Should You Worry? Petrol in a Diesel Car in Northop
Less than you likely are, provided it hasn't been started. Everyone around Northop starts with "have I ruined it?", and the fair answer is usually no: petrol resting in that tank of a diesel stays harmless till priming, cranking or driving pulls it into the fuel system. To keep the vehicle like that, phone Petrol in Diesel and leave your engine alone. The remainder of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
Your engine and petrol in a diesel: what goes on
Two tasks fall to diesel on its journey through a motor. Before it combusts, it lubricates — then it burns. The high-pressure pump and your injectors are designed to very fine tolerances, and your diesel passing through them is what stops those surfaces from grinding against one another.
Petrol does the first job badly and the second not at all. The clattering comes from petrol being designed 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 protection the system depends on, and any pump running on such a mixture is wearing itself.
Put those together and the shape of the trouble is clear. Contact doesn't do the harm — movement does. All a tank with petrol in it amounts to is a fuel problem. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Northop, petrol in a diesel: four cases, from mild to significant
The best case there can be: filled up, never started. On a forecourt, and truly only there, that petrol is still limited to your tank — because everywhere else the car was driven to reach it. The job is draining and rinsing on the spot.
A brief spell of running, or merely your ignition on. The system has been primed, so petrol has left the tank and got to your filter and your lines. Usually nothing more than emptying, purging and seeing to the fuel filter, so still simple.
Those few miles driven were your pump labouring on fuel thinned by petrol the whole way. How hard the vehicle was driven counts as much as how far, and the work takes in the tank, your lines, your filter and clean fuel through the entire system. Short trips, such as the school run to the local primary school, are one matter. Very different a second time: a run to Chester, under 15 miles away, or some mileage on the M56, under 10 miles from Northop, where the motor never stopped labouring hard.
Driven until it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is the motor signalling fuel that no longer runs like diesel. Pull up on the spot — on the verge on High Street, at the kerb, down a side road — and do not move it. The fuel drain and flush still go first, and they deal with it: if a car is pulled over quickly, permanent damage is very uncommon.
Petrol in a diesel stories Northop drivers hear
Myth: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mix is all you get, since topping up removes nothing. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance supposes.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." The motorist of a petrol engine fed diesel usually stops, since it will not run, and the damage stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. Running isn't the same as fine.
An outdated workaround for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol thinned is put back by it — and afterwards, your tank still holds the petrol.
Myth: "Drain the tank yourself and you're sorted." Once the engine has been run, some of the petrol is no longer in that tank: it's in your filter and the lines, and it goes right back through the pump at your next start. It is also truly dangerous to drain petrol into a can at the kerbside.
Why petrol in a diesel takes place at all
Carelessness is rarely the cause, and nobody means to do it. One way only, since of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol motor. That's how the forecourt makes it easy.
Routine and the vehicle getting out of step is how it occurs. Courtesy car, hire car, or a vehicle that is new. Two cars on one drive, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. A rushed fill en route to Flint with a train to catch. Precisely the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Your hand repeats what it has always done when you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel at your next fill-up in Northop
- 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.
- Check the filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in any car you do not know.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key if a household has one of each. So mark it.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems silly and it does the trick.
- Mistakes like this are easy to make whilst your mind is on something else, and so your phone goes away.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- The moment you realise, stop: less petrol inside that tank means a weaker mix. What to do next doesn't change, though — still do not crank it.
Put petrol in a diesel around Northop already?
In that case, there is just a short order of things. Leave it unstarted, with the ignition switched off too. The staff on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it clear of the pump if you ask. Phone 0333 366 0103 next, with three answers — your fuel, the rough volume, and whether it has run.
Say so if it was AdBlue rather than petrol: it's a separate issue, with its own page for Northop, because AdBlue brings corrosion and deposits instead of lost protection.
Northop petrol in a diesel jobs: why one costs more than another
There's no honest single price for this, since the four scenarios above are four different tasks. The situation itself does most of the work of moving your cost. After that it's the share — how much petrol got in against how much your tank takes — and after that where the car is and whether a technician can get to it safely.
Three questions come first, before any quote, instead of after — what went in, how much, has it run — and this is the reason. Those answers turn a range into a straight figure.
About Northop
Northop is a small village in Flintshire, situated near the coast and approximately 10 miles from Chester. Northop sits at an elevation of 101 metres, overlooking the surrounding countryside and nearby Flint Mountain. Northop has a population of around 1030 people, predominantly living in detached houses.
Fuel drain cover in Northop and across Flintshire
Flint Mountain, Soughton and Cefn-eurgain are among the spots around Northop that the same teams work, answering petrol in diesel jobs across Northop's CH postcode area. The vehicle does not 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.
In Northop and still at the pump?
Then you're in the best position there is. Keep it off. Phone.