How Worried Should You Be? Petrol in a Diesel Car in Mill Green
Far less than you likely are, provided it hasn't been started. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through the fuel system — the ignition priming the pump, the starter, or driving on its own. So the fair answer to the first question anyone in Mill Green asks, "have I wrecked it?", is normally no. Petrol in Diesel is who to call, with your engine kept off, so it remains that way. What petrol really does to a diesel, how to gauge how far it's travelled, and how to stop it from happening a second time: that is the rest of this page.
Inside the engine: what petrol in a diesel does
Two jobs fall to diesel on its journey round a motor. It ignites, and before it burns it lubricates. The high-pressure fuel pump and the fuel injectors are designed to extremely fine tolerances, and your diesel passing through them is what keeps those surfaces from grinding against each other.
Petrol does the first task badly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump on the mixture wearing itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the clattering.
Together, those leave the shape of the issue clear. Contact doesn't do the harm — movement does. Petrol in a tank is a fuel issue. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Four scenarios our engineers see around Mill Green: how bad is petrol in a diesel?
Fuelled, and not started: no case is better. On a forecourt, and truly only there, that petrol is still confined to your tank — because anywhere else the car was driven to get to it. The task is draining and purging on the spot.
The ignition turned on, or a brief start. The fuel system has been bled, and so petrol has left that tank and reached your filter and the fuel lines. Drain, flush, deal with your filter: still normally straightforward.
Those few miles driven were the pump running on fuel thinned by petrol throughout. The work is the tank, your lines, the filter and fresh fuel through the entire circuit, and how hard the car was driven counts as much as how far. Driving the kids to St Mary's Catholic Primary School is one kind of trip. Getting as far as Lichfield, under 10 miles away, makes a very different task — as does any mileage on the M6 Toll, under a mile from Mill Green, with the engine labouring hard the whole time.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The fuel is not behaving like diesel any more, and the motor is telling you. Leave it where it has stopped: a lay-by, a quiet street, the verge on Surrey Close. What comes first is still the drain and flush-through, and that deals with it, with long-term damage very unusual when a vehicle is stopped quickly.
Petrol in a diesel stories Mill Green drivers hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed by topping up — you're left with a fuller tank, still the same mixture. That guidance supposes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Smaller components and higher pressure are how a current diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that catches people. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor usually leaves a motor that won't run: the motorist stops, and so does the harm. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Running isn't the same as fine.
An outdated workaround for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has thinned stays weakened, and that petrol remains inside that tank regardless.
Myth: "Drain that tank yourself and you are sorted." After the engine has been run, some of that petrol is no longer in that tank: it is in the filter and your lines, and it goes right back through your pump at the next start. It's also really dangerous to drain petrol into a can at the kerbside.
How does petrol in a diesel take place?
Nobody does it on purpose, and it is seldom carelessness. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it easy, and the mistake runs one way.
The moment habit stops matching the car is the moment it occurs. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the drive of the same household. The pumps in a different order on a well-known forecourt. A train to catch, and a hurried fill on the way to Cannock. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is precisely the moment it happens. Add rain, a phone call or a back seat full of children, and your hand does what it has always done.
How to prevent petrol in a diesel at your next fill-up in Mill Green
- The label is what matters, so read the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- In a motor you don't know, look inside the flap over the filler or at the cap before the first fill: plenty of motors state the fuel type there.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, for a home with one of each.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It sounds silly. It does the trick.
- Tuck your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels come with a filler built to block a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- Less petrol means a weaker blend, and so stop the moment you realise — though remembering that the next step is unchanged. It's still not to fire it up.
Mill Green: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't turn your ignition on, and do not fire it up. The attendants at the forecourt — whether at Asda itself or wherever you filled up — will usually help roll it away from the pump if you ask. What was put in, roughly how much, and whether it has run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a separate fault, with its own page for Mill Green, because AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel job in Mill Green costs more than another
The four situations above are four different jobs, so no single quote for this would be fair. The situation itself does most of the work of moving your cost. Where the car is counts too, and whether our van can safely get to it, after the share of petrol to what the tank holds.
What went in, how much, and if it has run — three questions our engineers ask before pricing, not after, for precisely that reason. Those answers turn a range into a straight figure.
About Mill Green
Mill Green is a suburban area in Staffordshire, situated on the riverside with a mix of residential and natural environments. Mill Green has a relatively low elevation of 135 metres and is located near several other communities, including Rumer Hill and Hawks Green. Mill Green is also close to the city of Lichfield, which is about 8 miles away, and is part of the larger West Midlands region. Mill Green is predominantly composed of flat housing, which is common in many suburban areas in England.
Fuel drain cover across Staffordshire, Mill Green included
Rumer Hill, Hawks Green and Cannock are among the locations around Mill Green that the same vans work, answering petrol in diesel jobs across Mill Green's WS postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all spots we drain, and the car doesn't need to come to us.
Mill Green: still at the petrol pump?
The best position there is, then — that is where you are. Switched off it remains; then call.