Should You Worry? Petrol in a Diesel Car in Coundon
If it has not been started, you can worry less than you probably are. Until your ignition primes your pump, the starter cranks, or the car is driven, petrol in a diesel tank just sits there and does no harm. Which makes the honest reply to the first Coundon question — "have I ruined it?" — usually no. Keep it like that: leave the motor off and call Petrol in Diesel. The rest of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
Petrol in a diesel: what does it do to the motor?
Diesel has two tasks on its way through a motor. Before it ignites, it lubricates — then it ignites. Built to extremely fine tolerances, the injectors and your pump rely on your diesel moving through them to stop their surfaces wearing against one another.
Of these two jobs, petrol manages the first poorly and the second not at all. The clattering comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the fuel system depends on, and any pump working on that blend is wearing itself.
Seen together, they show what shape the issue has. Not contact but movement is what causes the harm. Any tank with petrol in it is a fuel problem. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
Four scenarios our engineers see in Coundon: how bad is petrol in a diesel?
Fuelled, and never started: no case is better. At a forecourt, and genuinely only there, the petrol is still confined to the tank — because anywhere else the car was driven to get to it. The job is emptying and purging on the spot.
A moment's running, or merely the ignition on. With the system primed, your lines and filter now contain petrol that has come from that tank. Drain, flush, deal with your filter: still normally easy.
Driven a couple of miles. Now the pump has spent these miles running on weakened fuel. The work is the tank, your lines, your filter and clean fuel through the entire system, and how hard the car was driven counts as much as how far. Driving the kids to St Joseph's Catholic Primary School, Coundon is one kind of trip. Any mileage on the A1(M), under 5 miles from Coundon, means the engine working hard throughout, and a run to Durham, under 10 miles away, makes a very different task too.
Knocking, an uneven idle, smoke, a throttle gone soft: driven till it complained. The fuel isn't acting like diesel any more, and your engine is telling you. Whether it's the verge on Collingwood Street, a lay-by or a side road, stop there then leave it. A car pulled over early very seldom has lasting damage, since the drain and the flush-through, which still come first, sort it out.
Stories Coundon people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — that tank just holds more of the same blend. A diesel fuel system doesn't accept petrol by percentage in the way that guidance assumes.
Not so: a current diesel copes with a bit of petrol. Rather, the reverse. At higher pressure, through finer parts: that's how a current diesel handles its fuel, so the lubrication matters more, not less.
The myth that catches motorists out: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that won't run: the driver stops, and so does the harm. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump wears. Running doesn't mean fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old workaround, supposed for another issue. What petrol has diluted stays thinned, and that petrol remains inside your tank regardless.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol sits in your filter and lines, waiting to go straight back through the pump on your next start. On top of that, petrol emptied into a can by the road is genuinely dangerous.
Petrol in a diesel: how does it occur?
A careless moment is seldom the cause, and no one means to do it. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol car at all. So the slip runs one way.
It happens when routine and the vehicle stop matching. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. A hurried fill on the way to Bishop Auckland with a train to catch. The first fill-up in a diesel Renault Clio after years of driving petrol is exactly the moment it takes place. Add a back seat full of kids, a phone call or rain, and habit wins.
How to avoid petrol in a diesel on your next fill-up around Coundon
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is only a clue.
- Many cars state the fuel inside your filler flap or on the cap, and so check there on your first fill in any motor you don't know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, in a house with one of each.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" out loud. Daft, yes, yet it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck your phone away and keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed 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 checking the pump.
- Noticing it mid-fill? Stop there and then. A weaker mixture results from less petrol inside your tank, yet your next stage remains the same: don't start it.
Coundon: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with your ignition off as well. Ask the staff to help you push it away from the petrol pump if you are still at the forecourt, whether that's Gulf or somewhere else. Ring 0333 366 0103 next, with three facts — your fuel, the approximate amount, and if it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate fault — Coundon has a page all for it.
Coundon petrol in a diesel tasks: why one costs more than another
The four situations above are four different tasks, so no single price for this would be fair. Which of them you are in is mostly what moves the cost. The share counts next, meaning how much of the tank is petrol, and then the location of the vehicle and whether getting to it is safe for our van.
Ahead of any quote, not after, we ask three questions: your fuel that was put in, the amount, and whether it has run. That is why. Those replies change a range into a straight figure.
About Coundon itself
Coundon is a small village in County Durham, situated inland at an elevation of 173 metres, approximately 8 miles from the city of Durham. Coundon has a population of around 2001 residents, living primarily in terraced housing. Coundon is close to nearby settlements such as Leeholme and New Coundon, and is located in the north east of England, some 226 miles north of London.
Fuel drain cover across Durham, Coundon included
Coundon sits in the DL postcode area, and our vans that answer petrol in diesel calls there work the locations around it as well — Leeholme, Howlish and New Coundon among them. The vehicle doesn't 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 around Coundon?
In that case, you couldn't be in a better place. Keep it off. Phone.