Petrol in a Diesel Car in Thurcaston: How Worried Should You Be?
Not started? Then less worried than you probably are. Petrol resting in a diesel tank does nothing to the engine till something draws it through your fuel system — the ignition priming your pump, your starter, or driving itself. So the fair answer to the first query everyone around Thurcaston asks, "have I ruined it?", is generally no. Petrol in Diesel is who to call, with your motor left off, and so it stays that way. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening a second time: that's the remainder of this page.
What petrol in a diesel does to your engine
Passing through an engine, diesel does two things at once. Oiling comes before burning; it does both. Your high-pressure pump and the injectors are made to very fine tolerances, and your diesel passing through them is what stops those surfaces from wearing against one another.
Of these two tasks, petrol handles the first badly and the second never. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and strips out the protection your fuel system depends on. Petrol is also made to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that is where any clattering comes.
Combined, those make the shape of the trouble plain. It's movement that does the damage, not contact. Where the petrol is only in your tank, it is a problem of fuel, nothing more. After your pump has been labouring on that petrol, a mechanical fault has begun: anything shed by a pump that is wearing is carried downstream to the injectors with your fuel.
Four scenarios our technicians see around Thurcaston: how serious is petrol in a diesel?
Filled but never started — the best it gets. At a forecourt, and truly only there, the petrol is still limited to your tank — since everywhere else your car was driven to reach it. The task is draining and cleaning on the spot.
Ignition on, or started for a second. The system has been primed, and so petrol has left that tank and got to the fuel filter and your lines. That is generally still a simple task — a drain, a flush, and the fuel filter seen to.
Those few miles on the road were the pump labouring on fuel thinned by petrol throughout. Tank, lines, filter, then fresh fuel run through the entire system: that's this work, and the way the car was driven matters as much as the mileage. Driving the children to Richard Hill Church of England Primary School is one sort of trip. Any mileage on the M1, under 5 miles from Thurcaston, means your engine working hard throughout, and a run to Leicester, under 5 miles away, makes a very different job too.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The fuel isn't acting like diesel any more, and the motor is saying so. Leave it where it has stopped: a lay-by, a side street, the verge on Leicester Road. A car pulled over early very rarely has permanent damage, since the drain and the flush-through, which still come first, deal with it.
What Thurcaston people get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. A diesel fuel system doesn't accept petrol by percentage in the way that guidance supposes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Protection counts more on modern diesels, not less, since their fuel passes through finer parts at higher pressure.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Any petrol motor fed diesel usually won't run, and so the driver stops and the harm stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, meant for another fault. None of what petrol diluted gets put back by it — and later, the tank still holds that petrol.
If the motor has run, part of that petrol sits in your filter and the lines, not your tank — and your next start sends it straight back through the pump. So the myth "drain that tank yourself and you're sorted" doesn't hold. Draining petrol into a can by the roadside is also genuinely risky.
How does petrol in a diesel take place?
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol car at all. So the mistake runs one way.
It occurs when habit and the car stop matching. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. A forecourt you know, only with its pumps laid out differently. A train to catch, and a rushed fill en route to Syston. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Skoda Octavia for the first time. Throw in rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up in Thurcaston
- The label is what counts, so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- The first fill in an unfamiliar car is the time to check your filler flap — on it, or on the cap, many motors state which fuel they take.
- Label your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It seems daft and it works.
- Mistakes like this are straightforward to make whilst your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to block a petrol nozzle, and aftermarket devices exist for the rest. Count it as a safety net, then keep reading the pump.
- Spotting it mid-fill? Stop there and then. A thinner mixture results from less petrol in the tank, yet your next step remains the same: don't fire it up.
Petrol already in a diesel in Thurcaston? Begin here
The order of things is short, then. Starting it is out, and so is switching on your ignition. The staff on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it clear of the pump if you ask. What got in, roughly how much, and if it has run: tell us those when you ring 0333 366 0103.
If it was AdBlue and not petrol, say so. That's a separate issue — corrosion and deposits instead of lost lubrication — and it has its own page for Thurcaston.
Thurcaston petrol in a diesel tasks: why one costs more than another
Four separate jobs lie behind the four situations above — which is why there is no honest single quote. The situation itself does most of the work of moving the cost. Two things follow that: the petrol that got in as a proportion of what the tank takes, then the spot the car is in and whether a van can reach it safely.
Before any quote, not after, we ask three questions: the fuel that went in, its volume, and if it's run. That's why. Those replies are what turn a range into one firm number.
About Thurcaston
Thurcaston is a village in Leicestershire, situated on the riverside at an elevation of 66 metres, with detached housing being the predominant type of accommodation. Thurcaston lies close to the city of Leicester, approximately 4.2 miles away, and is near other villages such as Cropston and Rothley. Thurcaston has a population of around 867 residents and is located near Rothley Plain. Thurcaston is positioned in the East Midlands region, about 92.8 miles from London.
Fuel drain cover in Thurcaston and across Leicestershire
Cropston, Rothley and Rothley Plain are among the places around Thurcaston that the same vans work, answering petrol in diesel call-outs across Thurcaston's LE postcode area. No need to move your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places where we work.
Still at the petrol pump around Thurcaston?
Then you're in the best place there is. Turned off it remains; then phone.