Petrol in a Diesel Car in Hulham: How Worried Should You Be?
Probably less than you are now — as long as no one has started the vehicle. Petrol sitting in a diesel tank does nothing to the motor until something draws it through the fuel system — the ignition priming your pump, the starter, or driving itself. So the honest answer to the first question anyone around Hulham asks, "have I ruined it?", is normally no. To leave the car like that, phone Petrol in Diesel and leave your engine switched off. Further down, you will find what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
What petrol in a diesel does to your engine
Passing through a motor, diesel does two jobs at the same time. Before it combusts, it lubricates — then it burns. What keeps the surfaces inside the high-pressure fuel pump and your injectors from wearing down against one another is your diesel flowing through them — they're made to very fine clearances.
The second job petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump on the blend wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
Combined, those leave the shape of the issue plain. Contact does not do the damage — circulation does. A tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has been working on the petrol is where a mechanical fault starts.
How serious is petrol in a diesel? Four situations our technicians see around Hulham
Fuelled but never started — the best it gets. That petrol is inside the tank and only that tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only really take place on a forecourt, since anywhere else your car has been driven to get there.
A brief spell of running, or merely the ignition on. Petrol has come out of your tank and got to the filter and your lines, because the system has been bled. Drain, flush, see to the filter: still normally easy.
Those few miles driven were the pump labouring on fuel diluted by petrol the whole way. Miles is only half of it; how hard it was driven counts just as much. Either way the work runs to that tank, the fuel lines, your filter and clean fuel through the whole circuit. Driving the children to Brixington Primary Academy is one kind of trip. A run as far as Exeter, under 10 miles away, is a very different task. So is any mileage on the M5, under 5 miles from Hulham, where the motor has been running hard throughout.
Clattering, an uneven idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the motor reporting fuel that no longer runs like diesel. Stop wherever you are — the verge on Booth Way, a lay-by, a side street — and leave it where it is. What comes first is still the drain and flush, and that sorts it out, with long-term damage very uncommon if a car is stopped early.
Hulham drivers and that petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that guidance assumes.
Not so: a newer diesel copes with a bit of petrol. If anything, the reverse. Lubrication matters more on current diesels, not less, because their fuel runs through more precise parts at higher pressure.
"It starts, it drives, and so there is no harm" — the myth that trips up most motorists than any other. Any petrol engine fed diesel generally will not run, so the motorist stops and the harm stops with them. Whilst the pump wears, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Fine and running are not the same at all.
An outdated fix for a different issue is behind this one. Myth: "Add some two-stroke oil and drive it home." It does not put back what petrol has diluted, and the petrol is still inside that tank later.
The next start sends petrol back round your pump from the fuel lines and your filter, where some of that sits after the motor has been run. That's why draining your tank yourself does not leave you sorted — a myth. It is also genuinely dangerous to drain petrol into a can by the kerbside.
Petrol in a diesel: how does it happen?
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol vehicle at all. The forecourt makes it simple, and the error runs one way.
Routine and the vehicle falling out of step is when it happens. Hire cars, courtesy cars, and motors that are new to you. A household with one petrol and one diesel on the driveway. The pumps in a different order on a well-known forecourt. Racing for a train outside Exmouth and filling up en route. Years of petrol vehicles behind you, a diesel Volkswagen Passat in front of you on the forecourt for its first tank — that's when. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Avoiding petrol in a diesel next time you fill up around Hulham
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Check the petrol pump's label; the colour is just a hint.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of cars print the fuel type there.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key if a home has one of each. So label it.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It seems silly and it does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, so the phone goes away.
- Some diesels come with 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 petrol pump.
- Noticing it mid-fill? Stop there and then. A weaker blend follows from less petrol inside the tank, yet your next step remains the same: don't crank it.
Put petrol in a diesel in Hulham already?
In that case, there's only a short order of things. Leave it unstarted, with your ignition switched off too. If you're still on the forecourt — Tesco or anywhere else — ask the staff to help you push the vehicle away from the pump. Next, 0333 366 0103. We'll ask what was put in, roughly how much, and if it has been run.
Say so if it was AdBlue instead of petrol: it's a different issue, with its own page for Hulham, since AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel job around Hulham costs more than another
Four separate jobs sit behind the four situations above — which is why there is no honest single price. What shifts the cost is chiefly which of them you are in. Where your car is matters too, and whether a technician can safely get to it, after the proportion of petrol to what that tank holds.
That is why our engineers ask three questions before pricing instead of after: what was put in, how much, and whether it has run. Their answers are what turn a range into one firm number.
About Hulham and its setting
Hulham is a suburban area in Devon, situated near the coast and approximately 8 miles from Exeter. Hulham sits at an elevation of 52 metres, overlooking the surrounding landscape. Hulham is characterised by its predominantly detached housing stock, with nearby places including Brixington and Withycombe Raleigh.
Fuel drain cover around Hulham and across Devon
Petrol in diesel jobs around Hulham — part of the EX postcode area — go to teams that likewise cover the locations round it, Brixington, Withycombe Raleigh and Exmouth included. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots we drain.
Still at the petrol pump around Hulham?
Then, you couldn't be in a better position. Turned off it stays; then phone.