Calcott: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, if it has not been started. Petrol sitting in a diesel tank does nothing to the motor till something pulls it through the system — the ignition priming your pump, the starter, or driving on its own. So the truthful answer to the first question anyone around Calcott asks, "have I ruined it?", is usually no. Leave the engine off then phone Petrol in Diesel — that is how you keep it that way. Read on 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 don't do it again.
What petrol in a diesel does to the engine
Passing through an engine, diesel is doing two jobs at once. Oiling comes before burning; it does both. Very fine tolerances go into the fuel injectors and the high-pressure fuel pump, and just the diesel flowing through keeps their surfaces from grinding together.
Of those two jobs, petrol handles the first poorly and the second not at all. The knocking comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection your system depends on, and any pump working on that mixture is wearing itself.
Seen together, they show the shape the problem takes. Contact does not do the harm — movement does. All a tank with petrol in it amounts to is a fuel problem. After your pump has been running on that petrol, a mechanical problem has started: anything shed by a pump that's grinding travels downstream to your injectors with your fuel.
How serious is petrol in a diesel? Four situations we see around Calcott
Filled up, never started. The best case there is. Only your tank has petrol in it, so the task is clearing the tank and cleaning the system where the vehicle stands. This scenario can only really happen on a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a second. The system has been primed, so petrol has left that tank and reached the filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually simple.
A couple of miles driven, and your pump has spent each of them running on diluted fuel. The work is your tank, the fuel lines, the filter and clean fuel through the whole circuit, and how hard your car was driven counts as much as how far. On the school run to Bicton Church of England Primary School and Nursery, the distance is small. Any mileage on the M54, under 15 miles from Calcott, means the engine has worked hard throughout, and a run to Wrexham, under 25 miles away, is a very different task too.
Clattering, a ragged idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is your engine reporting fuel that no longer behaves like diesel. Stop wherever you are — the verge on Calcott Lane, a lay-by, a side street — then leave the car there. Permanent damage is very unusual if a vehicle is pulled over soon, and the drain and flush that still come first sort it out.
Petrol in a diesel stories Calcott drivers hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A fuller tank of the same mixture is all you get, because topping up takes out nothing. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through finer components: that's how a newer diesel handles its fuel, so the protection matters for more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools motorists. Feed diesel to a petrol motor and it normally will not run, so the motorist stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile the pump wears. Running isn't the same as fine.
An outdated workaround for a distinct fault is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." That petrol is still in your tank afterwards, and whatever it has weakened is not put back.
Myth: "Drain that tank yourself and you are sorted." Once the motor has run, some of the petrol is no longer inside your tank: it's in your filter and your lines, and it goes straight back through your pump at your next start. Draining petrol into a can by the roadside is also truly hazardous.
How does petrol in a diesel occur?
A careless moment is seldom the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol motor at all. So the slip runs one way.
When habit and your car stop matching, it takes place. Courtesy car, hire car, or a car that is brand new. Two vehicles on one drive, one petrol, one diesel. Your ordinary forecourt, its pumps suddenly in a different order. A train to catch, and a rushed fill on the way to Shrewsbury. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel at your next fill-up in Calcott
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what matters.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of vehicles state the fuel type there.
- One of each in the home? Label your key to your diesel — a bright fob, a sticker — because meaning to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds daft. It works.
- Mistakes like this are easy to make whilst your mind is on something else, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and aftermarket devices are available for the remainder. Count it as a backstop, and keep checking the petrol pump.
- Noticing it mid-fill? Stop at once. A weaker mix results from less petrol inside your tank, but your next stage remains the same: don't crank it.
Put petrol in a diesel in Calcott already?
Then, there is just a short order of things. Starting it is out, and so is switching on your ignition. Still on the forecourt, at Four Crosses Filling Station or anywhere else? Ask the staff to help you roll the vehicle clear of the pump. Ring 0333 366 0103 next, with three facts — the fuel, the approximate amount, and if it's run.
If it was AdBlue instead of petrol, say so. That is a separate problem — corrosion and deposits rather than lost lubrication — and it has its own page for Calcott.
Calcott petrol in a diesel jobs: why one costs more than another
The four scenarios above are four different jobs, so no single price for this would be honest. What shifts your cost is chiefly which of them you're in. After that it is the ratio — how much petrol got in against how much that tank takes — and then where the car is and whether a van can reach it safely.
Three questions come first, before quoting, rather than after — what went in, how much, has it run — and that is the reason. Those replies change a range into a straight figure.
About Calcott and its setting
Calcott is a small hamlet in Shropshire, situated inland at an elevation of around 80 metres. Calcott lies near the villages of Bicton Heath and Bicton, and is close to the larger settlement of Shelton. Calcott is characterized by its predominantly flat housing stock, and is home to a population of approximately 540 residents. Calcott is located near the Welsh border, with the city of Wrexham being the nearest urban centre, about 24 miles away.
Calcott and Shropshire: where our fuel drain cover runs
Bicton Heath, Bicton and Shelton are among the places near Calcott that the same vans work, answering petrol in diesel calls across Calcott's SY postcode area. No need to bring the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
At the pump around Calcott, still?
Then you're in the best spot there is. Keep it off. Call.