How Worried Should You Be? Petrol in a Diesel Car in Berthengam
Far less than you probably are, provided it hasn't been started. Until the ignition primes the pump, your starter cranks, or your vehicle is driven, petrol in a diesel tank just sits there and does no harm. Which means the truthful reply to the first Berthengam query — "have I ruined it?" — usually no. Leave the motor off and ring Petrol in Diesel — that keeps it like that. What petrol actually does to a diesel, how to gauge how far it's gone, and how to keep it from happening a second time: that's the remainder of this page.
What petrol in a diesel does to the engine
On its way through a motor, diesel does two jobs. It burns, and before it combusts it lubricates. Built to very fine gaps, the fuel injectors and the pump rely on your diesel flowing through them to stop their surfaces wearing against one another.
The second job petrol doesn't do at all, and the first it does poorly. It's runnier than diesel and strips away the protection your fuel system hinges on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
Taken together, they show the shape the problem takes. It is circulation that does the harm, not contact. A tank with petrol in it is a fuel problem. The beginning of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
Berthengam, petrol in a diesel: four cases, from mild to serious
Filled up, and never started: no case is better. Being at a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With that petrol kept in the tank alone, it's cleared and purged on the spot, and nothing more is needed.
Your ignition turned on, or a brief start. Once primed, your system has drawn petrol from the tank up to your filter and the lines. Normally little more than draining, flushing and seeing to your filter, so still straightforward.
Those few miles driven meant the pump working on fuel diluted by petrol throughout. The work is that tank, the lines, the filter and fresh fuel through the whole system, and how hard the car was driven counts as much as how far. Driving the kids to the local primary school is one kind of trip. Very different once more: a run to St Asaph, under 10 miles away, or some distance on the Moreton Spur, under 15 miles from Berthengam, where your engine never stopped labouring hard.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you your fuel is no longer behaving like diesel. Stop wherever you are — the verge on Sarn Road, a lay-by, a side street — and leave it there. Permanent damage is very rare if a vehicle is stopped quickly, and the fuel drain and flush-through that still come first take care of it.
Berthengam motorists and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing comes out when you top up — that tank just holds more of the same blend. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise parts: that is how a newer diesel handles its fuel, so the protection counts more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the damage stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. A running engine doesn't mean fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, meant for another issue. What petrol has thinned stays thinned, and the petrol remains in your tank anyway.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in your filter and lines, waiting to go right back through the pump at the next start. It is also really risky to drain petrol into a can at the kerbside.
How petrol ends up: petrol in a diesel
It is rarely carelessness, and no one does it on purpose. The forecourt makes it simple: the petrol nozzle is the narrower 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 vehicle at all. So the slip runs one way.
It occurs when routine and your car stop matching. Any vehicle that's new to you — hired, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. Filling up in a hurry on the way to Prestatyn, with a train to catch. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel at your next fill-up in Berthengam
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of cars state the fuel there.
- One of each in the household? Mark your key to your diesel — a coloured fob, a sticker — since intending to remember isn't enough.
- Before the nozzle leaves the pump the first time you fill a hired or new car, say "diesel" aloud. Daft, yes, yet it works.
- Put the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices are available for motors without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- The moment you realise, stop: less petrol inside the tank means a weaker mix. What to do next doesn't change, though — still don't start the car.
Petrol already in a diesel around Berthengam? Begin here
Then, there is only a short order of things. Leave it unstarted, with the ignition switched off as well. Yet at the forecourt, at Texaco or anywhere else? Ask the attendants to help you roll the car clear of the pump. Then ring 0333 366 0103 and tell us what went in, roughly how much, and if it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different problem — Berthengam has a page all for it.
One petrol in a diesel task around Berthengam costs more than another. Why?
A fair single price does not exist here: four scenarios, four separate tasks. What moves your cost is mostly which of them you are in. After that it is the proportion — how much petrol was put in against how much your tank holds — and then where the car is and whether our van can get to it safely.
What got in, how much, and whether it's run — three queries our engineers ask before quoting, not after, for exactly that reason. With the answers, there is a straight figure rather than a range.
About Berthengam
Berthengam is a small village in Flintshire, situated on the north Welsh coast, with an elevation of 191 metres. Berthengam lies near the cities of St Asaph and Rhyl, and is close to the villages of Sarn, Trelogan, and Axton. Berthengam has a population of around 628 people, predominantly living in detached houses.
Across Flintshire and around Berthengam: fuel drain cover
The vans answering petrol in diesel call-outs around Berthengam, in the CH postcode area, equally work the locations near it, Sarn, Trelogan and Axton among them. You need not bring the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
At the petrol pump around Berthengam, still?
Then you are in the best position there is. Turned off it remains; then phone.