Ardnadam: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, if it hasn't been started. Till your ignition primes your pump, the starter turns, or the vehicle is driven, petrol in a diesel tank simply waits there and does nothing. Which means the truthful reply to that first Ardnadam query — "have I ruined it?" — normally no. Leave your engine off and call Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and the way to make sure you never do it again.
Petrol in a diesel: what does it do to your engine?
Passing through a motor, diesel is doing two jobs at once. It lubricates first, and after that does it burn. Built to very fine gaps, your injectors and the pump depend on the diesel moving through them to keep their surfaces from wearing against one another.
Of those two jobs, petrol manages the first badly and the second never. It's thinner than diesel and takes away the protection the system depends on, so a pump running on a petrol mixture 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 knocking comes from.
The shape of the issue is clear when you put those together. The damage is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds travels on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault begins.
Petrol in a diesel in Ardnadam: how serious is it? Four cases
Fuelled up, not once started. The best case there can be. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol kept in your tank alone, it is drained and flushed on the spot, and nothing more is needed.
Ignition on, or started for a second. With your system primed, your lines and filter already hold petrol that came from your tank. That's generally still an easy task — a drain, a flush, and the fuel filter dealt with.
Those few miles driven meant the pump working on fuel diluted by petrol the whole way. Distance is only half of it; how hard it was driven matters equally. Either way the work runs to your tank, your lines, the filter and clean fuel through the whole circuit. On the school run to the local primary school, the miles is short. Very different again: a trip to Glasgow, under 50 miles away, or any miles on the M8, under 25 miles from Ardnadam, where the motor never stopped running hard.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That is your engine telling you its fuel no longer is acting like diesel. Pull up wherever you are — the verge on Queen's Road, a lay-by, a side street — then leave the car where it is. The drain and flush-through still come first, and they take care of it: if a car is pulled over quickly, long-term damage is very rare.
Myths Ardnadam people hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A bigger tank of the same mixture is all you get, because topping up takes out nothing. That guidance assumes a diesel fuel system handles petrol by percentage. It does not.
Not so: a current diesel copes with a bit of petrol. If anything, the reverse. At higher pressure, through smaller components: that's how a modern diesel moves its fuel, so the lubrication matters for more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there is no harm done." Feed diesel to a petrol motor and it usually will not run, and so the driver stops — and the damage stops with them. Feed petrol to a diesel and it generally fires up, ticks over and drives away as if nothing has happened — all the while its pump wears. Fine and running aren't the same thing.
An old fix for a distinct problem is behind this one. Myth: "Add some two-stroke oil and drive the car home." The petrol is still inside the tank after that, and whatever 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 your filter and lines, ready to go right back through your pump on your next start. On top of that, petrol cleared into a can by the road is genuinely hazardous.
Why petrol in a diesel happens so easily
A careless moment is seldom the cause, and no one means to do it. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol vehicle. That's how the forecourt makes it simple.
When routine and the vehicle stop matching, it takes place. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. One petrol and one diesel on the driveway of the same household. Your ordinary forecourt, its pumps now in a different order. Racing for a train outside Gourock and filling up en route. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. With rain, a call coming in, or a car full of children to deal with, the hand just does what it always has.
Preventing petrol in a diesel next time you fill up around Ardnadam
- The label is what matters, and so check the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on every forecourt.
- Many motors state the fuel type inside the filler flap or on the cap, so check it on your first fill in any motor you do not know.
- Mark your 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 meaning to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It sounds daft and it does the trick.
- Put your phone away. This is an easy mistake to make while you're thinking about something else.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that won't take a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Less petrol makes a thinner mixture, and so stop the moment you realise — though remembering that the next stage is unchanged. It's still not to fire it up.
Ardnadam: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. Ask the attendants to help you push it clear of the petrol pump if you're still at the forecourt, whether that's the nearest petrol station or anywhere else. Call 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate issue — Ardnadam has a page all for it.
What makes one Ardnadam petrol in a diesel job cost more than the next
There's no fair single quote for this, since the four scenarios above are four different tasks. Mostly, the cost moves with which situation you're in. Where the vehicle is matters too, and whether our van can safely get to it, after the share of petrol to what your tank holds.
Ahead of any quote, not after, come three queries: the fuel that got in, its amount, and whether it's run. That's why. Given the replies, there is a straight figure rather than a range.
About Ardnadam and its setting
Ardnadam is a coastal suburban area in Argyll and Bute, situated near the towns of Sandbank and Kilmun. Ardnadam has a population of around 769 people and is characterised by detached housing. Ardnadam sits at a low elevation of 15 metres, close to the shores of the Clyde estuary. Ardnadam is located near Hunters Quay, with Glasgow approximately 28 miles away to the east.
Across Argyll and Bute and around Ardnadam: fuel drain cover
Sandbank, Kilmun and Hunters Quay are among the places near Ardnadam that the same teams work, answering petrol in diesel call-outs across Ardnadam's PA postcode area. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Still at the pump around Ardnadam?
Nothing beats it: that's where you are. Phone, and keep it turned off.