Petrol in a Diesel Car in Newstead: How Worried Should You Be?
Not started? Then less worried than you likely are. Till the ignition primes the pump, your starter cranks, or your car is driven, petrol in a diesel tank simply rests there and does no harm. Which makes the honest reply to that first Newstead query — "have I ruined it?" — normally no. Keep it like that: leave your engine off then phone Petrol in Diesel. Further down, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Diesel has two jobs on its way through a motor. Before it combusts, it protects — and then it combusts. Designed to very fine tolerances, your injectors and the pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
The second job petrol doesn't do at all, and the first it does badly. A pump working on a petrol mix is wearing itself out, since petrol is runnier than diesel and takes away the protection the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the clattering comes.
Together, those make the shape of the issue clear. It's circulation that does the harm, not contact. Any tank with petrol in it is a fuel problem. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with your fuel to your injectors further on.
Four situations we see in Newstead: how serious is petrol in a diesel?
Filled up, not once started. The best case there can be. At a forecourt, and genuinely only there, the petrol is still limited to that tank — because everywhere else the vehicle was driven to reach it. The job is draining and purging on the spot.
Ignition on, or started for a second. Petrol has left your tank and reached the fuel filter and your lines, since the system has been bled. Normally nothing more than emptying, cleaning and sorting the fuel filter, so still simple.
The pump has worked a couple of miles on weakened fuel — that is what driving the vehicle meant. How hard the vehicle was driven matters as much as how far, and the work takes in your tank, the lines, the filter and clean fuel through the entire system. Driving the kids to Newstead Primary and Nursery School is one sort of trip. Driving as far as Nottingham, under 10 miles away, makes a very different job — as does any distance on the M1, under 3 miles from Newstead, with your engine running hard all the way.
Driven till it complained. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and your engine is telling you. Stop wherever you are — the verge on Fraser Street, a lay-by, a side street — then leave the vehicle there. The drain and flush-through still go first, and they deal with it: when a car is pulled over soon, long-term damage is very uncommon.
What Newstead motorists get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. That advice supposes a diesel fuel system tolerates petrol by percentage. It does not.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." A modern diesel runs its fuel through finer parts at higher pressure, which makes the lubrication count more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally leaves a motor that won't run: the motorist stops, and so does the harm. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, while your pump wears. Fine and running aren't the same at all.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a distinct problem. It does not put back what petrol has weakened, and the petrol is still in the tank after that.
If your engine has been run, part of that petrol is in the filter and the fuel lines, not the tank — and the next start sends it right back through your pump. So the myth "drain the tank yourself and you are sorted" does not hold. Draining petrol into a can at the kerbside is also really hazardous.
How does petrol in a diesel take place?
Carelessness is seldom the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol vehicle at all. So the error runs one way.
When habit and the vehicle stop matching, it occurs. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the drive of the same household. Your normal forecourt, its pumps suddenly in a different order. Racing for a train outside the nearest station and filling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. Throw in rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up around Newstead: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what matters.
- Many vehicles state the fuel inside your filler flap or on the cap, and so check there on the first fill in any car you don't know.
- One of each in the household? Label the key to your diesel — a coloured fob, a sticker — since meaning to remember isn't enough.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It works.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for the rest. Treat it as a safety net, then keep checking the pump.
- Stop as soon as you realise. Less petrol in your tank makes a weaker blend. It doesn't change what to do next, which is still not to start the car.
Petrol already in a diesel around Newstead? Start here
Short and simple, then, is the order of things. Leave it unstarted, with your ignition switched off as well. The attendants on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it away from the petrol pump if you ask. What got in, about how much, and whether it's run: tell us those when you call 0333 366 0103.
If it was AdBlue instead of petrol, say so. That's a separate issue — corrosion and deposits and not lost lubrication — and it has its own page for Newstead.
Newstead petrol in a diesel tasks: why one costs more than another
The four scenarios above are four different jobs, so no single price for this would be fair. Mostly, the cost shifts with which situation you are in. Two things come after that: the petrol that was put in as a share of what your tank holds, then the spot the vehicle is in and whether a technician can get to it safely.
That is why our technicians ask three questions before pricing instead of after: what got in, how much, and whether it's run. With those answers, there is a straight figure rather than a range.
About Newstead, briefly
Newstead is a village in Nottinghamshire, situated approximately 8.5 miles north of Nottingham, and is characterized by its terraced housing. Newstead sits inland, at an elevation of around 138 metres, and is located near the villages of Annesley and Annesley Woodhouse. Newstead is a relatively small community, with a population of around 1226 residents, and is part of the wider Nottingham urban area. Newstead is also close to Nuncargate, a nearby settlement in the same region.
Fuel drain cover across Nottinghamshire, Newstead included
Petrol in diesel call-outs around Newstead — part of the NG postcode area — go to vans that also cover the spots round it, Annesley, Annesley Woodhouse and Nuncargate among them. No need to bring the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Still at the petrol pump in Newstead?
Then, you could not be in a better spot. Ring, and keep it turned off.