchinhampton: how bad is petrol in a diesel?
Fuelled but never started — the best it gets. At a forecourt, and truly only there, that petrol is still limited to the tank — because everywhere else the vehicle was driven to reach it. The job is draining and cleaning on the spot.
A brief spell of running, or merely your ignition on. The system has been bled, so petrol has left the tank and reached the fuel filter and the fuel lines. Normally little more than draining, purging and sorting the filter, so still straightforward.
A few miles driven, and your pump has spent each of them running on thinned fuel. How hard your car was driven matters as much as how far, and this work covers that tank, the fuel lines, the filter and fresh fuel through the entire circuit. On the school run to Minchinhampton Primary Academy, the mileage is short. Very different a second time: a run to Gloucester, under 15 miles away, or some distance on the M5, under 10 miles from Minchinhampton, where the engine kept running hard.
Knocking, an uneven idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the motor reporting fuel that no longer runs like diesel. Pull up wherever you are — the verge on Market Square, a lay-by, a side street — then leave the vehicle there. A car pulled over soon very seldom has long-term damage, since the drain and the flush-through, which still go first, sort it out.
Myths Minchinhampton drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up removes nothing; it gives you a bigger tank of the same mixture. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." More precise components and higher pressure are the way a modern diesel runs its fuel, and that makes the protection matter more, not less.
The myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it generally will not run, and so the motorist stops — and the damage stops with them. A diesel fed petrol usually starts, idles and drives away as if nothing has happened, whilst the pump grinds. Fine and running are not the same at all.
Myth: a two-stroke additive lets you to drive home. It is an old fix, supposed for another problem. What petrol has diluted remains weakened, and the petrol remains in that tank anyway.
Once the motor has run, part of that petrol is in the fuel filter and the lines, not the tank — and your next start pulls it right back through your pump. So the myth "drain that tank yourself and you're sorted" does not hold. Draining petrol into a can by the roadside is also truly risky.
Why petrol in a diesel occurs at all
It's rarely carelessness, and nobody does it on purpose. One way only, because of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it simple.
When routine and the car stop matching, it takes place. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill en route to Stroud. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you on 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.
Preventing petrol in a diesel next time you fill up around Minchinhampton
- The label is what matters, and so read the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of cars state the fuel type there.
- A coloured fob or a sticker on the diesel's key achieves 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 fuel a hired or new vehicle, say "diesel" aloud. Daft, perhaps, yet it works.
- Mistakes like this are simple to make whilst your mind is on something else, and so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to reject a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Less petrol means a weaker mixture, and so stop as soon as you realise — while remembering that your next step is unchanged. It's still not to crank it.
Minchinhampton: already put petrol in a diesel?
In that case, there is just a short order of things. Don't turn your ignition on, and don't start it. The attendants at the forecourt — whether at Shell itself or wherever you filled up — will usually help roll it away from the pump if you ask. What got in, roughly how much, and whether it has run: tell us that when you call 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate fault — Minchinhampton has a page just for it.
Minchinhampton petrol in a diesel tasks: why one costs more than another
Four separate tasks lie behind the four situations above — which is why there is no fair single quote. Which of them you're in is mostly what shifts your cost. The share matters next, meaning how much of that tank is petrol, followed by the position of the vehicle and whether getting to it is safe for a technician.
That's why our engineers ask three queries before costing rather than after: what got in, how much, and if it has run. The answers turn a range into a straight figure.
About Minchinhampton
Minchinhampton is a town in Gloucestershire, situated inland at an elevation of 184 metres, with detached housing being the predominant type of accommodation. Minchinhampton lies near the cities of Gloucester and the smaller nearby places of Bubblewell, Forwood, and Knave-in-hole. Minchinhampton is approximately 89 miles west of London, making it a relatively rural town in the South West region. Minchinhampton has a population of around 4522 residents.
Across Gloucestershire and around Minchinhampton: fuel drain cover
Minchinhampton sits in the GL postcode area, and the vans that answer petrol in diesel jobs there work the places around it as well — Bubblewell, Forwood and Knave-in-hole among them. The car doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Minchinhampton: still at the petrol pump?
Then, you couldn't be in a better place. Switched off it remains; then call.