Bordesley Green: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, provided it has not been started. "Have I ruined it?" is the first question anyone around Bordesley Green asks, and the honest answer is usually no, since petrol left in a diesel tank hurts nothing until it's drawn through the fuel system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to ring, with your engine left off, so it stays that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and ways to make sure you don't repeat it.
What petrol in a diesel does to the engine
On its way through a motor, diesel has two tasks. Lubricating comes before burning; it does both. What stops the surfaces inside your high-pressure pump and your injectors from wearing down against each other is the diesel passing through them — they are designed to very fine clearances.
Of those two jobs, petrol manages the first poorly and the second never. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and strips out the protection the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the clattering starts.
Seen together, they show the shape the problem has. It is movement that causes the harm, not contact. Petrol in the tank is a fuel fault. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors further on.
How bad is petrol in a diesel? Four situations our engineers see around Bordesley Green
Fuelled but never started — the best it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol kept inside that tank alone, it is cleared and flushed on the spot, and nothing more is needed.
Started for a second, or only the ignition on. The system has been bled, so petrol has left the tank and got to the fuel filter and your lines. Normally nothing more than emptying, cleaning and sorting your filter, so still easy.
Driven a few miles. Now your pump has spent these miles labouring on weakened fuel. Mileage is only half of it; how hard it was driven counts equally. Either way this work includes the tank, the lines, your filter and clean fuel through the entire circuit. The school run to Marlborough Primary School is one matter. Any mileage on the Aston Expressway, under 3 miles from Bordesley Green, means your engine working hard throughout, and a run to Birmingham, under 3 miles away, is a very different task as well.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. The engine is telling you the fuel is no longer behaving like diesel. Pull up wherever you are — the verge on First Avenue, a lay-by, a side street — and leave it there. Long-term damage is very unusual when a vehicle is pulled over quickly, and the fuel drain and flush-through that still come first take care of it.
Myths Bordesley Green motorists 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." Nothing is removed when you top up — your tank simply carries more of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. Smaller components and higher pressure are how a current diesel runs its fuel, and that makes the lubrication count more, not less.
The myth that catches drivers out: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the damage stops with them. Feed petrol to a diesel and it normally starts, idles and pulls away like nothing has happened — all the while its pump is wearing. Running does not mean fine.
An old fix for a separate issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol thinned is put back by it — and afterwards, your tank still contains that petrol.
Once your engine has been run, part of the petrol sits in the filter and the fuel lines, not that tank — and your next start sends it straight back through the pump. So the myth "drain the tank yourself and you're sorted" does not hold. And, a can of petrol drained at the roadside is genuinely hazardous.
Why petrol in a diesel happens so easily
Nobody does it on purpose, and it's seldom carelessness. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol vehicle. That is how the forecourt makes it simple.
When habit and the car stop matching, it happens. Hire cars, courtesy cars, and vehicles that are new to you. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. Fuelling up in a rush en route to Adderley Park, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: precisely when it takes place. Throw in rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Preventing petrol in a diesel next time you fill up around Bordesley Green
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust the label on the petrol pump, not the colour.
- Plenty of cars state the fuel inside the filler flap or on the cap, and so check it on your first fill in any motor you do not know.
- One of each in the house? Mark your key to your diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- It sounds silly and it works: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, so put your phone away and keep your mind on the petrol pump.
- Some diesels come with a filler built to block a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Less petrol means a weaker blend, so stop as soon as you realise — though remembering that your next stage is unchanged. It's still not to crank it.
Bordesley Green: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't fire it up, and do not turn the ignition on. Ask the staff to help you roll it away from the pump if you are still at the forecourt, whether that is Gulf or anywhere else. Next, 0333 366 0103. We will ask what went in, roughly how much, and if it has been run.
Say so if it was AdBlue instead of petrol: it is a separate fault, with its own page for Bordesley Green, because AdBlue brings corrosion and deposits instead of lost lubrication.
One petrol in a diesel task in Bordesley Green costs more than another. Why?
There is no fair single price for this, because the four situations above are four different jobs. The situation itself does most of the work of moving the cost. The ratio counts next, meaning how much of the tank is petrol, and then the position of the car and whether getting to it is safe for a van.
Three queries come first, before any quote, instead of after — what was put in, how much, has it run — and this is the reason. Those answers change a range into a straight figure.
About Bordesley Green and where it is
Bordesley Green is a suburban area in the West Midlands, situated approximately 2.3 miles east of Birmingham city centre. Bordesley Green sits at an elevation of around 134 metres, in a densely populated part of the region. Bordesley Green is characterized by its predominantly terraced housing stock, with nearby areas including Little Bromwich and Saltley. Bordesley Green is home to a sizable population of around 20,637 residents.
Bordesley Green and West Midlands: where our fuel drain cover reaches
Our vans answering petrol in diesel call-outs in Bordesley Green, in the B postcode area, also work the places around it, Little Bromwich, Bordesley Green East and Saltley included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers drain, and the vehicle does not need to move to us.
Still at the pump in Bordesley Green?
Nothing beats it: that is where you are. Leave the vehicle turned off, and ring.