Bryniau: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you likely are. Petrol resting in a diesel tank does nothing to the engine until something pulls it through your fuel system — the ignition priming your pump, the starter, or driving on its own. So the truthful answer to the first query anyone around Bryniau asks, "have I ruined it?", is normally no. To keep the vehicle like that, phone Petrol in Diesel and leave the motor alone. Below, you will find what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you again.
What petrol in a diesel does to the motor
Two tasks fall to diesel on its journey round a motor. It protects first, and after that does it burn. Very fine tolerances are built into your injectors and your high-pressure pump, and only the diesel running through keeps their surfaces from grinding together.
Petrol does the first job poorly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump on the blend wearing itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the rattling.
Combined, those make the shape of the problem clear. Contact does not do the damage — circulation does. Petrol in a tank is a fuel problem. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Petrol in a diesel in Bryniau: how bad is it? Four cases
Fuelled up, never started. The best case there can be. Only your tank has petrol in it, and so the job is emptying that tank and cleaning the fuel system where your car sits. This scenario can only really occur at a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a second. Petrol has come out of the tank and reached the filter and the lines, since the system has been bled. Normally little more than emptying, rinsing and seeing to the fuel filter, so still simple.
Some miles driven, and the pump has spent each of them labouring on diluted fuel. The work is the tank, the fuel lines, the filter and clean fuel through the whole circuit, and how hard your car was driven counts as much as how far. On the school run to the local primary school, the mileage is small. A run as far as St Asaph, under 5 miles away, is a very different job. So is any distance on the Moreton Spur, under 15 miles from Bryniau, where the motor has been working hard throughout.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. The engine is telling you your fuel is no longer behaving like diesel. Whether it's the verge on Ffordd Bryniau, a lay-by or a side road, stop where you are then leave it. A vehicle stopped soon very seldom has permanent damage, as the drain and the flush-through, which still come first, sort it out.
Stories Bryniau drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed when you top up — that tank simply carries more of the same blend. The assumption behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Finer components and higher pressure are the way a newer diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools people. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor normally means a motor that won't run: the driver stops, and so does the harm. Feed petrol to a diesel and it generally starts, idles and drives away as if nothing happened — all while its pump is wearing. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old fix for a separate fault. That petrol is still in your tank after that, and what it has diluted isn't put back.
The next start draws petrol back round your pump out of your lines and your filter, where some of that ends up after the engine has run. That's why a DIY tank drain doesn't leave you sorted — a myth. It's also really dangerous to drain petrol into a can at the roadside.
How petrol ends up: petrol in a diesel
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
When routine and your car stop matching, it occurs. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill on the way to Prestatyn. A new-to-you diesel Renault Clio, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Bryniau people: how to prevent petrol in a diesel next time
- The label is what matters, so read the petrol pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Plenty of cars state the fuel type inside your filler flap or on the cap, so check it on your first fill in a car you do not know.
- Label your 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 meaning to remember.
- Before the nozzle leaves the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Silly, yes, but it works.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away and keep your mind on the petrol pump.
- Add-on devices are available for cars without one, and some diesels come with a filler that won't accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol inside the tank makes a thinner mix. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel around Bryniau already?
Then the order of things is brief. Starting it is out, and so is switching on the ignition. Ask the staff to help you roll it away from the petrol pump if you are still at the forecourt, whether that is Tesco or anywhere else. Next, 0333 366 0103. We'll ask what went in, about how much, and if it's been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different issue — Bryniau has a page just for it.
One petrol in a diesel job in Bryniau costs more than another. Why?
Four separate jobs sit 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. The ratio counts next, meaning how much of your tank is petrol, followed by the location of your car and whether reaching it is safe for a van.
Ahead of any quote, not after, come three queries: your fuel that was put in, the quantity, and whether it has run. That's why. A range turns into a straight figure once the replies are in.
About Bryniau
Bryniau is a suburban area in Denbighshire, situated on the north Welsh coast, with an elevation of 119 metres. Bryniau lies near the city of St Asaph, approximately 4 miles away, and is close to other nearby places such as Tan-yr-allt, Meliden, and Gwaenysgor. Bryniau has a population of around 1668 people, predominantly living in semi-detached housing.
Fuel drain cover in Bryniau and across Denbighshire
Petrol in diesel jobs around Bryniau — part of the LL postcode area — go to teams that likewise cover the spots round it, Tan-yr-allt, Meliden and Gwaenysgor included. You need not bring the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places where we work.
At the pump around Bryniau, still?
In that case, you couldn't be in a better spot. Phone, and leave it turned off.