Petrol in a Diesel Car in Birkhill: How Worried Should You Be?
Unstarted? Then less anxious than you likely feel. Everyone around Birkhill starts with "have I wrecked it?", and the fair answer is usually no: petrol left inside the tank of a diesel stays harmless until priming, cranking or driving draws it into your fuel system. Keep it that way: leave your engine off and call Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and the way to make sure you don't do it again.
The engine and petrol in a diesel: what goes on
Diesel has two jobs on its way through a motor. Before it combusts, it lubricates — then it ignites. What keeps the surfaces inside the high-pressure pump and the fuel injectors from grinding against each other is the diesel passing through them — they're built to extremely fine gaps.
Petrol does the first task badly and the second not at all. It's thinner than diesel and removes the protection the system hinges on, so a pump running on a petrol blend 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's where the clattering comes from.
The shape of the problem is clear once you put those together. The harm is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel issue. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with your fuel to your injectors beyond it.
Birkhill, petrol in a diesel: four situations, from mild to major
Fuelled but not once started — as good as it gets. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol kept in the tank alone, it is cleared and flushed on the spot, and nothing more is needed.
Started for a moment, or just the ignition on. Petrol has left that tank and got to your filter and the lines, because your system has been primed. That is normally still an easy job — a drain, a flush, and the fuel filter dealt with.
Driven a few miles. Now the pump has spent those miles running on diluted fuel. Tank, lines, filter, then fresh fuel run through the whole circuit: that is this work, and the way your car was driven counts as much as the mileage. On the school run to the local primary school, the distance is short. Very different a second time: a trip to Dundee, under 5 miles away, or any distance on the M90, under 25 miles from Birkhill, where the engine kept labouring hard.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The fuel is not behaving like diesel any more, and your motor is saying so. Pull up wherever you are — the verge on Sidlaw Terrace, a lay-by, a side street — then leave the vehicle there. Permanent damage is very unusual if a vehicle is pulled over soon, and the fuel drain and flush-through that still go first deal with it.
Petrol in a diesel stories Birkhill drivers hear
False: 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 mixture. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice supposes.
"Modern diesels can handle a little petrol" — a myth, and closer to the opposite. At higher pressure, through smaller parts: that's how a modern diesel moves its fuel, and so the protection counts for more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. A petrol motor fed diesel normally will not run, so the motorist stops and the harm stops with them. Feed petrol to a diesel and it usually starts, idles and drives away as if nothing happened — all while its pump wears. Running doesn't mean fine.
An outdated fix for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive it home." What petrol has weakened stays diluted, and the petrol remains in your tank anyway.
Once the engine has been run, part of that petrol is in your filter and the fuel lines, not your tank — and your next start sends it straight back through the pump. So the myth "drain your tank yourself and you are sorted" doesn't hold. Clearing petrol into a can at the kerbside is also really dangerous.
How petrol ends up: petrol in a diesel
Carelessness is seldom the cause, and nobody means to do it. A diesel nozzle mostly won't go into a petrol vehicle, but the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake straightforward, and just in that direction.
The moment habit stops matching the vehicle is the moment it occurs. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. A hurried fill on the way to Invergowrie with a train to catch. The first fill-up in a diesel Renault Clio after years of driving petrol is exactly the moment it happens. The hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
How to avoid petrol in a diesel on your next fill-up around Birkhill
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what counts.
- Plenty of motors state the fuel type inside your filler flap or on the cap, and so check there on the first fill in any motor you do not know.
- One of each in the house? Label your key to your diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It sounds daft and it does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to block a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a backstop, then keep checking the petrol pump.
- The moment you realise, stop: less petrol in that tank makes a weaker mix. What to do next doesn't change, though — still do not start the car.
Already put petrol in a diesel in Birkhill?
Then the order of things is brief. Leave it unstarted, with your ignition switched off as well. Ask the attendants to help you roll it clear of the pump if you're still at the forecourt, whether that's Asda Express or anywhere else. Phone 0333 366 0103 next, with three facts — your fuel, the approximate amount, and whether it has run.
Corrosion and deposits form the problem with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Birkhill page.
Why one petrol in a diesel task in Birkhill costs more than another
There's no honest single price for this, because the four situations above are four different tasks. The scenario itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a share of what that tank takes, then the spot the car is in and whether a technician can get to it safely.
Three questions come first, before any quote, instead of after — what got in, how much, has it run — and this is the reason. A range becomes a straight figure once the replies are in.
About Birkhill itself
Birkhill is a coastal village in Angus, situated near the city of Dundee and overlooking the Tay Estuary. Birkhill sits at an elevation of 152 metres, with its detached housing stock reflecting its relatively affluent character. Birkhill is close to nearby places such as Muirhead and Backmuir of Liff, and is within easy reach of Dundee's amenities.
Across Angus and around Birkhill: fuel drain cover
Muirhead, Backmuir of Liff and Dronley are among the places around Birkhill that the same teams work, answering petrol in diesel jobs across Birkhill's DD postcode area. The car does not need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Birkhill and still at the petrol pump?
The best position there is, then — that is where you are. Switched off it remains; then phone.