Petrol in a Diesel Car in Gnosall Heath: How Worried Should You Be?
Probably less than you already are — as long as nobody has started the vehicle. "Have I ruined it?" is the first thing anyone around Gnosall Heath asks, and the honest answer is generally no, since petrol resting in a diesel tank hurts nothing till it's drawn through the fuel system — by ignition priming, by your starter, or by driving. To leave the car like that, ring Petrol in Diesel and leave the engine switched off. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and the way to make sure you never do it again.
Inside the motor: what petrol in a diesel does
On its way through an engine, diesel has two jobs. It combusts, and before it combusts it lubricates. Made to extremely fine tolerances, the injectors and your pump depend on your diesel flowing through them to stop their surfaces wearing against one another.
The second task petrol does not do at all, and the first it does badly. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication the fuel system depends on, and any pump running on such a mix is wearing itself.
Together, those make the shape of the trouble plain. It's circulation that does the damage, not contact. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds goes on, borne by the fuel, into the fuel injectors further along, which is why a pump that has worked on that petrol is where a mechanical issue starts.
How bad is petrol in a diesel? Four situations we see in Gnosall Heath
Fuelled up, not once started. The best case there can be. Being at a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With that petrol held inside that tank alone, it's cleared and rinsed on the spot, and nothing more is needed.
Your ignition switched on, or a short start. Petrol has left your tank and reached the fuel filter and your lines, since your system has been bled. Drain, flush, see to the fuel filter: still normally easy.
A couple of miles driven, and the pump has spent each of them working on thinned fuel. Tank, lines, filter, then clean fuel run through the entire circuit: that is the work, and the way your car was driven matters as much as the mileage. A school run to Gnosall St Lawrence Coe Primary Academy is one thing. A run as far as Wolverhampton, under 15 miles away, is a very different job. So is any miles on the M6, under 5 miles from Gnosall Heath, where the motor has been labouring hard the whole time.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. That's your engine telling you its fuel no longer is acting like diesel. Whether it is the verge on Ginger Hill, a lay-by or a side street, stop where you are then leave it. The drain and flush-through still go first, and they sort it out: when a car is pulled over soon, lasting damage is very rare.
Stories Gnosall Heath drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A fuller tank of the same mixture is all you get, since topping up removes nothing. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance supposes.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. A current diesel runs its fuel through smaller parts at higher pressure, which makes the lubrication count more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. A petrol motor fed diesel usually won't run, and so the driver stops and the damage stops with them. Feed petrol to a diesel and it normally starts, ticks over and pulls away like nothing happened — all while its pump is wearing. Being able to run is not proof of being fine.
An old fix for a distinct fault is behind this one. Myth: "Add some two-stroke oil and drive it home." What petrol has diluted remains weakened, and the petrol remains inside that tank regardless.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol sits in your filter and lines, ready to go right back through your pump on your next start. On top of that, petrol emptied into a can by the road is truly hazardous.
How does petrol in a diesel happen?
It is rarely carelessness, and nobody does it on purpose. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol motor at all. So the slip runs one way.
Routine and the car falling out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the drive of the same household. Your usual forecourt, its pumps now in a different order. A train to catch, and a rushed fill on the way to Stafford. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Tiguan for the first time. With rain, a call coming in, or children to deal with, the hand simply does what it always has.
Next time you fill up around Gnosall Heath: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is normal in the UK — yet not on each forecourt. Trust the label on the petrol pump, not the colour.
- In a motor you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of cars state the fuel type there.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So mark it.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It seems daft. It does the trick.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to block a petrol nozzle, and aftermarket devices are available for the rest. Treat it as a safety net, then keep checking the petrol pump.
- As soon as you realise, stop: less petrol in that tank makes a thinner blend. What to do next does not change, though — still do not fire it up.
Gnosall Heath: already put petrol in a diesel?
The order of things is brief, then. Leave it unstarted, with the ignition off as well. The staff at the forecourt — whether at BP itself or wherever you filled up — will normally help roll it away from the petrol pump if you ask. Next, 0333 366 0103. We'll ask what was put in, roughly how much, and if it's been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate fault — Gnosall Heath has a page all for it.
One petrol in a diesel task around Gnosall Heath costs more than another. Why?
The four situations above are four separate jobs, so no single price for this would be fair. Which of them you are in is chiefly what moves your cost. Where the car is counts too, and whether a technician can safely get to it, after the ratio of petrol to what that tank takes.
What went in, how much, and whether it's run — three questions our technicians ask before quoting, not after, for precisely that reason. Given those answers, you get a straight figure instead of a range.
About Gnosall Heath itself
Gnosall Heath is a village situated on the banks of the River Sow in Staffordshire, with a mix of rural and riverside environments. Gnosall Heath has a relatively low elevation of 98 metres above sea level, and is located near the villages of Gnosall and Cowley. Gnosall Heath is characterized by its predominantly detached housing stock, reflecting its status as a residential community.
Fuel drain cover across Staffordshire, Gnosall Heath included
Our teams answering petrol in diesel calls around Gnosall Heath, in the ST postcode area, also work the places near it, Gnosall, Plardiwick and Cowley among them. Our technicians drain where the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the pump in Gnosall Heath, right now?
In that case, you couldn't be in a better place. Keep it off. Phone.