Should You Worry? Petrol in a Diesel Car in North Hillingdon
Far less than you likely are, if it has not been started. Until your ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank simply rests there and does no harm. Which means the honest reply to the first North Hillingdon question — "have I wrecked it?" — usually no. Keep it like that: leave your motor off then ring Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's gone, and how to keep it from happening again: that is the rest of this page.
Inside the engine: what petrol in a diesel does
Passing through a motor, diesel is doing two jobs at once. Before it combusts, it lubricates — then it combusts. Extremely fine clearances are built into the fuel injectors and your high-pressure pump, and only your diesel running through stops those surfaces grinding together.
The second job petrol doesn't do at all, and the first it does badly. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where the rattling comes.
Taken together, they show what shape the trouble takes. Not contact but circulation is what causes the damage. All a tank with petrol in it amounts to is a fuel fault. Once your pump has been running on that petrol, a mechanical issue has started: whatever is shed by a pump that is wearing down travels downstream to the injectors with your fuel.
Petrol in a diesel around North Hillingdon: how bad is it? Four cases
Filled up, not once started. The best case there can be. On a forecourt, and genuinely only there, that petrol is still confined to the tank — since anywhere else the vehicle was driven to reach it. The job is emptying and flushing on the spot.
Started for a second, or just the ignition on. The system has been primed, and so petrol has left that tank and reached the filter and the fuel lines. That is usually still a straightforward task — a drain, a flush, and the fuel filter seen to.
Driven a couple of miles. Now the pump has spent these miles working on diluted fuel. Tank, lines, filter, then clean fuel run through the whole circuit: that's the work, and the way the car was driven matters as much as the distance. Driving the children to Oak Farm Primary School is one kind of trip. A run as far as Westminster, under 15 miles away, is a very different task. So is any mileage on the M40, under 3 miles from North Hillingdon, where your engine has been running hard the whole time.
Driven until it protested. Clattering, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and your motor is saying so. Leave it wherever it has stopped: a lay-by, a side street, the verge on Windsor Avenue. What goes first is still the fuel drain and flush-through, and that takes care of it, with long-term damage very unusual when a car is pulled over early.
North Hillingdon motorists and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that guidance assumes.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that is how a newer diesel moves its fuel, so the protection counts for more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally will not run, and so the motorist stops — and the damage stops with them. Feed petrol to a diesel and it usually fires up, idles and pulls away as if nothing has happened — all while its pump is wearing. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated workaround for a distinct issue. None of what petrol thinned gets put back by it — and later, the tank still contains the petrol.
The next start sends petrol back round your pump out of the lines and the filter, where some of that ends up once the motor has been run. That is why draining your tank yourself doesn't leave you sorted — a myth. Clearing petrol into a can by the kerbside is also truly risky.
Petrol in a diesel: how does it happen?
A careless moment is rarely the cause, and no one means to do it. One way only, because of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it easy.
It takes place when routine and the car stop matching. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the driveway of the same household. A forecourt you know, only with its pumps arranged differently. A rushed fill en route to West Ruislip with a train to catch. Years of petrol vehicles behind you, a diesel Renault Clio in front of you on the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of children, and the hand does what it has always done.
North Hillingdon motorists: how to prevent petrol in a diesel next time
- The label is what counts, so read the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- Check your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on the first fill in any vehicle you do not know.
- One of each in the house? Mark your key to your diesel — a coloured fob, a sticker — since intending to remember isn't enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds silly. It does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that won't take a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- The moment you notice, stop: less petrol inside your tank means a weaker mix. What to do next does not change, though — still do not crank it.
North Hillingdon: already put petrol in a diesel?
Then, there is only a short order of things. Never crank it, and don't switch your ignition on. The attendants at the forecourt — whether at BP itself or wherever you filled up — will normally help roll it away from the pump if you ask. Ring 0333 366 0103 next, with three facts — the fuel, the approximate volume, and whether it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a different issue — North Hillingdon has a page all for it.
One petrol in a diesel job in North Hillingdon costs more than another. Why?
The four situations above are four separate jobs, so no single price for this would be fair. The situation itself does most of the work of moving the cost. Beyond that it's the share — how much petrol went in against how much that tank takes — and then where the vehicle is and whether our van can reach it safely.
What was put in, how much, and whether it has run — three queries our technicians ask before quoting, not after, for exactly that reason. The replies turn a range into a straight figure.
About North Hillingdon itself
North Hillingdon is a suburban area in northwest London, situated near the River Colne and the Grand Union Canal. North Hillingdon has a mix of terraced housing and other residential properties, with nearby amenities in Hillingdon and Ickenham. North Hillingdon sits at an elevation of around 36 metres, close to the rural landscapes of the Colne Valley, yet within commuting distance of central London.
North Hillingdon and Greater London: where our fuel drain cover reaches
North Hillingdon waits in the UB postcode area, and the vans that answer petrol in diesel jobs there work the places near it as well — Hillingdon, Ickenham and Hillingdon Heath among them. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
Still at the pump in North Hillingdon?
Then, you could not be in a better position. Switched off it stays; then phone.