Petrol in a Diesel Car in Inchbrook: How Worried Should You Be?
If it has not been started, you can worry less than you probably are. Until the ignition primes your pump, your starter cranks, or the car is driven, petrol in a diesel tank simply waits there and does no harm. Which makes the truthful reply to the first Inchbrook query — "have I wrecked it?" — usually no. To keep the vehicle that way, ring Petrol in Diesel then leave your engine switched off. The remainder of this page covers what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Petrol in a diesel: what does it do to your engine?
On its way through a motor, diesel has two jobs. It protects first, and only then does it burn. The high-pressure pump and the injectors are made to very fine tolerances, and the diesel passing through them is what keeps those surfaces from wearing against each other.
Badly at the first, not at all at the second: that's petrol. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the lubrication your fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any rattling comes.
The shape of the problem is clear once you put those together. The harm is done by circulation, not by contact. Where the petrol is only inside your tank, it's a fault of fuel, nothing more. The beginning of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Four situations our engineers see in Inchbrook: how serious is petrol in a diesel?
The best case there is: filled up, never started. That petrol is inside your tank and only that tank, and the job is a drain and a flush where the car stands. This is the one scenario that can only truly take place on a forecourt, because anywhere else your car has been driven to get there.
Ignition on, or started for a second. The fuel system has been primed, so petrol has left your tank and reached your filter and your lines. Still normally simple: drain, flush, and the filter seen to.
Driven a couple of miles. Now the pump has spent these miles running on thinned fuel. Miles is only half of it; how hard it was driven counts just as much. Either way this work runs to the tank, the fuel lines, the fuel filter and clean fuel through the entire circuit. Short trips, like the school run to Nailsworth Church of England Primary School, are one matter. Driving as far as Gloucester, under 15 miles away, makes a very different job — as does any distance on the M5, under 10 miles from Inchbrook, with the motor running hard the whole time.
Driven till it protested. Clattering, a ragged idle, smoke, a throttle that has gone soft. The fuel is not acting like diesel any more, and your engine is saying so. Stop wherever you are — the verge on Inchbrook Hill, a lay-by, a side street — then leave the vehicle where it is. Permanent damage is very unusual if a vehicle is pulled over quickly, and the drain and flush-through that still go first sort it out.
Inchbrook drivers and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed when you top up — the tank simply holds more of the same blend. Percentage isn't how a diesel fuel system tolerates petrol, however much that advice presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Protection counts more on current diesels, not less, since their fuel runs through finer components at higher pressure.
Myth: "If it starts and drives, there's no harm done." This is the one that fools people. Diesel in a petrol motor usually means a motor that will not run: the motorist stops, and so does the harm. Whilst your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Fine and running are not the same thing.
An old fix for a different problem lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol weakened gets put back by it — and later, that tank still contains the petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol sits in the filter and lines, waiting to go straight back through your pump on the next start. Also, a can of petrol drained at the kerbside is genuinely risky.
How does petrol in a diesel occur?
Carelessness is rarely the cause, and nobody means to do it. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol motor. That is how the forecourt makes it straightforward.
It happens when habit and your car stop matching. Any vehicle that is new to you — hired, on loan as a courtesy car, or brand new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. A rushed fill on the way to Stroud with a train to catch. Years of petrol cars behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
Inchbrook people: how to avoid petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what matters.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles state the fuel there.
- Label the key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you lift the nozzle — every 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, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a safety net, and keep reading the petrol pump.
- Less petrol means a thinner blend, so stop as soon as you realise — though remembering that your next stage is unchanged. It is still not to fire it up.
Put petrol in a diesel around Inchbrook already?
Short and simple, then, is the order of things. Starting it is out, and so is turning on the ignition. The staff on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it clear of the petrol pump if you ask. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it's been run.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Inchbrook page.
One petrol in a diesel job around Inchbrook costs more than another. Why?
Four separate jobs sit behind the four scenarios above — which is why there's no fair single quote. What moves the cost is chiefly which of them you are in. Where the car is counts too, and whether our van can safely get to it, after the proportion of petrol to what that tank takes.
Before any quote, not after, come three questions: your fuel that went in, its amount, and whether it's run. That is why. The replies turn a range into a straight figure.
About Inchbrook and where it is
Inchbrook is a suburban area situated on the riverside in Gloucestershire, with an elevation of around 89 metres. Inchbrook lies approximately 11 miles from Gloucester and 91 miles from London, placing it in a commuter belt with access to major cities. Inchbrook is characterised by its semi-detached housing stock and is surrounded by nearby places such as Windsoredge and Forest Green. Inchbrook has a population of around 1822 residents.
Fuel drain cover around Inchbrook and across Gloucestershire
Our teams answering petrol in diesel call-outs around Inchbrook, in the GL postcode area, also work the spots near it, Windsoredge, Forest Green and Theescombe included. We drain wherever the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the petrol pump around Inchbrook, right now?
Then you're in the best spot there is. Keep it switched off, then ring.