Seaton: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — as long as nobody has started it. Everyone around Seaton starts with "have I wrecked it?", and the fair answer is normally no: petrol left in the tank of any diesel remains harmless until priming, cranking or driving pulls it into the system. Leave the motor off and ring Petrol in Diesel — that keeps it that way. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and ways to make sure you don't do it again.
Your engine and petrol in a diesel: what goes on
Two jobs fall to diesel on its route through a motor. It lubricates to begin with, and only then does it burn. The high-pressure fuel pump and your injectors are built to very fine tolerances, and the diesel passing through them is what keeps those surfaces from wearing down against one another.
Of these two tasks, petrol handles the first poorly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on that mixture wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you get the rattling.
Put these together and the shape of the trouble is plain. The harm is done by movement, not by contact. Where that petrol is only in that tank, it is a problem of fuel, nothing more. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the injectors downstream.
Petrol in a diesel in Seaton: how bad is it? Four situations
Filled but never started — the best it gets. Just the tank has petrol in it, so the job is draining the tank and purging your system where the car stands. This situation can only truly happen on a forecourt: anywhere else, the vehicle got there by being driven.
A brief spell of running, or just the ignition on. Petrol has left your tank and reached the filter and the lines, because the fuel system has been bled. Still normally straightforward: drain, flush, and your filter seen to.
Those few miles on the road meant your pump working on fuel weakened by petrol throughout. How hard the car was driven matters as much as how far, and this work takes in the tank, the lines, the fuel filter and clean fuel through the entire circuit. On the school run to the local primary school, the distance is small. A run as far as Aberdeen, under 3 miles away, is a very different job. So is any distance on the M90, over 50 miles from Seaton, where the motor has been working hard the whole time.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the engine reporting fuel that no longer runs like diesel. Pull up where you are — on the verge on School Drive, at the kerb, down a side road — and do not move it again. A car pulled over early very rarely has long-term damage, as the fuel drain and the flush-through, which still go first, deal with it.
Myths Seaton drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed when you top up — the tank simply holds more of the same blend. The idea behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. At higher pressure, through more precise parts: that's how a newer diesel handles its fuel, so the lubrication counts more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel usually has no choice but to stop, since it will not run, and the damage stops there. A diesel fed petrol normally starts, idles and drives away as though nothing has happened, while the pump grinds. A running engine doesn't mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a distinct fault. That petrol is still inside that tank afterwards, and whatever it has thinned isn't put back.
If the engine has run, part of that petrol is in your filter and the lines, not that tank — and the next start sends it straight back through the pump. So the myth "drain the tank yourself and you're sorted" doesn't hold. Clearing petrol into a can at the roadside is also genuinely hazardous.
How does petrol in a diesel occur?
Carelessness is rarely the cause, and no one means to do it. A diesel nozzle mostly won't go into a petrol motor, yet the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error straightforward, and only in that direction.
It happens when habit and the car stop matching. Any vehicle that is new to you — hired, on loan as a courtesy car, or brand new. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps arranged differently. Rushing for a train at Aberdeen and filling up en route. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you at the forecourt for its first tank — that is when. Throw in a back seat full of children, a phone call or rain, and habit takes over.
Next time you fill up around Seaton: avoiding petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what matters.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles state the fuel there.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a home has one of each. So mark it.
- Before the nozzle comes off the petrol pump the first time you fill a hired or new vehicle, say "diesel" aloud. Silly, perhaps, yet it works.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels have a filler built to reject a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Less petrol makes a weaker blend, so stop the moment you notice — while remembering that the next step is unchanged. It's still not to fire it up.
Petrol already in a diesel in Seaton? Start here
Then, there's just a short order of things. Don't crank it, and do not turn your ignition on. The attendants at the forecourt — whether at BP itself or wherever you filled up — will normally help roll it clear of the petrol pump if you ask. Next, 0333 366 0103. We'll ask what went in, about how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Seaton has a page just for it.
Seaton petrol in a diesel jobs: why one costs more than another
There's no honest single price for this, because the four scenarios above are four different jobs. The situation itself does most of the work of moving your cost. Two things come after that: the petrol that was put in as a share of what the tank holds, then the spot the car is in and whether our van can reach it safely.
That's why we ask three questions before pricing instead of after: what was put in, how much, and if it's run. Those answers change a range into a straight figure.
About Seaton and where it is
Seaton is a coastal suburban area in Aberdeen City, situated approximately 1.2 miles from Aberdeen city centre. Seaton sits at a low elevation of around 13 metres, with its predominant housing stock consisting of flats. Seaton is close to nearby places such as Old Aberdeen, Tillydrone, and Kittybrewster, and is home to a population of around 5732 people.
Fuel drain cover across Aberdeen City, Seaton included
Petrol in diesel jobs in Seaton — part of the AB postcode area — go to vans that also cover the spots round it, Old Aberdeen, Tillydrone and Kittybrewster among them. The car does not need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump in Seaton?
In that case, you could not be in a better spot. Ring, and leave it switched off.