Grendon: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry less than you likely are. Petrol sitting in a diesel tank does nothing to the engine until something pulls it through the system — the ignition priming your pump, the starter, or the drive on its own. So the fair answer to the first question anyone around Grendon asks, "have I ruined it?", is generally no. Leave your engine off and phone Petrol in Diesel — that is how you keep it like that. Read on 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 repeat it.
Petrol in a diesel: what does it do to the motor?
Diesel has two tasks on its way through an engine. It protects first, and after that does it burn. Extremely fine tolerances are built into your injectors and the high-pressure pump, and only the diesel flowing through keeps their surfaces from grinding together.
The second task petrol doesn't do at all, and the first it does poorly. A pump running on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any knocking comes.
Combined, those make the shape of the issue clear. Contact does not do the damage — circulation does. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, borne by the fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault begins.
How serious is petrol in a diesel? Four situations we see in Grendon
The best case there is: filled up, not once started. Just that tank has petrol in it, so the task is draining that tank and purging the fuel system where your car stands. This situation can only really take place on a forecourt: anywhere else, the vehicle got there by being driven.
A brief spell of running, or merely your ignition on. Petrol has left your tank and reached your filter and the fuel lines, since the fuel system has been primed. That is usually still a simple task — a drain, a flush, and your filter dealt with.
Driven a few miles. Now the pump has spent these miles running on diluted fuel. How hard the vehicle was driven counts as much as how far, and the work covers the tank, your lines, the fuel filter and clean fuel through the entire circuit. The school run to Woodside CofE Primary School is one matter. A run as far as Lichfield, under 15 miles away, is a very different job. So is any mileage on the M42, under 3 miles from Grendon, where the engine has been working hard the whole time.
Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. The motor is telling you your fuel is no longer behaving like diesel. Pull up wherever you are — the verge on Spon Lane, a lay-by, a side street — and leave the vehicle there. The drain and flush-through still come first, and they take care of it: when a vehicle is pulled over soon, long-term damage is very uncommon.
Grendon people and the petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It doesn't. A fuller tank of the same mix is all it gives, because topping up removes nothing. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
Not so: a newer diesel copes with a bit of petrol. If anything, the reverse. A newer diesel sends its fuel through smaller components at higher pressure, which makes the lubrication matter more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there's no harm done." The driver of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the harm stops with them. While your pump grinds, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an outdated fix for a separate problem. It doesn't put back what petrol has weakened, and the petrol is still in that tank after that.
The next start sends petrol back round the pump out of the fuel lines and your filter, where some of it sits once the motor has run. That's why draining your tank yourself does not leave you sorted — a myth. On top of that, petrol drained into a can by the road is truly hazardous.
Why petrol in a diesel takes place so easily
No one does it on purpose, and it's seldom carelessness. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
Routine and the car falling out of step is how it occurs. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. Racing for a train outside Atherstone and filling up en route. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. Add 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 in Grendon: avoiding petrol in a diesel
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the pump, not the colour.
- Inspect the filler flap. Plenty of vehicles state the fuel type inside the flap or on the cap. Look at it on the first fill in any car you do not know.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a household has one of each. So label it.
- It seems silly and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the pump.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that will not take a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- Stop the moment you realise. Less petrol inside your tank makes a weaker mixture. It does not change what to do next, which is still not to start the car.
Put petrol in a diesel around Grendon already?
Then, there is only a short order of things. Starting it is out, and so is switching on the ignition. Yet on the forecourt, at Asda Express or anywhere else? Ask the staff to help you push the vehicle away from the petrol pump. Phone 0333 366 0103 next, with three facts — the fuel, the rough amount, and whether it has run.
If it was AdBlue rather than petrol, say so. That is a different fault — corrosion and deposits instead of lost lubrication — and it has its own page for Grendon.
One petrol in a diesel job around Grendon costs more than another. Why?
The four situations above are four different jobs, so no single price for this would be honest. What moves your cost is mostly which of them you're in. Next it's the share — how much petrol got in against how much that tank holds — and after that where the car is and whether our van can get to it safely.
That's why we ask three questions before quoting instead of after: what was put in, how much, and if it's run. Their replies are what change a range into one firm number.
About Grendon and where it is
Grendon is a village in Warwickshire, situated on the riverside at an elevation of around 75 metres, with Grendon Common nearby. Grendon lies approximately 11.5 miles from Lichfield and 97.5 miles northwest of London, in a rural area that includes nearby Baddesley Ensor and Dordon. Grendon has a population of around 906 people, predominantly living in detached houses. Grendon is characterized by its quiet, rural setting and residential community.
Fuel drain cover across Warwickshire, Grendon included
Grendon Common, Baddesley Ensor and Dordon are among the locations around Grendon that the same vans work, answering petrol in diesel call-outs across Grendon's CV postcode area. The car does not need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Grendon: still at the petrol pump?
In that case, you couldn't be in a better place. Switched off it remains; then ring.