How Worried Should You Be? Petrol in a Diesel Car in Bank Lane
Not started? Then less worried than you likely feel. Until the ignition primes the pump, your starter cranks, or the vehicle is driven, petrol in a diesel tank just sits there and does no harm. Which means the honest reply to that first Bank Lane question — "have I wrecked it?" — normally no. To leave it that way, phone Petrol in Diesel then leave the engine switched off. Further down, this page sets out what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Passing through a motor, diesel does two things at the same time. Lubricating comes before burning; it does both. What keeps the surfaces inside your high-pressure pump and your injectors from grinding against one another is the diesel flowing through them — they are built to extremely fine gaps.
Of those two jobs, petrol handles the first badly and the second not at all. It is thinner than diesel and removes the lubrication the fuel system hinges on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Together, those make the shape of the issue plain. Not contact but circulation is what causes the damage. Petrol in a tank is a fuel problem. After your pump has been working on that petrol, a mechanical issue has begun: anything shed by a pump that is grinding travels onward to the fuel injectors with the fuel.
Four situations our technicians see in Bank Lane: how serious is petrol in a diesel?
Fuelled up, not once started. The best case there is. That petrol is in that tank and only that tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only really occur at a forecourt, as anywhere else the vehicle has been driven to get there.
The ignition turned on, or a brief start. Your system has been bled, and so petrol has left that tank and got to your filter and your lines. Drain, flush, see to the fuel filter: still usually simple.
Driven a few miles. Now your pump has spent these miles working on thinned fuel. How hard the car was driven matters as much as how far, and the work covers that tank, the fuel lines, the filter and clean fuel through the entire system. Driving the kids to Peel Brow School is one kind of trip. Very different again: a trip to Salford, under 15 miles away, or any distance on the M66, under a mile from Bank Lane, where the motor kept labouring hard.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. What you are hearing is the engine reporting fuel that no longer runs like diesel. Stop on the spot — on the verge on Henry Street, at the kerb, down a side road — and don't move it again. A vehicle stopped soon very rarely has permanent damage, as the drain and the flush, which still come first, deal with it.
Petrol in a diesel myths Bank Lane people hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A bigger tank of the same mix is all it gives, since topping up takes out nothing. A diesel fuel system doesn't accept petrol by percentage in the way that guidance presumes.
If anything, the opposite is true. Myth: "A current diesel can cope with a bit of petrol." A modern diesel sends its fuel through more precise components at higher pressure, which makes the protection count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no damage done." The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the damage stops with them. Feed petrol to a diesel and it normally fires up, ticks over and drives away like nothing happened — all the while its pump is wearing. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated fix for a different fault. What petrol has diluted remains thinned, and the petrol remains in the tank anyway.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol lies in your filter and lines, waiting to go right back through your pump on your next start. Also, a can of petrol filled by the kerbside is genuinely dangerous.
How it happens: petrol in a diesel
Carelessness is rarely the cause, and no one means to do it. The petrol nozzle is the narrower of the two and slides 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.
It occurs when routine and the vehicle stop matching. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. Fuelling up in a hurry en route to Entwistle, with a train to catch. Years of petrol vehicles behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
Avoiding petrol in a diesel next time you fill up in Bank Lane
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what matters.
- Check the filler flap. Plenty of cars state the fuel inside the flap or on the cap. Look at it on your first fill in any motor you do not know.
- Good intentions do 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.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels have a filler designed to refuse 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 checking the pump.
- Stop as soon as you notice. Less petrol inside that tank makes a weaker mix. It doesn't change what to do next, which is still not to crank it.
Put petrol in a diesel in Bank Lane already?
Then, there is just a short order of things. Leave it unstarted, with the ignition off as well. Ask the attendants to help you push it away from the petrol pump if you are still at the forecourt, whether that's EG On the Move or somewhere else. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That is a separate problem — corrosion and deposits rather than lost lubrication — and it has its own page for Bank Lane.
Bank Lane petrol in a diesel tasks: why one costs more than another
Four separate jobs lie behind the four situations above — which is why there is no fair single quote. Which of them you're in is chiefly what shifts your cost. Beyond that it is the share — how much petrol got in against how much your tank takes — and after that where the car is and whether our van can get to it safely.
Three questions come first, before quoting, instead of after — what was put in, how much, has it run — and this is the reason. Their replies are what turn a range into one firm number.
About Bank Lane, briefly
Bank Lane is a suburban area in Greater Manchester, situated near the riverside and characterised by its terraced housing. Bank Lane sits at an elevation of 193 metres, overlooking the surrounding landscape. Bank Lane is located near several other suburban areas, including Fletcher Bank, Peel Brow, and Shuttleworth, and is approximately 11.7 miles from Salford. Bank Lane has a population of around 1493 residents.
Fuel drain cover around Bank Lane and across Greater Manchester
Fletcher Bank, Peel Brow and Shuttleworth are among the spots around Bank Lane that the same vans work, answering petrol in diesel calls across Bank Lane's BL postcode area. Our engineers drain where the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Bank Lane and still at the petrol pump?
The best position there is, then — that's where you are. Ring, and keep it switched off.