Tideswell: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, provided it has not been started. Petrol resting in a diesel tank does nothing to your engine until something draws it through the system — the ignition priming your pump, your starter, or the drive on its own. So the truthful answer to the first question anyone around Tideswell asks, "have I wrecked it?", is normally no. Keep it that way: leave your engine off then phone Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's gone, and how to stop it from happening again: that's the rest of this page.
Inside your engine: what petrol in a diesel does
Passing through a motor, diesel is doing two things at the same time. Before it ignites, it lubricates — then it burns. Your high-pressure pump and the injectors are built to extremely fine tolerances, and the diesel passing through them is what stops those surfaces from wearing down against one another.
Poorly at the first, not at all at the second: that is petrol. A pump working on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the protection the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where any rattling comes.
The shape of the issue is plain once you put those together. It is movement that does the harm, not contact. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds goes on, carried by the fuel, into your injectors further along, which is why a pump that has been working on the petrol is where a mechanical problem starts.
How bad is petrol in a diesel? Four situations our engineers see in Tideswell
Filled up, not once started. The best case there can be. That petrol is inside your tank and just your tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only truly happen on a forecourt, as anywhere else your car has been driven to get there.
A moment's running, or merely your ignition on. Once primed, the system has drawn petrol out of the tank up to your filter and the fuel lines. That is usually still an easy job — a drain, a flush, and your filter dealt with.
Driven a couple of miles. Now the pump has spent these miles working on thinned fuel. The work is that tank, the lines, the filter and fresh fuel through the entire system, and how hard the vehicle was driven matters as much as how far. The school run to Bishop Pursglove CofE (A) Primary School is one matter. Driving as far as Sheffield, under 15 miles away, makes a very different job — as does any mileage on the M67, under 25 miles from Tideswell, with your engine running hard all the way.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. That is the motor telling you its fuel has stopped behaving like diesel. Pull up where you are — on the verge on High Street, at the kerb, down a side road — and do not move it. What comes first is still the drain and flush-through, and that sorts it out, with lasting damage very unusual when a vehicle is stopped soon.
Myths Tideswell people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed when you top up — that tank simply carries more of the same mixture. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the reverse. Finer components and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication matter more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor usually means a motor that won't run: the motorist stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile the pump grinds. Fine and running aren't the same at all.
Myth: a two-stroke additive lets you to drive home. It is an old fix, meant for another problem. None of what petrol diluted gets put back by it — and afterwards, that tank still holds that petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in the filter and lines, waiting to go straight back through the pump on your next start. And, a can of petrol drained by the kerbside is truly hazardous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle mostly will not go into a petrol car, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error simple, and only in that direction.
When routine and the vehicle stop matching, it takes place. Any car that is new to you — hired, on loan as a courtesy car, or brand new. Two cars on one drive, one petrol, one diesel. Your normal forecourt, its pumps suddenly in a different order. Filling up in a rush en route to Dove Holes, with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. Your hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
Next time you fill up in Tideswell: avoiding petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Trust the label on the petrol pump, not the colour.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before the first fill: many vehicles print the fuel type there.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key if a household has one of each. So label it.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds daft. It does the trick.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Noticing it mid-fill? Stop at once. A thinner mixture results from less petrol inside the tank, yet the next stage remains the same: don't start the car.
Petrol already in a diesel around Tideswell? Begin here
Then, there is only a short order of things. Starting it is out, and so is turning on your ignition. Yet on the forecourt, at UK or anywhere else? Ask the staff to help you push the vehicle clear of the petrol pump. Then ring 0333 366 0103 and tell us what was put in, about how much, and if it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different issue — Tideswell has a page just for it.
Tideswell petrol in a diesel jobs: why one costs more than another
There's no honest single quote for this, since the four situations above are four separate tasks. Mostly, your cost shifts with which situation you are in. Where the car is counts too, and whether our van can safely reach it, after the share of petrol to what the tank takes.
What went in, how much, and if it's run — three questions we ask before pricing, not after, for exactly that reason. Their answers are what change a range into one firm number.
About Tideswell
Tideswell is a village in the Peak District National Park, situated in the heart of Derbyshire at an elevation of 296 metres. Tideswell lies approximately 14.5 miles from Sheffield and is surrounded by nearby villages such as Lane Head, Litton, and Wheston. Tideswell has a population of around 1554 people and predominantly consists of semi-detached housing. Tideswell is located inland, about 140.6 miles from London.
Across Derbyshire and around Tideswell: fuel drain cover
Lane Head, Litton and Wheston are among the locations near Tideswell that the same teams work, answering petrol in diesel call-outs across Tideswell's SK postcode area. The car doesn't need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the petrol pump in Tideswell, right now?
Then, you couldn't be in a better position. Call, and leave it switched off.