Should You Worry? Petrol in a Diesel Car in Derrymacash
Provided it has not been started, worry far less than you probably are. Till the ignition primes your pump, the starter cranks, or your car is driven, petrol in a diesel tank simply sits there and does nothing. Which means the truthful reply to the first Derrymacash query — "have I ruined it?" — normally no. To keep it like that, ring Petrol in Diesel and leave the engine alone. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening a second time: that is the remainder of this page.
Your engine and petrol in a diesel: what happens
Two jobs fall to diesel on its route through a motor. Before it ignites, it protects — then it burns. Extremely fine gaps go into the fuel injectors and the high-pressure fuel pump, and just your diesel flowing through stops their surfaces grinding together.
Poorly at the first, not at all at the second: that's petrol. It is runnier than diesel and removes the protection the fuel 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's where the knocking comes from.
Seen together, they make clear what shape the trouble takes. Contact does not do the harm — circulation does. Where that petrol is only inside the tank, it is a problem of fuel, nothing more. The beginning 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 your injectors beyond it.
Four scenarios our technicians see around Derrymacash: how bad is petrol in a diesel?
Filled up, and never started: no case is better. On a forecourt, and truly only there, that petrol is still limited to your tank — since anywhere else the vehicle was driven to reach it. The job is draining and cleaning on the spot.
Your ignition turned on, or a short start. Once primed, your system has drawn petrol from your tank as far as your filter and the fuel lines. Still usually easy: drain, flush, and the filter seen to.
Those few miles on the road were the pump working on fuel thinned by petrol throughout. Tank, lines, filter, then fresh fuel put through the entire system: that's this work, and the way the car was driven matters as much as the miles. Short trips, like the school run to the local primary school, are one matter. A run as far as Armagh, under 15 miles away, is a very different task. So is any distance on the M77, over 50 miles from Derrymacash, where the engine has been labouring hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The motor is telling you the fuel is no longer behaving like diesel. Whether it's the verge on Heugh Road, a lay-by or a side road, stop there and leave it. A vehicle pulled over quickly very rarely has long-term damage, as the fuel drain and the flush-through, which still come first, deal with it.
Myths Derrymacash people 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. A bigger tank of the same mixture is all you get, since topping up takes out nothing. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." Lubrication counts more on newer diesels, not less, because their fuel passes through smaller components at higher pressure.
This is the one that catches people. Myth: "If it starts and drives, there is no damage done." Any petrol engine fed diesel normally won't run, and so the motorist stops and the damage stops with them. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, while the pump wears. Being able to run isn't proof of being fine.
An old workaround for a different issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has diluted remains diluted, and the petrol remains inside that tank regardless.
Once the motor has been run, part of the petrol is in your filter and your lines, not your tank — and your next start pulls it straight back through the pump. So the myth "drain that tank yourself and you are sorted" does not hold. And, a can of petrol drained at the kerbside is truly dangerous.
How does petrol in a diesel occur?
A careless moment is seldom the cause, and no one means to do it. A diesel nozzle mostly will not fit a petrol vehicle, but the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error easy, and only in one direction.
It takes place when habit and the car stop matching. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. Filling up in a hurry on the way to the nearest station, with a train to catch. Precisely the moment it occurs: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. Throw in a back seat full of children, a phone call or rain, and habit takes over.
Next time you fill up around Derrymacash: preventing petrol in a diesel
- Read the 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.
- Check the filler flap. Many motors state the fuel inside the flap or on the cap. Look at it on your first fill in any motor you do not know.
- Label the key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It seems daft and it works.
- Tuck your phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices are available for cars without one, and some diesels come with a filler that will not take a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Spotting it halfway? Stop there and then. A weaker mix follows from less petrol inside that tank, but your next stage remains the same: do not start the vehicle.
Petrol already in a diesel around Derrymacash? Start here
Short and simple, then, is the order of things. Do not turn your ignition on, and don't fire it up. The staff at the forecourt — whether at the nearest petrol station itself or wherever you filled up — will usually help push it clear of the petrol pump if you ask. What was put in, roughly how much, and whether it's run: tell us that when you phone 0333 366 0103.
Corrosion and deposits form the issue with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Derrymacash page.
One petrol in a diesel task around Derrymacash costs more than another. Why?
An honest single quote doesn't exist here: four situations, four separate tasks. Mostly, your cost moves with which situation you're in. Two things come after that: the petrol that went in as a proportion of what your tank takes, then the spot the car is in and whether a technician can reach it safely.
What got in, how much, and if it has run — three queries our technicians ask before pricing, not after, for exactly that reason. Their replies are what turn a range into one firm number.
About Derrymacash and where it is
Derrymacash is a small locality in County Armagh, situated inland at an elevation of 23 metres, approximately 13.5 miles from the city of Armagh. Derrymacash is characterised by its predominantly detached housing stock and is located near other settlements such as Aghacommon and Derrytrasna. Derrymacash has a population of around 794 people and is part of the wider Craigavon area.
Fuel drain cover in Derrymacash and across County Armagh
Derrymacash sits in the BT postcode area, and our vans that answer petrol in diesel jobs there work the places near it as well — Aghacommon, Craigavon and Derrytrasna among them. The vehicle doesn't need to come to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump around Derrymacash, still?
No position is better: that is where you are. Ring, and leave it turned off.