Should You Worry? Petrol in a Diesel Car in Whitland
Not started? Then less anxious than you probably are. Petrol sitting in a diesel tank does nothing to the engine till something draws it through your fuel system — the ignition priming your pump, the starter, or driving itself. So the truthful answer to the first question anyone around Whitland asks, "have I wrecked it?", is usually no. Petrol in Diesel is who to call, with your motor kept off, so it stays that way. The rest of this page explains what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
What petrol in a diesel does to the engine
Two jobs fall to diesel on its journey through a motor. Lubricating comes before burning; it does both. Very fine clearances go into the injectors and your high-pressure pump, and only your diesel flowing through keeps their surfaces from grinding together.
Poorly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump on the blend to wear itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the rattling.
The shape of the issue is clear once you put those together. Contact does not do the harm — movement does. All a tank with petrol in it amounts to is a fuel issue. A pump that has been working 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.
How serious is petrol in a diesel? Four situations our engineers see in Whitland
Filled but never started — as good as it gets. The petrol is inside that tank and just that tank, and the job is a drain and a flush where the vehicle stands. This is the one situation that can only really take place on a forecourt, as anywhere else your car has been driven to get there.
Your ignition turned on, or a short start. Petrol has left that tank and got to the filter and your lines, because the system has been primed. That's generally still a simple task — a drain, a flush, and the filter seen to.
The pump now spent a couple of miles on weakened fuel — that is what driving the car meant. The work is that tank, your lines, the fuel filter and fresh fuel through the whole system, and how hard the car was driven counts as much as how far. A school run to the local primary school is one thing. Driving as far as St Davids, under 50 miles away, makes a very different job — as does any distance on the M4, under 25 miles from Whitland, with your engine labouring hard all the way.
Driven until it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer acting like diesel. Whether it is the verge on Market Street, a lay-by or a side street, stop where you are and leave it. Permanent damage is very uncommon when a car is pulled over early, and the drain and flush-through that still come first deal with it.
Whitland motorists and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. A bigger tank of the same mixture is all you get, because topping up removes nothing. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through more precise components: that's how a newer diesel moves its fuel, and so the protection counts more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there is no harm done." Any petrol engine fed diesel generally won't run, and so the driver stops and the harm stops with them. Feed petrol to a diesel and it generally fires up, ticks over and drives away like nothing has happened — all the while its pump is wearing. Running is not the same as fine.
An old workaround for a distinct issue is behind this one. Myth: "Add some two-stroke oil and drive the car home." It doesn't put back what petrol has thinned, and the petrol is still in your tank after that.
If the engine has been run, part of the petrol sits in the filter and the fuel lines, not your tank — and the next start sends it straight back through the pump. So the myth "drain the tank yourself and you are sorted" does not stand up. Besides, petrol emptied into a can by the road is genuinely dangerous.
How does petrol in a diesel occur?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the slimmer 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 motor at all. So the slip runs one way.
It takes place when routine and your car stop matching. A vehicle that's new to you — hired, on loan as a courtesy car, or brand new. Two motors on one driveway, one petrol, one diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill en route to the nearest station. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: precisely when it occurs. Add rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up in Whitland: avoiding petrol in a diesel
- 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 counts.
- The first fill in a strange car is the time to check your filler flap — on it, or on the cap, plenty of cars state which fuel to use.
- One of each in the house? Mark the key to your diesel — a bright fob, a sticker — since meaning to remember is not enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds silly. It works.
- Whilst you're thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices exist for cars without one, and some diesels are built with a filler that won't take a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Spotting it mid-fill? Stop there and then. A weaker mixture results from less petrol in your tank, but the next step remains the same: don't crank it.
Petrol already in a diesel around Whitland? Start here
Then the order of things is short. Don't start it, and don't turn the ignition on. Still at the forecourt, at Preseli Filling Station or anywhere else? Ask the staff to help you roll the car clear of the pump. Then phone 0333 366 0103 and tell us what was put in, roughly how much, and whether it's run.
Corrosion and deposits are the trouble with AdBlue, whereas petrol means lost protection. So if it was AdBlue, say so — and read its own Whitland page.
What makes one Whitland petrol in a diesel task cost more than the next
An honest single quote doesn't exist here: four situations, four separate tasks. The situation itself does most of the work of moving your cost. Two things follow that: the petrol that went in as a share of what your tank holds, then the place your car is in and whether a technician can reach it safely.
Before any quote, not after, come three queries: the fuel that was put in, the amount, and whether it has run. That is why. A range turns into a straight figure once those replies are in.
About Whitland, briefly
Whitland is a small town in Carmarthenshire, situated on the River Taf, with a mix of detached housing and local amenities. Whitland sits at a low elevation of 19 metres, near the villages of Trevaughan and Llwyn-y-brain. Whitland is located close to the High Street and is surrounded by the Welsh countryside, with St Davids city approximately 28 miles away. Whitland has a population of around 1907 people, living in a range of detached homes.
Whitland and Carmarthenshire: where our fuel drain cover reaches
Whitland rests in the SA postcode area, and the vans that answer petrol in diesel call-outs there work the places around it as well — Trevaughan, Llwyn-y-brain and High Street among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians work, and the car doesn't need to come to us.
At the petrol pump in Whitland, right now?
Then, you couldn't be in a better spot. Keep it off. Ring.