Petrol in a Diesel Car in Dunkirk: How Worried Should You Be?
Provided it hasn't been started, worry less than you likely are. Everyone in Dunkirk begins with "have I ruined it?", and the honest answer is generally no: petrol left in the tank of a diesel remains harmless until priming, cranking or driving draws it into the system. Petrol in Diesel is who to ring, with the engine kept off, so it remains that way. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never do it again.
Petrol in a diesel: what does it do to your engine?
On its way through an engine, diesel does two tasks. Oiling comes before burning; it does both. Very fine clearances are built into the fuel injectors and your high-pressure pump, and just the diesel running through stops their surfaces grinding together.
Petrol does the first job poorly and the second not at all. It is thinner than diesel and takes away the protection the system depends on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the rattling comes from.
The shape of the issue is plain once you put those together. Not contact but circulation is what does the damage. Any tank with petrol in it is a fuel issue. The start of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors beyond it.
Four scenarios our technicians see around Dunkirk: how serious is petrol in a diesel?
The best case there is: filled up, not once started. That petrol is inside your tank and just your tank, and the job is a drain and a flush where the car sits. This is the one scenario that can only really take place on a forecourt, as anywhere else the vehicle has been driven to get there.
Your ignition switched on, or a short start. With the system primed, your lines and filter now contain petrol that has come from your tank. Normally nothing more than clearing, cleaning and seeing to the filter, so still simple.
Those few miles driven meant your pump working on fuel weakened by petrol throughout. Tank, lines, filter, then clean fuel put through the whole circuit: that is the work, and the way your car was driven matters as much as the miles. The school run to Dunkirk Primary and Nursery School is one matter. A run as far as Nottingham, under 3 miles away, is a very different job. So is any mileage on the M1, under 5 miles from Dunkirk, where the motor has been labouring hard the whole time.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. The fuel isn't behaving like diesel any more, and the engine is saying so. Stop wherever you are — the verge on Lace Street, a lay-by, a side street — and leave it where it is. Permanent damage is very rare if a vehicle is stopped early, and the fuel drain and flush that still come first take care of it.
Dunkirk motorists and that petrol in a diesel myths they hear
False: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all you get, since topping up takes out nothing. The idea behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. A current diesel sends its fuel through smaller parts at higher pressure, which makes the protection matter more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. The driver of a petrol motor fed diesel usually has no choice but to stop, because it will not run, and the harm stops with them. Feed petrol to a diesel and it generally fires up, idles and drives away as if nothing happened — all while its pump wears. Fine and running aren't the same at all.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated fix for a separate fault. The petrol is still inside the tank afterwards, and what it has weakened is not put back.
The next start draws petrol back round the pump out of the lines and the filter, where some of it ends up after the motor has been run. That is why a DIY tank drain doesn't sort it — a myth. Besides, petrol emptied into a can by the road is truly risky.
Petrol in a diesel: how does it happen?
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol motor. That's how the forecourt makes it straightforward.
Routine and your car falling out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Racing for a train outside Beeston and filling up en route. A new-to-you diesel Skoda Octavia, its first fuelling, and a motorist used to petrol: exactly when it takes place. Throw in rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
Next time you fill up around Dunkirk: avoiding petrol in a diesel
- The label is what matters, so read the pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- Inspect your filler flap. Many cars state the fuel inside the flap or on the cap. Look at it on your first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a home with one of each.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" out loud. Silly, perhaps, yet it does the trick.
- Put your phone away. This is an easy mistake to make whilst you are thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop checking the pump.
- Noticing it mid-fill? Stop at once. A weaker blend follows from less petrol in that tank, but the next step stays the same: don't fire it up.
Petrol already in a diesel in Dunkirk? Start here
Then the order of things is short. Starting it is out, and so is turning on the ignition. The attendants on the forecourt — whether at the nearest petrol station itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Then ring 0333 366 0103 and tell us what went in, roughly how much, and whether it has run.
Say so if it was AdBlue rather than petrol: it's a separate issue, with its own page for Dunkirk, because AdBlue brings corrosion and deposits rather than lost lubrication.
Dunkirk petrol in a diesel jobs: why one costs more than another
The four scenarios above are four different tasks, so no single price for this would be fair. Mostly, your cost shifts with which situation you're in. Beyond that it is the proportion — how much petrol went in against how much that tank holds — and then where the car is and whether our van can get to it safely.
What got in, how much, and if it's run — three queries our engineers ask before costing, not after, for precisely that reason. A range turns into a straight figure once the answers are in.
About Dunkirk and its setting
Dunkirk is a suburban area in Nottinghamshire, situated near the lakeside and approximately 1.8 miles from Nottingham city centre. Dunkirk has a relatively low elevation of 26 metres and is surrounded by other nearby places such as Old Lenton, New Lenton, and Lenton Abbey. Dunkirk is characterised by its predominant semi-detached housing stock and is home to around 2813 residents.
Fuel drain cover in Dunkirk and across Nottinghamshire
Petrol in diesel calls around Dunkirk — part of the NG postcode area — go to teams that likewise cover the spots around it, Old Lenton, New Lenton and Lenton Abbey included. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations we drain.
In Dunkirk and still at the petrol pump?
In that case, you could not be in a better position. Keep it off. Phone.