How Worried Should You Be? Petrol in a Diesel Car in Bridgend
Likely less than you already are — provided no one has started the vehicle. Everyone in Bridgend starts with "have I wrecked it?", and the honest answer is usually no: petrol left inside your tank of any diesel remains harmless until priming, cranking or driving draws it into your fuel system. Petrol in Diesel is who to call, with your engine left off, and so it stays that way. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and ways to make sure you never repeat it.
Inside your engine: what petrol in a diesel really does
Passing through an engine, diesel does two jobs at once. It combusts, and before it burns it lubricates. Designed to extremely fine tolerances, your injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Badly at the first, not at all at the second: that is petrol. A pump working on a petrol mix is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where the knocking comes.
Combined, those make 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 problem. After the pump has been labouring on that petrol, a mechanical problem has begun: anything shed by a pump that's wearing is carried downstream to the fuel injectors with your fuel.
Four situations our engineers see around Bridgend: how bad is petrol in a diesel?
Fuelled but not once started — the best it gets. The petrol is inside the tank and just the tank, and the task is a drain and a flush where your car sits. This is the one scenario that can only truly happen at a forecourt, since anywhere else your car has been driven to get there.
Your ignition turned on, or a brief start. Once primed, the fuel system has drawn petrol out of the tank up to your filter and your lines. Usually nothing more than clearing, purging and sorting the filter, and so still straightforward.
Some miles driven, and the pump has spent each of them working on weakened fuel. Tank, lines, filter, then clean fuel put through the entire system: that is the work, and the way the car was driven matters as much as the mileage. The school run to St Winnow CofE School is one thing. Driving as far as Truro, under 25 miles away, makes a very different task — as does any distance on the M5, over 50 miles from Bridgend, with the motor running hard the whole time.
Driven till it complained. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel is not acting like diesel any more, and your engine is telling you. Leave it where it stops: a lay-by, a side street, the verge on Lanwithan Road. A car pulled over quickly very rarely has permanent damage, because the fuel drain and the flush-through, which still come first, deal with it.
Myths Bridgend people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. A bigger tank of the same mixture is all you get, since topping up removes nothing. The idea behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that's how a newer diesel moves its fuel, and so the lubrication counts more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." Feed diesel to a petrol motor and it generally will not run, so the driver stops — and the harm stops with them. Whilst the pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a different problem. It doesn't put back what petrol has diluted, and that petrol is still in your tank later.
If your engine has run, part of that petrol is in the fuel filter and the fuel lines, not the tank — and your next start pulls it straight back through the pump. So the myth "drain the tank yourself and you're sorted" doesn't stand up. On top of that, petrol cleared into a can by the road is genuinely risky.
Why petrol in a diesel takes place so easily
On purpose? Never. Through carelessness? Rarely, if ever. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol vehicle. That's how the forecourt makes it simple.
The moment habit stops matching the car is the moment it occurs. A new car, a hire car or a courtesy car. Two motors on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Rushing for a train at Lostwithiel and filling up en route. Years of petrol motors behind you, a diesel Renault Megane in front of you at 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 does what it has always done.
Next time you fill up around Bridgend: preventing petrol in a diesel
- The label is what counts, and so check the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on every forecourt.
- Plenty of motors state the fuel type inside the filler flap or on the cap, and so check there on your first fill in a vehicle you don't 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 label it.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, perhaps, yet it works.
- Mistakes like this are straightforward 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 built to refuse a petrol nozzle, and aftermarket devices exist for the rest. Count it as a safety net, and keep checking the pump.
- Spotting it halfway? Stop there and then. A thinner mix results from less petrol inside your tank, yet your next step stays the same: don't fire it up.
Already put petrol in a diesel in Bridgend?
Then the order of things is short. Leave it unstarted, with your ignition switched off as well. Still on the forecourt, at Gulf or anywhere else? Ask the staff to help you push the vehicle clear of the pump. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it has been run.
If it was AdBlue and not petrol, say so. That's a separate problem — corrosion and deposits instead of lost lubrication — and it has its own page for Bridgend.
Why one petrol in a diesel task around Bridgend costs more than another
A fair single price does not exist here: four situations, four separate jobs. What shifts the cost is mostly which of them you're in. The share counts next, meaning how much of your tank is petrol, followed by the location of your car and whether reaching it is safe for our van.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and that is the reason. Given those answers, you get a straight figure instead of a range.
About Bridgend
Bridgend is a suburban area in Cornwall, situated on the banks of a river at an elevation of 19 metres. Bridgend lies near the towns of Lostwithiel and Truro, and is part of a network of settlements including Downend and Sandylake. Bridgend has a population of approximately 2285 people, and its housing stock is predominantly made up of detached homes. Bridgend is located 211.5 miles west of London, in the South West region of England.
Across Cornwall and in Bridgend: fuel drain cover
Petrol in diesel jobs around Bridgend — part of the PL postcode area — go to vans that likewise cover the locations about it, Lostwithiel, Downend and Sandylake included. The car doesn't need to move to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump around Bridgend?
Then you're in the best spot there can be. Ring, and keep it turned off.