Shenley Fields: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — provided no one has started the vehicle. Everyone in Shenley Fields starts with "have I ruined it?", and the honest answer is generally no: petrol resting inside the tank of any diesel remains harmless until priming, cranking or driving pulls it into your fuel system. Keep it like that: leave your motor off and call Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it's gone, and how to stop it from happening again: that's the remainder of this page.
What petrol in a diesel does to the motor
Two tasks fall to diesel on its journey round a motor. Before it combusts, it protects — and then it burns. Designed to extremely fine gaps, the injectors and the pump depend on your diesel flowing through them to stop their surfaces wearing against one another.
The second job petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on the mixture to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the knocking.
The shape of the trouble is plain when you put those together. It's movement that does the harm, not contact. Where that petrol is only in the tank, it's a fault of fuel, nothing more. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream.
Four situations our engineers see in Shenley Fields: how serious is petrol in a diesel?
Fuelled, and never started: nothing beats it. Only that tank has petrol in it, and so the task is clearing your tank and cleaning your system where your car sits. This situation can only really happen at a forecourt: anywhere else, the car got there by being driven.
Started for a moment, or only the ignition on. Petrol has come out of the tank and reached the filter and your lines, because the fuel system has been primed. Normally little more than draining, flushing and seeing to your filter, so still easy.
Some miles driven, and the pump has spent every one of them labouring on weakened fuel. The work is the tank, the fuel lines, your filter and fresh fuel through the entire system, and how hard your car was driven counts as much as how far. Driving the children to Green Meadow Primary School is one sort of trip. Driving as far as Birmingham, under 5 miles away, makes a very different job — as does any miles on the Frankley Services Southbound, under 3 miles from Shenley Fields, with the engine working hard the whole time.
Driven until it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the engine signalling fuel that no longer acts like diesel. Leave it where it stops: a lay-by, a side street, the verge on Shenley Lane. A vehicle stopped quickly very rarely has long-term damage, as the fuel drain and the flush, which still come first, sort it out.
Shenley Fields people and that petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mixture is all it gives, since topping up removes nothing. That guidance assumes a diesel fuel system handles petrol by percentage. It does not.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. A newer diesel runs its fuel through smaller components at higher pressure, which makes the protection count more, not less.
This is the one that catches motorists. Myth: "If it starts and drives, there's no damage done." A petrol motor fed diesel usually won't run, and so the motorist stops and the damage stops with them. A diesel fed petrol generally starts, ticks over and drives away as though nothing has happened, while the pump wears. Running doesn't mean fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old workaround for a separate fault. What petrol has thinned remains thinned, and the petrol stays inside that tank regardless.
Myth: "Drain that tank yourself and you're sorted." After your engine has been run, some of that petrol is no longer in your tank: it is in the filter and your lines, and it goes right back through the pump at the next start. Besides, petrol cleared into a can by the road is truly hazardous.
Why petrol in a diesel happens so easily
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol car. That is how the forecourt makes it simple.
The moment routine stops matching the car is the moment it takes place. Courtesy car, hire car, or a motor that's new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps laid out differently. Filling up in a rush en route to Northfield, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it happens. Add rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
How to prevent petrol in a diesel on your next fill-up in Shenley Fields
- The label is what counts, so read the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of vehicles print the fuel type there.
- Mark the key. In a house with one of each, a coloured fob or a sticker on your 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 petrol pump. It sounds daft and it does the trick.
- Mistakes like this are simple to make while your mind is on something else, and so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and add-on devices exist for the remainder. Count it as a safety net, then keep reading the pump.
- Noticing it mid-fill? Stop there and then. A weaker mixture follows from less petrol inside your tank, but the next stage stays the same: do not start the car.
Put petrol in a diesel in Shenley Fields already?
Then, there is only a short order of things. Don't start the vehicle, and don't switch your ignition on. Yet at the forecourt, at Sainsbury's or anywhere else? Ask the staff to help you roll the car clear of the pump. What got in, roughly how much, and if it's run: tell us that when you phone 0333 366 0103.
Corrosion and deposits are the issue with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and read its own Shenley Fields page.
One petrol in a diesel job in Shenley Fields costs more than another. Why?
There's no honest single price for this, since the four scenarios above are four separate jobs. Which of them you are in is chiefly what shifts the cost. After that it's the ratio — how much petrol went in against how much the tank holds — and after that where the car is and whether a van can get to it safely.
That is why we ask three questions before pricing instead of after: what went in, how much, and if it has run. The replies turn a range into a straight figure.
About Shenley Fields, for a moment
Shenley Fields is a suburban area in the West Midlands, situated near the River Rea and close to the city of Birmingham. Shenley Fields has a mix of semi-detached housing and local amenities, with nearby green spaces such as Woodcock Hill. Shenley Fields is located at an elevation of 192 metres, and its residents are approximately 4.7 miles from Birmingham city centre. Shenley Fields is also within commuting distance of London, which is around 101 miles to the southeast.
Fuel drain cover across West Midlands, Shenley Fields included
Our vans answering petrol in diesel jobs in Shenley Fields, in the B postcode area, also work the spots around it, Woodcock Hill, Bartley Green and Weoley Castle included. No need to bring the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots we drain.
At the pump in Shenley Fields, still?
In that case, you could not be in a better position. Keep the vehicle turned off, then ring.