Petrol in a Diesel Car in Swain House: How Worried Should You Be?
Less than you probably are, if it has not been started. Petrol sitting in a diesel tank does nothing to the motor till something pulls it through the system — your ignition priming your pump, your starter, or the drive on its own. So the truthful answer to the first question everyone around Swain House asks, "have I wrecked it?", is normally no. Leave the motor off and ring Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has spread, and ways to make sure you never do it again.
Your engine and petrol in a diesel: what happens
Two jobs fall to diesel on its route through a motor. Before it burns, it protects — then it ignites. Extremely fine gaps are built into the injectors and the high-pressure pump, and just the diesel running through stops their surfaces grinding together.
The second task petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump running on the blend wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the knocking.
Put those together and the shape of the problem is plain. Contact doesn't do the harm — circulation does. Where that petrol is only in your tank, it's a fault of fuel, nothing more. Once your pump has been running on that petrol, a mechanical fault has begun: anything shed by a pump that's wearing down is carried downstream to the fuel injectors with your fuel.
Swain House, petrol in a diesel: four cases, from mild to serious
The best case there is: filled up, not once started. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With the petrol kept inside your tank alone, it's drained and flushed on the spot, and nothing more is needed.
The ignition switched on, or a short start. With the fuel system primed, the fuel lines and filter already hold petrol that came from that tank. Usually little more than draining, cleaning and seeing to the filter, so still straightforward.
Those few miles driven meant your pump working on fuel weakened by petrol throughout. Miles is only half of it; how hard it was driven counts equally. Either way this work runs to your tank, your lines, the fuel filter and fresh fuel through the entire system. Short trips, like the school run to Swain House Primary School, are one matter. Any distance on the M606, under 5 miles from Swain House, means the motor has worked hard throughout, and a run to Bradford, under 3 miles away, is a very different job too.
Driven till it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and the engine is telling you. Leave it where it stops: a lay-by, a side street, the verge on Radcliffe Avenue. The drain and flush-through still go first, and they take care of it: if a car is stopped soon, permanent damage is very unusual.
Swain House people and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Topping up takes out nothing; it gives you a fuller tank of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through smaller parts: that's how a current diesel handles its fuel, and so the protection counts more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that catches drivers. Diesel in a petrol motor usually means a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it generally fires up, idles and drives away like nothing happened — all the while its pump is wearing. Fine and running aren't the same at all.
An old workaround for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has weakened stays weakened, and that petrol stays inside that tank anyway.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol lies in the filter and lines, waiting to go straight back through your pump on the next start. Besides, petrol emptied into a can by the road is truly risky.
Petrol in a diesel: how does it occur?
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
Routine and the car falling out of step is when it happens. Courtesy car, hire car, or a car that is brand new. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A hurried fill en route to Frizinghall with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it happens. With rain, a call coming in, or children to deal with, the hand simply does what it has always done.
Preventing petrol in a diesel next time you fill up around Swain House
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- Inspect your filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a household with one of each.
- It sounds silly and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- While you're thinking about something else, this is an easy mistake to make — so tuck your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop checking the petrol pump.
- As soon as you notice, stop: less petrol inside that tank means a thinner mixture. What to do next does not change, though — still do not fire it up.
Swain House: already put petrol in a diesel?
In that case, there's just a short order of things. Do not turn your ignition on, and don't crank it. The attendants on the forecourt — whether at Morrisons itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Call 0333 366 0103 next, with three answers — your fuel, the rough volume, and whether it's run.
If it was AdBlue instead of petrol, say so. That is a different fault — corrosion and deposits rather than lost protection — and it has its own page for Swain House.
Why one petrol in a diesel job around Swain House costs more than another
There's no fair single quote for this, since the four situations above are four different jobs. What shifts your cost is chiefly which of them you're in. Beyond that it is the ratio — how much petrol was put in against how much the tank holds — and after that where your car is and whether our van can get to it safely.
What went in, how much, and whether it has run — three questions our engineers ask before pricing, not after, for exactly that reason. A range turns into a straight figure when those answers are in.
About Swain House
Swain House is a suburban area located near Bradford in West Yorkshire, sitting at an elevation of 198 metres in the inland landscape of the region. Swain House is characterized by its predominantly semi-detached housing stock, reflecting the residential development patterns of the surrounding area. Swain House is situated close to other nearby places such as Moor End, Bolton Outlanes, and Bolton, and is approximately 2.2 miles from the city of Bradford.
Fuel drain cover in Swain House and across West Yorkshire
Swain House rests in the BD postcode area, and our vans that answer petrol in diesel call-outs there work the locations around it as well — Moor End, Bolton Outlanes and Bolton among them. The vehicle 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 driveway.
In Swain House and still at the petrol pump?
The best position there is, then — that is where you are. Keep the car turned off, then ring.