How Worried Should You Be? Petrol in a Diesel Car in Walkers Heath
Far less than you likely are, provided it hasn't been started. Till your ignition primes the pump, the starter cranks, or the vehicle is driven, petrol in a diesel tank just waits there and does nothing. Which means the honest reply to that first Walkers Heath query — "have I wrecked it?" — normally no. Keep it that way: leave the engine off then phone Petrol in Diesel. The remainder of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
Inside the motor: what petrol in a diesel does
Diesel does two jobs on its way through an engine. It ignites, and before it burns it protects. The high-pressure fuel pump and your injectors are designed to extremely fine clearances, and the diesel passing through them is what keeps those surfaces from wearing down against one another.
The second task petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on that mixture wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the rattling.
The shape of the trouble is plain once you put those together. Contact does not do the damage — circulation does. All a tank with petrol in it amounts to is a fuel fault. After the pump has been labouring on that petrol, a mechanical fault has started: whatever is shed by a pump that's grinding is carried onward to the fuel injectors with your fuel.
Four situations we see around Walkers Heath: how serious is petrol in a diesel?
Filled up, and never started: no case is better. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With that petrol kept inside that tank alone, it's drained and rinsed on the spot, and nothing more is needed.
Started for a second, or just your ignition on. Once primed, the fuel system has pulled petrol out of that tank up to the filter and the lines. Still normally simple: drain, flush, and the filter sorted.
A couple of miles driven, and your pump has spent every one of them labouring on thinned fuel. Distance is only half of it; how hard it was driven counts equally. Either way this work includes that tank, the lines, your filter and clean fuel through the whole circuit. Driving the kids to St Paul's Catholic Primary School is one kind of trip. Any mileage on the M42, under 5 miles from Walkers Heath, means the motor has worked hard throughout, and a run to Birmingham, under 10 miles away, is a very different job too.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. The fuel is not behaving like diesel any more, and your motor is telling you. Leave it wherever it stops: a lay-by, a quiet street, the verge on Vista Green. Long-term damage is very rare when a car is stopped early, and the fuel drain and flush that still come first deal with it.
What Walkers Heath motorists get told about petrol in a diesel — and the stories in it
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." Finer components and higher pressure are how a newer diesel runs its fuel, and that makes the protection matter more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools motorists. The motorist of a petrol motor fed diesel usually stops, since it will not run, 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 your pump wears. Fine and running aren't the same at all.
An outdated fix for a different issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." It doesn't put back what petrol has thinned, and that petrol is still in the tank afterwards.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, ready to go straight back through your pump on the next start. Draining petrol into a can at the roadside is also truly dangerous.
How does petrol in a diesel take place?
Nobody does it on purpose, and it's seldom carelessness. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol car. That is how the forecourt makes it straightforward.
The moment habit stops matching the car is the moment it happens. Hire cars, courtesy cars, and vehicles that are new to you. Two motors on one drive, one petrol, one diesel. A familiar forecourt with the pumps in a different order. Fuelling up in a rush on the way to Kings Norton, with a train to catch. A new-to-you diesel Skoda Octavia, its first fuelling, and a motorist used to petrol: precisely when it happens. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up around Walkers Heath
- Read the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what matters.
- Inspect the filler flap. Many cars state the fuel type inside the flap or on the cap. Look at it on your first fill in any motor you don't know.
- Mark the key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car needs its first tank. It seems daft. It does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck your phone away then keep your mind on the pump.
- Add-on devices are available for motors without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Noticing it halfway? Stop there and then. A weaker blend results from less petrol in that tank, yet the next step remains the same: do not fire it up.
Already put petrol in a diesel around Walkers Heath?
Short and simple, then, is the order of things. Don't turn your ignition on, and don't fire it up. If you are still at the forecourt — BP or anywhere else — ask the attendants to help you roll the vehicle away from the pump. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it's been run.
Corrosion and deposits form the trouble with AdBlue, where petrol brings lost lubrication. So if it was AdBlue, say so — and see its own Walkers Heath page.
What makes one Walkers Heath petrol in a diesel job cost more than the next
The four scenarios above are four different jobs, so no single quote for this would be fair. What moves your cost is mostly which of them you are in. The ratio matters next, meaning how much of that tank is petrol, and then the location of your car and whether getting to it is safe for our van.
What went in, how much, and if it's run — three questions our technicians ask before costing, not after, for precisely that reason. Those answers turn a range into a straight figure.
About Walkers Heath
Walkers Heath is a locality in the West Midlands, situated near the River Rea and close to the cities of Birmingham and its surrounding suburbs. Walkers Heath sits at an elevation of around 160 metres, with nearby places including Kings Norton, Lifford, and Brandwood End. Walkers Heath has a population of approximately 4179 people, predominantly living in semi-detached housing. Walkers Heath is located about 5.2 miles southwest of Birmingham city centre, and around 98.3 miles northwest of London.
Across West Midlands and in Walkers Heath: fuel drain cover
Kings Norton, Lifford and Brandwood End are among the locations around Walkers Heath that the same vans work, answering petrol in diesel calls across Walkers Heath's B postcode area. The vehicle doesn't need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the pump in Walkers Heath, right now?
In that case, you couldn't be in a better place. Switched off it remains; then call.