Alsager: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, provided it has not been started. "Have I ruined it?" is the first thing everyone in Alsager asks, and the truthful answer is generally no, since petrol left in a diesel tank harms nothing till it's dragged through the system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to phone, with the motor left off, so it stays that way. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has spread, and the way to make sure you don't do it again.
Petrol in a diesel: what does it do to the motor?
Diesel has two tasks on its way through a motor. Before it combusts, it lubricates — and then it burns. Extremely fine clearances are built into the fuel injectors and your high-pressure pump, and just your diesel running through stops those surfaces grinding together.
The second job petrol doesn't do at all, and the first it does poorly. The knocking comes from petrol being designed not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication the system rests on, and any pump running on that mix is wearing itself.
Seen together, they show the shape the trouble takes. It's circulation that causes the damage, not contact. Petrol in a tank is a fuel problem. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to your injectors beyond it.
Petrol in a diesel in Alsager: how serious is it? Four situations
The best case there is: filled up, not once started. That petrol is in the tank and just that tank, and the task is a drain and a flush where the vehicle stands. This is the one situation that can only truly occur on a forecourt, because anywhere else the car has been driven to get there.
A brief spell of running, or just the ignition on. The fuel system has been bled, and so petrol has left your tank and reached your filter and your lines. Drain, flush, see to the fuel filter: still usually straightforward.
Your pump has spent a few miles on diluted fuel — that is what driving the car does. The work is your tank, your lines, the fuel filter and clean fuel through the whole system, and how hard your car was driven counts as much as how far. The school run to Alsager Highfields Community Primary School is one matter. Very different again: a run to Stoke-on-Trent, under 10 miles away, or any mileage on the M6, under 3 miles from Alsager, where the motor kept working hard.
Driven on till it complained — rattling, smoke, a lumpy idle, a dead throttle. What you are hearing is the motor reporting fuel that no longer acts like diesel. Whether it's the verge on Sandbach Road South, a lay-by or a side street, stop there and leave it. A car stopped soon very rarely has permanent damage, because the fuel drain and the flush-through, which still come first, take care of it.
Alsager drivers and the petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A bigger tank of the same mixture is all you get, because topping up removes nothing. The idea behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
"Newer diesels can handle a little petrol" — a myth, and nearer the opposite. Smaller parts and higher pressure are the way a current diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." The motorist of a petrol motor fed diesel normally stops, since it will not run, and the harm stops with them. Feed petrol to a diesel and it normally starts, idles and drives away like nothing happened — all the while its pump wears. Running is not the same as fine.
Not so: a two-stroke additive lets you to drive home. It was an old fix, supposed for another fault. None of what petrol weakened gets put back by it — and later, your tank still holds the petrol.
The next start draws petrol back round your pump from the fuel lines and the filter, where some of it sits after the motor has run. That's why draining the tank yourself doesn't leave you sorted — a myth. On top of that, petrol cleared into a can by the road is truly hazardous.
How it happens: petrol in a diesel
Nobody does it on purpose, and it is rarely carelessness. A diesel nozzle generally will not go into a petrol car, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and only in one direction.
The moment routine stops matching the vehicle is the moment it occurs. A new motor, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill on the way to the nearest station. Years of petrol cars behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that's when. Add a back seat full of kids, a phone call or rain, and the hand takes over.
Next time you fill up around Alsager: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of vehicles state the fuel there.
- Label the key. In a household 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 your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so put your phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop reading the pump.
- Stop the moment you realise. Less petrol in your tank makes a thinner mixture. It does not change what to do next, which is still not to start the car.
Put petrol in a diesel in Alsager already?
Then the order of things is brief. Leave it unstarted, with your ignition switched off as well. Yet on the forecourt, at Lawton Service Station or anywhere else? Ask the attendants to help you push it clear of the petrol pump. What went in, about how much, and whether it has run: tell us those when you call 0333 366 0103.
If it was AdBlue instead of petrol, say so. That's a separate fault — corrosion and deposits instead of lost lubrication — and it has its own page for Alsager.
Alsager petrol in a diesel jobs: why one costs more than another
Four separate jobs lie behind the four situations above — which is why there's no fair single quote. Which of them you are in is mostly what moves the cost. Two things follow that: the petrol that got in as a share of what the tank takes, then the spot the vehicle is in and whether a technician can get to it safely.
Ahead of any quote, not after, we ask three questions: the fuel that was put in, its quantity, and if it has run. That's why. Those replies are what change a range into one firm number.
About Alsager and its setting
Alsager is a town in eastern Cheshire, situated inland at an elevation of around 95 metres, approximately 7.5 miles southwest of Stoke-on-Trent. Alsager has a population of around 11679 people, with a predominance of detached housing. Alsager is close to nearby places such as Lawton Heath, Lawton Heath End, and Lawton-gate, and is about 143.2 miles northwest of London.
Fuel drain cover around Alsager and across Cheshire
Alsager sits in the ST postcode area, and the teams that answer petrol in diesel call-outs there work the locations around it as well — Lawton Heath, Lawton Heath End and Lawton-gate among them. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Still at the petrol pump in Alsager?
Then you are in the best spot there is. Keep it off. Call.