Petrol in a Diesel Car in Spout Green: How Worried Should You Be?
Likely less than you are now — provided no one has started the car. Petrol sitting in a diesel tank does nothing to your engine until something pulls it through your fuel system — the ignition priming the pump, the starter, or the drive itself. So the fair answer to the first question everyone in Spout Green asks, "have I wrecked it?", is normally no. Leave your motor off and ring Petrol in Diesel — that keeps it like that. What petrol actually does to a diesel, how to judge how far it has gone, and how to keep it from happening a second time: that is the rest of this page.
The engine and petrol in a diesel: what goes on
On its way through an engine, diesel has two jobs. Before it combusts, it lubricates — and then it ignites. Very fine clearances are built into the injectors and the high-pressure pump, and only your diesel running through stops their surfaces grinding together.
The second job petrol does not do at all, and the first it does poorly. It's thinner than diesel and takes away the protection the fuel system rests on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Seen together, they show what shape the issue takes. Not contact but circulation is what does the damage. A tank with petrol in it is a fuel issue. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
Spout Green, petrol in a diesel: four situations, from mild to significant
Filled up, and not started: no case is better. On a forecourt, and truly only there, that petrol is still limited to that tank — because anywhere else the vehicle was driven to get to it. The task is draining and purging on the spot.
Ignition on, or started for a second. Petrol has come out of that tank and got to your filter and the lines, since your system has been primed. That is normally still an easy job — a drain, a flush, and your filter dealt with.
Your pump now spent a couple of miles on thinned fuel — that is what driving the vehicle does. Tank, lines, filter, then fresh fuel run through the entire system: that's the work, and the way the vehicle was driven counts as much as the mileage. Short trips, such as the school run to Mottram CofE Primary School, are one thing. Any distance on the M67, under a mile from Spout Green, means your engine working hard throughout, and a run to Manchester, under 10 miles away, makes a very different job as well.
Driven on until it protested — clattering, smoke, a lumpy idle, a dead throttle. The fuel is not behaving like diesel any more, and the motor is saying so. Pull up where you are — on the verge on Tollemache Road, at the kerb, down a side road — and do not move it again. What comes first is still the drain and flush-through, and that sorts it out, with long-term damage very uncommon when a car is stopped quickly.
What Spout Green people get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up takes out nothing; it gives you a fuller tank of the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that guidance assumes.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through finer parts: that's how a current diesel moves its fuel, and so the protection counts for more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it usually will not run, and so the motorist stops — and the harm 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 grinds. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old fix for a separate problem. It does not put back what petrol has weakened, and the petrol is still inside that tank later on.
If your engine has run, part of the petrol sits in the filter and the lines, not the tank — and the next start pulls it right back through the pump. So the myth "drain that tank yourself and you are sorted" does not stand up. Draining petrol into a can at the kerbside is also really hazardous.
How it happens: petrol in a diesel
Carelessness is seldom the cause, and no one means to do it. One way only, because of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol motor. That's how the forecourt makes it straightforward.
It takes place when routine and the car stop matching. Any car that is new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to Broadbottom. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Renault Clio for the first time. Add a back seat full of kids, a phone call or rain, and habit takes over.
Preventing petrol in a diesel next time you fill up in Spout Green
- Check the petrol 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.
- Plenty of vehicles state the fuel inside the filler flap or on the cap, and so check it on the first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It sounds silly and it does the trick.
- Mistakes like this are straightforward to make while your mind is on something else, and so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop checking the pump.
- Noticing it mid-fill? Stop there and then. A weaker blend results from less petrol in your tank, but your next step remains the same: do not start it.
Petrol already in a diesel in Spout Green? Start here
In that case, there's only a short order of things. Never fire it up, and do not turn your ignition on. Ask the staff to help you roll it away from the petrol pump if you're still on the forecourt, whether that's Shell or somewhere else. Ring 0333 366 0103 next, with three facts — the fuel, the approximate quantity, and if it's run.
Say so if it was AdBlue instead of petrol: it is a different problem, with its own page for Spout Green, since AdBlue brings corrosion and deposits instead of lost protection.
What makes one Spout Green petrol in a diesel task cost more than the next
The four situations above are four different jobs, so no single quote for this would be honest. What shifts the cost is chiefly which of them you are in. Where the car is counts too, and whether a van can safely get to it, after the ratio of petrol to what your tank takes.
What got in, how much, and if it has run — three queries our technicians ask before costing, not after, for exactly that reason. Given those answers, there is a straight figure instead of a range.
About Spout Green itself
Spout Green is a suburban area in Greater Manchester, situated on the riverside at an elevation of 226 metres. Spout Green lies approximately 9.6 miles east of Manchester, near the communities of Lower Roe Cross, Roe Cross, and Mottram in Longdendale. Spout Green is characterised by its predominantly detached housing stock, reflecting its residential nature.
Fuel drain cover in Spout Green and across Greater Manchester
Petrol in diesel calls around Spout Green — part of the SK postcode area — go to teams that likewise cover the locations round it, Lower Roe Cross, Roe Cross and Mottram in Longdendale included. The car doesn't need to come to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Spout Green and still at the pump?
Then you're in the best position there can be. Call, and leave it switched off.