Should You Worry? Petrol in a Diesel Car in Waringstown
Probably less than you are now — as long as no one has started the vehicle. Till the ignition primes the pump, your starter cranks, or your vehicle is driven, petrol in a diesel tank simply sits there and does nothing. Which makes the honest reply to that first Waringstown query — "have I wrecked it?" — usually no. Leave the engine off then phone Petrol in Diesel — that is how you keep it that way. 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 never do it again.
Inside the engine: what petrol in a diesel really does
Two jobs fall to diesel on its journey through a motor. Before it burns, it protects — and then it burns. Very fine tolerances go into the injectors and the high-pressure pump, and only your diesel running through stops those surfaces grinding together.
Of those two tasks, petrol manages the first poorly and the second never. The clattering comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication your system rests on, and any pump running on such a blend is wearing itself.
Seen together, they show what shape the trouble takes. It is movement that does the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to the injectors beyond it.
Four scenarios we see in Waringstown: how bad is petrol in a diesel?
Fuelled, and never started: nothing beats it. Just the tank has petrol in it, so the task is emptying your tank and rinsing your system where the car sits. This scenario can only truly happen at a forecourt: anywhere else, your car got there by being driven.
The ignition switched on, or a short start. Petrol has come out of your tank and got to the filter and the lines, since your system has been primed. Drain, flush, deal with your filter: still normally easy.
Driven a few miles. Now your pump has spent those miles running on weakened fuel. Mileage is only half of that; how hard it was driven matters just as much. Either way the work runs to the tank, the lines, the filter and fresh fuel through the whole system. Short trips, such as the school run to the local primary school, are one thing. A run as far as Lisburn, under 15 miles away, is a very different job. So is any distance on the M77, over 50 miles from Waringstown, where the motor has been working hard the whole time.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. What you are hearing is the motor signalling fuel that no longer behaves like diesel. Stop wherever you are — the verge on Heugh Road, a lay-by, a side street — and leave it where it is. Long-term damage is very unusual if a vehicle is stopped soon, and the drain and flush that still come first take care of it.
Waringstown motorists and the petrol in a diesel myths they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A fuller tank of the same mix is all you get, since topping up takes out nothing. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice assumes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. A current diesel sends its fuel through finer components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that fools people. The driver of a petrol engine fed diesel usually stops, because it will not run, and the harm stops with them. Whilst your pump grinds, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Fine and running are not the same thing.
An outdated fix for a separate fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." The petrol is still inside your tank after that, and what it has thinned isn't put back.
The next start sends petrol back round the pump out of your lines and the filter, where some of it sits after your engine has been run. That's why a DIY tank drain does not sort it — a myth. Also, a can of petrol filled by the roadside is truly dangerous.
Petrol in a diesel: how does it happen?
Carelessness is rarely the cause, and no one means to do it. One way only, since of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it easy.
Habit and the vehicle getting out of step is when it occurs. Courtesy car, hire car, or a car that's brand new. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Filling up in a rush en route to the nearest station, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. Add a back seat full of children, a phone call or rain, and habit takes over.
Waringstown people: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust the label on the pump, not the colour.
- In a motor you don't know, look inside the flap over the filler or at the cap before the first fill: plenty of vehicles state the fuel there.
- One of each in the house? Mark your key to your diesel — a coloured fob, a sticker — because intending to remember is not enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it does the trick.
- Mistakes like this are straightforward to make while your mind is on something else, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a safety net, and keep checking the pump.
- Stop the moment you notice. Less petrol inside the tank makes a weaker blend. It doesn't change what to do next, which is still not to crank it.
Waringstown: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with the ignition switched off as well. If you are still on the forecourt — the nearest petrol station or anywhere else — ask the staff to help you roll the vehicle clear of the petrol pump. Then ring 0333 366 0103 and tell us what was put in, about how much, and whether it's run.
If it was AdBlue instead of petrol, say so. That is a separate issue — corrosion and deposits rather than lost lubrication — and it has its own page for Waringstown.
What makes one Waringstown petrol in a diesel job cost more than the next
Four different tasks lie behind the four scenarios above — which is why there's no honest single price. The scenario itself does most of the work of moving your cost. Two things follow that: the petrol that was put in as a proportion of what your tank takes, then the place your car is in and whether a van can get to it safely.
Before any quote, not after, we ask three questions: your fuel that got in, its volume, and if it has run. That is why. Those replies change a range into a straight figure.
About Waringstown itself
Waringstown is a locality in County Down, situated inland at an elevation of 48 metres, approximately 12 miles from Lisburn. Waringstown is characterised by its predominantly detached housing stock, reflecting its residential nature. Waringstown sits near several nearby places, including Gibsons Hill, Donaghcloney, and Bleary, in the wider region of Northern Ireland.
Waringstown and County Down: where our fuel drain cover runs
Waringstown waits in the BT postcode area, and the teams that answer petrol in diesel jobs there work the places around it as well — Gibsons Hill, Donaghcloney and Bleary among them. We drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Waringstown: still at the pump?
No position is better: that is where you are. Turned off it remains; then ring.