Should You Worry? Petrol in a Diesel Car in Blakeney
Probably less than you already are — as long as nobody has started the vehicle. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through the system — the ignition priming your pump, your starter, or the drive itself. So the fair answer to the first question anyone around Blakeney asks, "have I ruined it?", is usually no. Petrol in Diesel is who to phone, with your motor left off, so it stays that way. Further down, this page sets out what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the motor?
Passing through an engine, diesel does two things at once. It burns, and before it combusts it protects. Made to extremely fine gaps, the injectors and the pump rely on the diesel flowing through them to stop their surfaces wearing against one another.
Petrol does the first job badly and the second not at all. The knocking 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 away the protection the fuel system depends on, and any pump working on that mix is wearing itself.
Put these together and the shape of the trouble is plain. It's movement that does the damage, not contact. A tank with petrol in it is a fuel problem. 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 the fuel to your injectors downstream.
Four situations our technicians see around Blakeney: how serious is petrol in a diesel?
The best case there can be: filled up, not once started. At a forecourt, and really only there, that petrol is still confined to your tank — since everywhere else the vehicle was driven to reach it. The task is emptying and purging on the spot.
Your ignition turned on, or a short start. The system has been primed, so petrol has left that tank and got to the fuel filter and the fuel lines. Still generally easy: drain, flush, and your filter dealt with.
Driven a few miles. Now your pump has spent these miles working on diluted fuel. The work is your tank, the fuel lines, the filter and fresh fuel through the entire system, and how hard the vehicle was driven counts as much as how far. On the school run to Blakeney Church of England Voluntary Aided Primary School, the miles is small. Getting as far as Norwich, under 50 miles away, makes a very different job — as does any distance on the A1(M), over 50 miles from Blakeney, with the motor labouring hard the whole time.
Driven on until it complained — knocking, smoke, a lumpy idle, a dead throttle. That's the motor telling you its fuel has stopped behaving like diesel. Stop wherever you are — the verge on Morston Road, a lay-by, a side street — and leave the vehicle where it is. A vehicle stopped quickly very seldom has long-term damage, since the fuel drain and the flush, which still come first, sort it out.
What Blakeney people get told about petrol in a diesel — and the myths in it
False: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a bigger tank of the same mix. That guidance presumes a diesel fuel system handles petrol by percentage. It does not.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that's how a newer diesel handles its fuel, and so the lubrication counts more, not less.
"It starts, it drives, so no harm done" — the myth that catches most motorists than any other. A petrol engine fed diesel generally will not run, and so the driver stops and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump wears. Being able to run is not the same as being fine.
Myth: a two-stroke additive lets you to drive home. It was an old fix, supposed for another problem. That petrol is still in that tank after that, and what it has weakened isn't put back.
Once the engine has been run, part of that petrol is in your filter and the lines, not your tank — and the next start sends it straight back through your pump. So the myth "drain that tank yourself and you're sorted" doesn't hold. Also, a can of petrol drained by the kerbside is truly hazardous.
How petrol ends up: petrol in a diesel
A careless moment is rarely the cause, and no one means to do it. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol car at all. So the mistake runs one way.
Habit and your car falling out of step is when it takes place. A car that is new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Filling up in a hurry on the way to Sheringham, with a train to catch. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is precisely the moment it happens. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up in Blakeney
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- The first fill in a new car is the time to check your filler flap — on it, or on the cap, plenty of cars state which fuel they take.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, for a home with one of each.
- Before the nozzle leaves the pump the first time you fill a hired or new vehicle, say "diesel" aloud. Silly, perhaps, yet it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away then keep your mind on the pump.
- Some diesels have a filler designed to block a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Less petrol means a weaker blend, and so stop as soon as you notice — though remembering that the next stage is unchanged. It's still not to start the vehicle.
Blakeney: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. If you are still on the forecourt — Pace or anywhere else — ask the attendants to help you push the vehicle clear of the pump. What got in, about how much, and if it's run: tell us that when you phone 0333 366 0103.
Say so if it was AdBlue rather than petrol: it is a different problem, with its own page for Blakeney, because AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job in Blakeney costs more than another
The four situations above are four separate tasks, so no single price for this would be honest. Chiefly, the cost moves with which one you are in. Where the vehicle is counts too, and whether our van can safely reach it, after the share of petrol to what that tank takes.
That's why our engineers ask three queries before quoting instead of after: what got in, how much, and whether it has run. A range becomes a straight figure once those replies are in.
About Blakeney and where it is
Blakeney is a small coastal village in north Norfolk, situated on the marshy coast near the Norfolk Coast Area of Outstanding Natural Beauty. Blakeney sits at a low elevation of around 8 metres, close to the villages of Wiveton and Morston. Blakeney has a population of approximately 556 people, living in predominantly detached housing. Blakeney is located near Cley next the Sea, and is about 25 miles from Norwich, the nearest city.
Across Norfolk and in Blakeney: fuel drain cover
Petrol in diesel jobs around Blakeney — part of the NR postcode area — go to vans that also cover the places round it, Wiveton, Morston and Cley next the Sea among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and the vehicle does not need to come to us.
In Blakeney and still at the petrol pump?
Then you are in the best place there is. Phone, and leave it switched off.