Petrol in a Diesel Car in Plains: How Worried Should You Be?
Far less than you likely are, if it hasn't been started. Till the ignition primes the pump, the starter cranks, or your car is driven, petrol in a diesel tank simply sits there and does no harm. Which makes the honest reply to the first Plains query — "have I ruined it?" — usually no. Leave your motor off then ring Petrol in Diesel — that keeps it like that. The remainder of this page explains what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
The engine and petrol in a diesel: what happens
Diesel has two tasks on its way through a motor. Before it ignites, it protects — and then it combusts. What keeps the surfaces inside your high-pressure pump and your injectors from wearing against one another is your diesel flowing through them — they're built to extremely fine gaps.
Petrol handles the first job badly and the second not at all. It is thinner than diesel and strips away the lubrication the fuel system rests on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the rattling comes from.
Put those together and the shape of the problem is plain. Contact doesn't do the damage — circulation does. Petrol in the tank is a fuel fault. The beginning of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors downstream.
Plains, petrol in a diesel: four situations, from mild to serious
Fuelled up, never started. The best case there is. The petrol is inside that tank and just the tank, and the job is a drain and a flush where the car stands. This is the one scenario that can only truly occur on a forecourt, since anywhere else the car has been driven to get there.
Your ignition turned on, or a short start. Your system has been bled, and so petrol has left the tank and got to your filter and the lines. Still normally straightforward: drain, flush, and your filter sorted.
Driven a couple of miles. Now your pump has spent these miles labouring on diluted fuel. The work is that tank, your lines, your filter and fresh fuel through the entire system, and how hard the car was driven matters as much as how far. Short trips, such as the school run to the local primary school, are one matter. Very different a second time: a run to Glasgow, under 15 miles away, or any miles on the M8, under 3 miles from Plains, where the engine never stopped working hard.
Driven till it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is the engine signalling fuel that no longer acts like diesel. Pull up wherever you are — the verge on Station Road, a lay-by, a side street — and leave the vehicle where it is. A vehicle stopped soon very rarely has lasting damage, as the fuel drain and the flush, which still go first, sort it out.
What Plains drivers get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. Percentage is not how a diesel fuel system tolerates petrol, however much that advice presumes.
Myth: a modern diesel copes with a bit of petrol. If anything, the reverse. A current diesel sends its fuel through more precise parts at higher pressure, which makes the protection matter more, not less.
"It starts, it drives, so no harm done" — the myth that catches most drivers than any other. Diesel in a petrol motor generally means a motor that will not run: the driver stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump wears. Fine and running are not the same thing.
Not so: a two-stroke additive lets you to drive home. It was an old fix, meant for another fault. What petrol has weakened remains thinned, and that petrol remains inside the tank anyway.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in your filter and lines, waiting to go straight back through your pump on your next start. Besides, petrol emptied into a can by the road is truly dangerous.
Why petrol in a diesel happens at all
Carelessness is rarely the cause, and no one means to do it. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it simple, and the slip runs one way.
The moment habit stops matching your car is the moment it takes place. A car that's new to you — hired, on loan as a courtesy car, or just bought. Two vehicles on one driveway, one petrol, one diesel. Your normal forecourt, its pumps now in a different order. Rushing for a train at Drumgelloch and fuelling up en route. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up in Plains
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Check the pump's label; the colour is just a clue.
- In a car you do not know, look inside the flap over the filler or at the cap before the first fill: plenty of cars state the fuel there.
- Label 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.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" aloud. Daft, perhaps, yet it works.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop checking the pump.
- Spotting it mid-fill? Stop at once. A thinner blend results from less petrol inside the tank, but your next step stays the same: don't crank it.
Already put petrol in a diesel around Plains?
Then, there is only a short order of things. Do not switch the ignition on, and don't start it. Yet on the forecourt, at BP or anywhere else? Ask the staff to help you push the vehicle clear of the pump. Next, 0333 366 0103. We'll ask what was put in, roughly how much, and if it has been run.
If it was AdBlue and not petrol, say so. That's a different problem — corrosion and deposits and not lost lubrication — and it has its own page for Plains.
Plains petrol in a diesel jobs: why one costs more than another
There's no fair single quote for this, since the four scenarios above are four different jobs. What moves your cost is mostly which of them you're in. The share matters next, meaning how much of that tank is petrol, followed by the location of your car and whether getting to it is safe for a van.
That's why our technicians ask three questions before costing instead of after: what got in, how much, and if it's run. Those replies change a range into a straight figure.
About Plains and where it is
Plains is a village in North Lanarkshire, situated on the riverside at an elevation of around 170 metres. Plains lies approximately 12 miles east of Glasgow and is part of the wider Glasgow urban area. Plains has a mix of housing types, but predominantly features flat dwellings, and is close to nearby places such as Airdriehill and Clarkston.
Across North Lanarkshire and in Plains: fuel drain cover
Plains waits in the ML postcode area, and our teams that answer petrol in diesel calls there work the places around it as well — Airdriehill, Dunrobin and Clarkston among them. We drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Plains: still at the petrol pump?
The best position there is, then — that's where you are. Ring, and leave it turned off.