Limehouse: Petrol in a Diesel Car? How Worried to Be
Probably less than you are now — provided nobody has started the vehicle. Everyone in Limehouse begins with "have I wrecked it?", and the fair answer is normally no: petrol resting inside your tank of a diesel stays harmless until priming, cranking or driving pulls it into the fuel system. Keep it like that: leave your engine off then call Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and the way to make sure you don't repeat it.
What petrol in a diesel does to your engine
Diesel has two tasks on its way through an engine. Before it combusts, it protects — then it ignites. The high-pressure fuel pump and your injectors are made to very fine clearances, and the diesel passing through them is what keeps those surfaces from wearing down against each other.
The second task petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump on that mixture to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
Put those together and the shape of the trouble is plain. It is circulation that causes the harm, not contact. Where that petrol is only inside the tank, it's a problem of fuel, nothing more. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
Four scenarios we see around Limehouse: how serious is petrol in a diesel?
The best case there is: filled up, not once started. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in the tank alone, it is drained and flushed on the spot, and nothing more is needed.
Ignition on, or started for a second. The system has been bled, so petrol has left the tank and reached the filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually easy.
Driven a few miles. Now the pump has spent those miles working on weakened fuel. Distance is only half of it; how hard it was driven counts equally. Either way the work runs to that tank, your lines, the fuel filter and fresh fuel through the whole system. The school run to Sir William Burrough Primary School is one matter. Very different again: a run to London, under 3 miles away, or some mileage on the M11, under 10 miles from Limehouse, where your engine kept labouring hard.
Driven till it complained. Rattling, an uneven idle, smoke, a throttle that has gone soft. That's the motor telling you its fuel has stopped behaving like diesel. Whether it is the verge on Rhodeswell Road, a lay-by or a side road, stop there and leave it. The fuel drain and flush still go first, and they take care of it: when a car is pulled over quickly, lasting damage is very rare.
Limehouse motorists and the petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It does not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. The idea behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through finer parts: that's how a newer diesel moves its fuel, so the lubrication counts more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools drivers. The driver of a petrol motor fed diesel normally stops, since it will not run, and the harm stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. Running is not the same as fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. None of what petrol thinned is put back by it — and later, the tank still holds that petrol.
The next start draws petrol back round the pump out of the fuel lines and your filter, where some of it sits once the motor has been run. That is why draining the tank yourself does not leave you sorted — a myth. Clearing petrol into a can by the roadside is also really risky.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
When habit and your car stop matching, it happens. A new motor, a hire car or a courtesy car. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. A rushed fill en route to the nearest station with a train to catch. Years of petrol cars behind you, a diesel Audi A4 in front of you at the forecourt for its first tank — that's when. With rain, a call arriving, or children to deal with, the hand just does what it always has.
Limehouse people: how to avoid petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — yet not on each forecourt. Trust the label on the petrol pump, not the colour.
- Check your filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on the first fill in a car you do not know.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key if a household has one of each. So mark 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 petrol pump. It seems silly and it does the trick.
- Mistakes like this are easy to make while your mind is on something else, and so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for the remainder. Treat it as a safety net, then keep reading the petrol pump.
- Stop the moment you realise. Less petrol inside your tank means a weaker blend. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel in Limehouse already?
The order of things is short, then. Starting it is out, and so is switching on the ignition. The attendants at the forecourt — whether at Texaco itself or wherever you filled up — will normally help push it away from the petrol pump if you ask. Ring 0333 366 0103 next, with three facts — the fuel, the rough volume, and if it has run.
Say so if it was AdBlue instead of petrol: it's a different fault, with its own page for Limehouse, because AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job around Limehouse costs more than another
There is no fair single quote for this, because the four scenarios above are four separate jobs. What shifts the cost is chiefly which of them you are in. Two things come after that: the petrol that went in as a proportion of what your tank takes, then the place the vehicle is in and whether a technician can reach it safely.
That is why our technicians ask three queries before costing instead of after: what was put in, how much, and if it has run. A range turns into a straight figure once the answers are in.
About Limehouse and where it is
Limehouse is a suburban area in East London, situated on the north bank of the River Thames at an elevation of around 13 metres. Limehouse is characterized by its predominantly flat-type housing and is located close to other nearby places such as the Frank Whipple Estate and Coalmakers Wharf. Limehouse has a population of approximately 27627 residents and is near the historic area of Ratcliff. Limehouse is also just 2.5 miles from the city of London, making it a popular residential choice.
Fuel drain cover across Greater London, Limehouse included
Frank Whipple Estate, Coalmakers Wharf and Ratcliff are among the places around Limehouse that the same vans work, answering petrol in diesel jobs across Limehouse's E postcode area. The vehicle doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Limehouse: still at the petrol pump?
No position is better: that is where you now are. Keep it off. Ring.