High Dubmire: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, worry far less than you likely are. "Have I wrecked it?" is the first question anyone around High Dubmire asks, and the truthful answer is normally no, since petrol resting in a diesel tank hurts nothing until it is drawn through the system — by ignition priming, by the starter, or by driving. Petrol in Diesel is who to ring, with your motor left off, and so it remains that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and the way to make sure you never do it again.
Inside the motor: what petrol in a diesel does
On its way through a motor, diesel does two tasks. It protects to begin with, and after that does it burn. Designed to extremely fine tolerances, your injectors and the pump depend on the diesel flowing through them to stop their surfaces wearing against one another.
The second task petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump running on that mixture wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Together, those leave the shape of the trouble clear. Contact does not do the damage — movement does. Petrol in the tank is a fuel issue. The start of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream.
How bad is petrol in a diesel? Four scenarios we see in High Dubmire
Fuelled but not once started — as good as it gets. Only that tank has petrol in it, so the job is draining your tank and cleaning the system where the car sits. This situation can only truly happen on a forecourt: anywhere else, your car got there by being driven.
Your ignition turned on, or a short start. The fuel system has been primed, and so petrol has left the tank and got to your filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually simple.
Those few miles driven meant your pump labouring on fuel diluted by petrol the whole way. The work is that tank, the fuel lines, the fuel filter and clean fuel through the whole circuit, and how hard your car was driven matters as much as how far. Driving the children to Dubmire Primary is one kind of trip. Any mileage on the A1(M), under 3 miles from High Dubmire, means your engine has worked hard throughout, and a run to Sunderland, under 10 miles away, makes a very different task too.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. That is your engine telling you its fuel no longer is acting like diesel. Stop where you are — on the verge on Flixton, at the kerb, down a side road — and don't move it. What comes first is still the fuel drain and flush-through, and that deals with it, with long-term damage very unusual if a vehicle is stopped quickly.
What High Dubmire people get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. Nothing comes out when you top up — your tank just holds more of the same mixture. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Finer parts and higher pressure are the way a newer diesel runs its fuel, and that makes the lubrication matter more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more people than any other. Any petrol engine fed diesel normally won't run, so the driver stops and the damage stops with them. Whilst your pump grinds, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, meant for another fault. It doesn't put back what petrol has diluted, and that petrol is still inside the tank later.
The next start draws petrol back round your pump from the lines and the filter, where some of that ends up once the motor has run. That's why a DIY tank drain does not leave you sorted — a myth. It is also genuinely hazardous to drain petrol into a can by the roadside.
Why petrol in a diesel happens so easily
It is rarely carelessness, and no one does it on purpose. A diesel nozzle generally won't go into a petrol vehicle, but the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and only in one direction.
Routine and the vehicle falling out of step is how it happens. Hire cars, courtesy cars, and motors that are new to you. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A train to catch, and a hurried fill en route to Chester-Le-Street. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it takes place. Add rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
Next time you fill up in High Dubmire: preventing petrol in a diesel
- The label is what matters, and so check the petrol pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- Plenty of motors state the fuel inside your filler flap or on the cap, and so check it on the first fill in a motor you do not know.
- Mark the key. In a house 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" out loud before you lift the nozzle off the pump. It seems silly and it works.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the pump.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that will not take a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Less petrol means a thinner mixture, and so stop as soon as you notice — while remembering that the next stage is unchanged. It is still not to start the car.
High Dubmire: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off too. If you're still at the forecourt — Esso or anywhere else — ask the attendants to help you roll it away from the petrol pump. Next, 0333 366 0103. We will ask what went in, roughly how much, and if it has been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate problem — High Dubmire has a page just for it.
What makes one High Dubmire petrol in a diesel job cost more than the next
There is no honest single quote for this, because the four scenarios above are four separate tasks. Mostly, the cost moves with which situation you are in. The proportion counts next, meaning how much of your tank is petrol, and then the position of the car and whether getting to it is safe for our van.
What went in, how much, and if it has run — three questions our technicians ask before pricing, not after, for exactly that reason. Those answers change a range into a straight figure.
About High Dubmire, briefly
High Dubmire is a village situated on the riverside in Tyne and Wear, with a population of around 2070 people. High Dubmire has a mix of housing types, but is predominantly characterised by terraced homes. High Dubmire sits at an elevation of 49 metres, close to the nearby cities and towns of the North East region, including Sunderland which is approximately 5.9 miles away. High Dubmire is also near other local places such as Fence Houses, Chilton Moor, and Colliery Row.
Fuel drain cover across Tyne and Wear, High Dubmire included
High Dubmire sits in the DH postcode area, and the teams that answer petrol in diesel call-outs there work the spots near it as well — Fence Houses, Chilton Moor and Colliery Row among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our engineers drain, and your car doesn't need to move to us.
High Dubmire: still at the petrol pump?
The best position there is, then — that is where you are. Keep it switched off, and ring.