How Worried Should You Be? Petrol in a Diesel Car in Purbrook
Provided it has not been started, you can worry far less than you likely are. Until your ignition primes the pump, the starter turns, or the vehicle is driven, petrol in a diesel tank simply waits there and does no harm. Which means the honest reply to the first Purbrook question — "have I ruined it?" — normally no. Petrol in Diesel is who to call, with your motor kept off, so it remains that way. Below, this page sets out what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
The engine and petrol in a diesel: what goes on
On its way through an engine, diesel does two jobs. Before it combusts, it protects — then it combusts. Made to very fine clearances, your injectors and the pump rely on your diesel moving through them to keep their surfaces from wearing against one another.
The second job petrol doesn't do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, because petrol is thinner than diesel and strips out the protection the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any knocking starts.
Together, those leave the shape of the problem plain. Not contact but movement is what does the damage. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds goes on, carried by the fuel, into the injectors downstream, which is why a pump that has been working on that petrol is where a mechanical fault begins.
Purbrook, petrol in a diesel: four situations, from mild to significant
Fuelled up, never started. The best case there is. At a forecourt, and really only there, that petrol is still confined to that tank — because anywhere else your car was driven to reach it. The job is emptying and purging on the spot.
Started for a moment, or only your ignition on. With the system primed, the fuel lines and filter already hold petrol that has come from the tank. That's usually still a straightforward task — a drain, a flush, and the fuel filter seen to.
Some miles driven, and the pump has spent each of them working on weakened fuel. The work is the tank, the lines, the fuel filter and fresh fuel through the whole system, and how hard your car was driven counts as much as how far. On the school run to St Peter's Catholic Primary School, Waterlooville, the miles is small. Any distance on the A3(M), under a mile from Purbrook, means the engine has worked hard throughout, and a run to Portsmouth, under 10 miles away, makes a very different job as well.
Driven on until it protested — rattling, smoke, a lumpy idle, a soft throttle. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Pull up wherever you are — the verge on Stakes Road, a lay-by, a side street — and leave the vehicle where it is. Permanent damage is very unusual when a vehicle is pulled over soon, and the drain and flush-through that still go first deal with it.
Purbrook motorists and the petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing comes out when you top up — your tank simply carries more of the same blend. The idea behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Not so: a current diesel copes with a bit of petrol. If anything, the reverse. A modern diesel sends its fuel through more precise parts at higher pressure, which makes the protection matter more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up most people than any other. Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the damage. While your pump wears, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated workaround for a different issue. It doesn't put back what petrol has thinned, and that petrol is still inside the tank afterwards.
The next start sends petrol back round the pump from your lines and the filter, where some of it ends up once the engine has run. That's why a DIY tank drain doesn't sort it — a myth. Also, a can of petrol drained by the kerbside is genuinely dangerous.
How does petrol in a diesel occur?
Carelessness is rarely the cause, and no one means to do it. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly won't go into a petrol vehicle at all. So the mistake runs one way.
It takes place when routine and your car stop matching. Hire cars, courtesy cars, and vehicles that are new to you. Two motors on one driveway, one petrol, one diesel. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a rushed fill en route to Bedhampton. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it occurs. Your hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
Next time you fill up in Purbrook: avoiding petrol in a diesel
- A green handle for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Many vehicles state the fuel inside your filler flap or on the cap, and so check it on the first fill in any car you do not know.
- One of each in the house? Label your key to the diesel — a bright fob, a sticker — because meaning to remember isn't enough.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds daft. It does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, so the 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. Treat it as a backstop, and keep reading the petrol pump.
- Stop the moment you realise. Less petrol inside that tank makes a weaker blend. It doesn't change what to do next, which is still not to start it.
Put petrol in a diesel around Purbrook already?
Then the order of things is brief. Don't fire it up, and don't switch the ignition on. If you're still on the forecourt — Asda or anywhere else — ask the attendants to help you roll it clear of the petrol pump. What was put in, about how much, and whether it's run: tell us that when you call 0333 366 0103.
If it was AdBlue and not petrol, say so. That's a different fault — corrosion and deposits instead of lost lubrication — and it has its own page for Purbrook.
One petrol in a diesel task around Purbrook costs more than another. Why?
Four separate tasks lie behind the four situations above — which is why there is no fair single quote. The situation itself does most of the work of moving your cost. Next it is the proportion — how much petrol got in against how much your tank holds — and then where the vehicle is and whether a van can get to it safely.
Three queries come first, before quoting, rather than after — what got in, how much, has it run — and that is the reason. A range turns into a straight figure when the answers are in.
About Purbrook and where it is
Purbrook is a locality in Hampshire, situated near the coast and approximately 5 miles north of Portsmouth, with a mix of residential areas and some remaining open spaces. Purbrook has a population of around 2859 people and is characterized by predominantly detached housing. Purbrook is close to other nearby places such as Crookhorn, Stakes, and Farlington, and is about 59 miles southwest of London.
Across Hampshire and in Purbrook: fuel drain cover
Petrol in diesel call-outs around Purbrook — part of the PO postcode area — go to teams that also cover the locations about it, Crookhorn, Stakes and Farlington among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians drain, and your car doesn't need to come to us.
Still at the petrol pump in Purbrook?
In that case, you couldn't be in a better spot. Ring, and leave it switched off.