Petrol in a Diesel Car in Wyken Green: How Worried Should You Be?
Likely less than you are now — provided no one has started the vehicle. Everyone in Wyken Green starts with "have I ruined it?", and the fair answer is generally no: petrol left inside the tank of a diesel stays harmless till priming, cranking or driving draws it into the system. Leave your motor off and phone Petrol in Diesel — that keeps it like that. Further down, this page sets out what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you a second time.
The engine and petrol in a diesel: what goes on
Two jobs fall to diesel on its journey round a motor. Before it combusts, it protects — and then it burns. The high-pressure fuel pump and the fuel injectors are designed to extremely fine gaps, and your diesel passing through them is what keeps those surfaces from wearing against one another.
The second job petrol does not do at all, and the first it does badly. It's runnier than diesel and strips away the lubrication the system depends on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Put those together and the shape of the trouble is plain. Contact doesn't do the damage — movement does. 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 your fuel to your injectors downstream.
Four situations our technicians see in Wyken Green: how bad is petrol in a diesel?
The best case there is: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With that petrol held in your tank alone, it's drained and purged on the spot, and nothing more is needed.
Ignition on, or started for a second. Once primed, your system has drawn petrol out of your tank as far as the filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually easy.
Driven a few miles. Now the pump has spent these miles labouring on thinned fuel. How hard the car was driven matters as much as how far, and the work covers your tank, your lines, your filter and fresh fuel through the whole system. Driving the children to St John Fisher Catholic Primary School is one kind of trip. Driving as far as Coventry, under 3 miles away, makes a very different job — as does any miles on the M6, under 3 miles from Wyken Green, with the motor running hard all the way.
Driven on till it protested — knocking, smoke, an uneven idle, a dead throttle. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Whether it is the verge on Derbyshire Way, a lay-by or a side street, stop there and leave it. The drain and flush still go first, and they sort it out: if a car is stopped quickly, long-term damage is very unusual.
Myths Wyken Green people 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 by topping up — you're left with a bigger tank, still the same mix. The assumption behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. Rather, the opposite. Smaller parts and higher pressure are the way a newer diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no damage done." The driver of a petrol motor fed diesel usually stops, because it will not run, and the harm stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile your pump grinds. A running engine doesn't mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an old fix for a separate problem. That petrol is still inside the tank afterwards, and whatever it has diluted isn't put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in the filter and lines, ready to go right back through the pump at your next start. Also, a can of petrol drained by the kerbside is truly hazardous.
How it happens: petrol in a diesel
It's seldom carelessness, and nobody does it on purpose. One way only, since of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol vehicle. That's how the forecourt makes it simple.
When habit and the car stop matching, it happens. Courtesy car, hire car, or a vehicle that's new. Two cars on one drive, one petrol, one diesel. A familiar forecourt with the pumps in a different order. Fuelling up in a hurry on the way to Coventry Arena, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to prevent petrol in a diesel at your next fill-up in Wyken Green
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what matters.
- The first fill in an unfamiliar car is the time to check the filler flap — on it, or on the cap, plenty of vehicles state which fuel to use.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key when a house has one of each. So mark it.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It sounds daft and it works.
- Tuck your phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels have a filler built to reject 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 makes a thinner blend, and so stop as soon as you realise — while remembering that your next stage is unchanged. It's still not to fire it up.
Already put petrol in a diesel around Wyken Green?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. Ask the attendants to help you roll it away from the petrol pump if you are still at the forecourt, whether that's Murco or anywhere else. Next, 0333 366 0103. We'll ask what went in, about how much, and if it has been run.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Wyken Green page.
One petrol in a diesel job in Wyken Green costs more than another. Why?
The four situations above are four different jobs, so no single quote for this would be honest. The situation itself does most of the work of moving your cost. Where your car is counts too, and whether a technician can safely get to it, after the ratio of petrol to what that tank takes.
That's why we ask three questions before pricing instead of after: what got in, how much, and whether it's run. Given those replies, there is a straight figure rather than a range.
About Wyken Green, briefly
Wyken Green is a suburban area located on the River Sowe in the West Midlands, with a mix of terraced housing and local amenities. Wyken Green sits near the city of Coventry, approximately 2 miles from the city centre, and is close to other nearby places such as Court House Green and Bell Green. Wyken Green has a population of around 7536 people and is situated at an elevation of 88 metres, with the River Sowe running along its edge.
Fuel drain cover in Wyken Green and across West Midlands
Petrol in diesel jobs in Wyken Green — part of the CV postcode area — go to vans that likewise cover the spots about it, Court House Green, Bell Green and Henley Green among them. The car doesn't need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Wyken Green and still at the petrol pump?
Nothing beats it: that's where you are. Turned off it remains; then call.