Tan Hills: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — provided no one has started the vehicle. Petrol sitting in a diesel tank does nothing to your engine until something draws it through the system — your ignition priming the pump, the starter, or driving on its own. So the honest answer to the first question anyone around Tan Hills asks, "have I wrecked it?", is usually no. Petrol in Diesel is who to phone, with the motor left off, so it stays that way. Read on for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and ways to make sure you never repeat it.
Petrol in a diesel: what does it do to the engine?
Two jobs fall to diesel on its journey through a motor. It combusts, and before it ignites it protects. Very fine tolerances are built into your injectors and the high-pressure fuel pump, and just your diesel running through keeps their surfaces from grinding together.
The second job petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump on that mixture wearing itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Taken together, they make clear what shape the trouble takes. It's movement that does the harm, not contact. A tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, borne by the fuel, into your injectors further along, which is why a pump that has been working on the petrol is where a mechanical issue starts.
How bad is petrol in a diesel? Four situations our engineers see around Tan Hills
Fuelled up, not once started. The best case there can be. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held inside the tank alone, it's emptied and flushed on the spot, and nothing more is needed.
Started for a moment, or only your ignition on. Petrol has left the tank and got to your filter and the lines, since the system has been bled. That's usually still a simple job — a drain, a flush, and the filter dealt with.
Some miles driven, and the pump has spent each of them labouring on weakened fuel. Tank, lines, filter, then fresh fuel put through the whole system: that's the work, and the way the vehicle was driven counts as much as the miles. On the school run to Nettlesworth Primary School, the distance is short. Getting as far as Durham, under 5 miles away, makes a very different task — as does any mileage on the A1(M), under 3 miles from Tan Hills, with your engine running hard all the way.
Driven on until it complained — rattling, smoke, a ragged idle, a soft throttle. What you are hearing is the motor reporting fuel that no longer acts like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Tanmeads. The fuel drain and flush-through still come first, and they take care of it: if a car is stopped soon, long-term damage is very unusual.
Tan Hills motorists and the petrol in a diesel myths they hear
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 are left with a fuller tank, still the same mix. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. A current diesel sends its fuel through more precise parts at higher pressure, which makes the protection matter more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally won't run, so the driver stops — and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump grinds. Fine and running aren't the same at all.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. That petrol is still inside that tank after that, and whatever it has thinned is not put back.
The next start sends petrol back round your pump out of your lines and your filter, where some of it ends up once the motor has run. That's why draining the tank yourself does not leave you sorted — a myth. And, a can of petrol filled by the kerbside is truly hazardous.
Petrol in a diesel: how does it happen?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol car at all. So the mistake runs one way.
The moment routine stops matching your car is the moment it takes place. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps suddenly in a different order. Fuelling up in a rush on the way to Chester-Le-Street, with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it takes place. The hand repeats what it has always done when you add rain, a phone call or a back seat full of children.
Avoiding petrol in a diesel next time you fill up in Tan Hills
- Read the petrol 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.
- Check the filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on your first fill in a car you don't know.
- Label the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car gets its first tank. It seems daft. It does the trick.
- While you are thinking about something else, this is an easy mistake to make — so tuck the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to reject a petrol nozzle, and add-on devices are available for vehicles without one. They are a backstop, not a reason to stop reading the petrol pump.
- Spotting it halfway? Stop there and then. A weaker blend follows from less petrol inside that tank, but your next step remains the same: don't fire it up.
Put petrol in a diesel in Tan Hills already?
Short and simple, then, is the order of things. Don't switch the ignition on, and do not crank it. Still at the forecourt, at Plawsworth Service Station or anywhere else? Ask the attendants to help you roll the car clear of the petrol pump. Call 0333 366 0103 next, with three facts — the fuel, the rough quantity, and whether it has run.
Say so if it was AdBlue instead of petrol: it's a different fault, with its own page for Tan Hills, since AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel job in Tan Hills costs more than another. Why?
The four situations above are four separate jobs, so no single quote for this would be fair. The scenario itself does most of the work of moving the cost. Where the vehicle is matters too, and whether our van can safely reach it, after the ratio of petrol to what your tank holds.
Before any quote, not after, we ask three questions: your fuel that got in, its amount, and if it has run. That's why. Given those answers, there is a straight figure instead of a range.
About Tan Hills, for a moment
Tan Hills is a village situated on the riverside in County Durham, with a population of around 899 residents. Tan Hills has a mix of housing types, but semi-detached homes are the most predominant. Tan Hills is located near several other small villages, including Nettlesworth, Kimblesworth, and Plawsworth Gate, and is approximately 3 miles from the city of Durham. Tan Hills sits at an elevation of 98 metres above sea level, in a scenic area of the North East region.
Fuel drain cover in Tan Hills and across Durham
Petrol in diesel jobs around Tan Hills — part of the DH postcode area — go to vans that likewise cover the spots about it, Nettlesworth, Kimblesworth and Plawsworth Gate among them. Our technicians drain wherever your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump around Tan Hills, right now?
Nothing beats it: that's where you now are. Keep it off. Ring.