Kittybrewster: Petrol in a Diesel Car? How Worried to Be
Not started? Then less anxious than you likely feel. Till the ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank simply rests there and does nothing. Which means the truthful reply to that first Kittybrewster query — "have I ruined it?" — usually no. Keep it that way: leave the engine off and ring Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and the way to make sure you never do it again.
Inside the motor: what petrol in a diesel really does
Two tasks fall to diesel on its route round a motor. It burns, and before it burns it protects. Extremely fine gaps are built into the fuel injectors and the high-pressure pump, and just your diesel running through stops those surfaces grinding together.
Petrol does the first job poorly and the second not at all. It's thinner than diesel and strips away the protection the fuel system depends on, and 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's where the rattling comes from.
Together, those leave the shape of the issue plain. Contact does not do the damage — circulation does. Petrol in a tank is a fuel fault. After your pump has been working on that petrol, a mechanical fault has started: anything shed by a pump that is grinding is carried downstream to the injectors with the fuel.
Four situations our engineers see around Kittybrewster: how bad is petrol in a diesel?
Fuelled but never started — the best it gets. On a forecourt, and really only there, the petrol is still confined to the tank — because anywhere else the car was driven to reach it. The job is emptying and rinsing on the spot.
A brief spell of running, or just the ignition on. The fuel system has been primed, and so petrol has left that tank and reached the filter and your lines. That is normally still a simple job — a drain, a flush, and your filter dealt with.
Those few miles on the road meant your pump labouring on fuel thinned by petrol the whole way. Tank, lines, filter, then clean fuel put through the entire circuit: that's the 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. Driving as far as Aberdeen, under 3 miles away, makes a very different job — as does any miles on the M90, over 50 miles from Kittybrewster, with the engine labouring hard all the way.
Driven on until it protested — knocking, smoke, a lumpy idle, a dead throttle. That is the motor telling you its fuel no longer is acting like diesel. Pull up where you are — on the verge on Clifton Road, at the kerb, down a side road — and do not move it. A vehicle stopped early very seldom has permanent damage, as the fuel drain and the flush, which still go first, take care of it.
Kittybrewster people and that 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." Topping up removes nothing; it gives you a fuller tank of the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
Myth: a modern diesel copes with a bit of petrol. If anything, the opposite. Protection matters more on modern diesels, not less, since their fuel runs through more precise components at higher pressure.
This is the one that catches people. Myth: "If it starts and drives, there's no harm done." Any petrol motor fed diesel usually won't run, so the driver stops and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, whilst the pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive it home." It's an outdated workaround for a distinct fault. It does not put back what petrol has thinned, and that petrol is still inside the tank afterwards.
Once the engine has been run, part of that petrol sits in the filter and your lines, not that tank — and your next start sends it straight back through your pump. So the myth "drain the tank yourself and you are sorted" does not stand up. And, a can of petrol filled by the kerbside is genuinely hazardous.
Why petrol in a diesel occurs so easily
Carelessness is rarely the cause, and nobody means to do it. A diesel nozzle generally won't fit a petrol vehicle, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake simple, and just in one direction.
It takes place when routine and the car stop matching. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the drive of the same household. The pumps in a different order on a familiar forecourt. Racing for a train outside Aberdeen and fuelling up en route. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. Your hand repeats what it has always done when you add rain, a phone call or a back seat full of children.
Preventing petrol in a diesel next time you fill up around Kittybrewster
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the petrol pump's label; the colour is only a hint.
- The first fill in a new motor is the time to check your filler flap — inside it, or on the cap, many motors state the fuel they take.
- One of each in the household? Mark the key to your diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- 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 pump. It seems silly and it works.
- Whilst you are thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop reading the pump.
- As soon as you realise, stop: less petrol in your tank means a weaker mix. What to do next doesn't change, though — still do not crank it.
Kittybrewster: already put petrol in a diesel?
In that case, there is just a short order of things. Never fire it up, and do not turn your ignition on. Ask the staff to help you roll it away from the petrol pump if you're still at the forecourt, whether that is BOC or anywhere else. Call 0333 366 0103 next, with three facts — your fuel, the approximate amount, and if it's run.
Say so if it was AdBlue rather than petrol: it's a different issue, with its own page for Kittybrewster, since AdBlue brings corrosion and deposits rather than lost protection.
One petrol in a diesel job in Kittybrewster costs more than another. Why?
A fair single price does not exist here: four scenarios, four separate jobs. What shifts the cost is chiefly which of them you are in. Two things come after that: the petrol that was put in as a proportion of what that tank takes, then the place the car is in and whether a technician can reach it safely.
Three queries come first, before any quote, instead of after — what went in, how much, has it run — and that is the reason. Those replies change a range into a straight figure.
About Kittybrewster and where it is
Kittybrewster is a coastal suburban area in Aberdeen City, situated approximately 1.2 miles from Aberdeen city centre. Kittybrewster sits at an elevation of 39 metres, with its predominant housing stock consisting of flats. Kittybrewster is located near other suburban areas such as Tillydrone, Old Aberdeen, and Hilton, and is home to a population of around 9049 people.
Fuel drain cover in Kittybrewster and across Aberdeen City
Kittybrewster waits in the AB postcode area, and our teams that answer petrol in diesel jobs there work the spots near it as well — Tillydrone, Old Aberdeen and Hilton among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our technicians drain, and the vehicle doesn't need to come to us.
Kittybrewster: still at the pump?
Then, you could not be in a better place. Keep it off. Ring.