Should You Worry? Petrol in a Diesel Car in Grangemouth
Less than you probably are, provided it hasn't been started. Till the ignition primes the pump, your starter turns, or the car is driven, petrol in a diesel tank simply sits there and does no harm. Which makes the honest reply to the first Grangemouth query — "have I ruined it?" — usually no. Keep it like that: leave the engine off then ring Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it has gone, and how to stop it from happening again: that's the remainder of this page.
Petrol in a diesel: what does it do to the engine?
Two jobs fall to diesel on its route through a motor. It ignites, and before it burns it protects. Very fine clearances are built into the injectors and the high-pressure pump, and only your diesel running through keeps those surfaces from grinding together.
Poorly at the first, not at all at the second: that's petrol. A pump working on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the protection 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 the knocking comes.
Combined, those make the shape of the trouble plain. It's circulation that causes the damage, not contact. A tank with petrol in it is a fuel issue. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors beyond it.
Four situations our engineers see in Grangemouth: how bad is petrol in a diesel?
Fuelled but not once started — the best it gets. On a forecourt, and truly only there, that petrol is still confined to the tank — because anywhere else your car was driven to get to it. The job is emptying and rinsing on the spot.
A moment's running, or merely your ignition on. Once primed, the fuel system has drawn petrol from the tank up to your filter and the fuel lines. Usually little more than clearing, flushing and seeing to your filter, and so still straightforward.
Some miles driven, and your pump has spent every one of them running on diluted fuel. How hard your car was driven counts as much as how far, and this work covers your tank, the fuel lines, your filter and clean fuel through the entire system. On the school run to the local primary school, the mileage is short. Driving as far as Stirling, under 15 miles away, makes a very different task — as does any mileage on the M9, under 3 miles from Grangemouth, with the motor running hard the whole time.
Driven until it complained. Rattling, an uneven idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer behaving like diesel. Whether it's the verge on Station Road, a lay-by or a side street, stop there and leave it. What goes first is still the drain and flush, and that takes care of it, with long-term damage very uncommon when a vehicle is stopped soon.
Stories Grangemouth motorists hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A bigger tank of the same mix is all you get, since topping up removes nothing. That advice supposes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through finer parts: that's how a modern diesel moves its fuel, and so the lubrication counts for more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." Any petrol engine fed diesel usually won't run, so the motorist stops and the harm stops with them. While your pump grinds, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Running isn't the same as fine.
An old fix for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has diluted remains thinned, and that petrol stays in the tank anyway.
Myth: "Drain that tank yourself and you are sorted." After the motor has been run, some of that petrol is no longer inside the tank: it is in your filter and the fuel lines, and it goes straight back through the pump on the next start. Besides, petrol emptied into a can by the road is genuinely hazardous.
How does petrol in a diesel occur?
Nobody does it on purpose, and it's seldom carelessness. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
When routine and the car stop matching, it takes place. Courtesy car, hire car, or a motor that's brand new. A household with one petrol and one diesel on the driveway. A familiar forecourt with the pumps in a different order. A train to catch, and a rushed fill on the way to Polmont. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. Throw in a back seat full of children, a phone call or rain, and habit wins.
Grangemouth drivers: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the petrol pump's label; the colour is just a hint.
- Check the filler flap. Many cars state the fuel inside the flap or on the cap. Look at it on your first fill in any vehicle you do not know.
- One of each in the house? Label your key to the diesel — a bright fob, a sticker — because intending to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It sounds daft. It does the trick.
- Put the phone away. This is an easy mistake to make while you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and aftermarket devices exist for the remainder. Count it as a safety net, then keep checking the pump.
- As soon as you realise, stop: less petrol in your tank means a thinner mixture. What to do next does not change, though — still don't crank it.
Already put petrol in a diesel around Grangemouth?
Short and simple, then, is the order of things. Starting it is out, and so is turning on your ignition. Ask the attendants to help you roll it clear of the petrol pump if you're still on the forecourt, whether that's Asda or somewhere else. Next, 0333 366 0103. We'll 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 different problem — corrosion and deposits rather than lost lubrication — and it has its own page for Grangemouth.
What makes one Grangemouth petrol in a diesel job cost more than the next
There is no honest single price for this, because the four situations above are four separate jobs. The scenario itself does most of the work of moving your cost. Where the vehicle is matters too, and whether our van can safely get to it, after the ratio of petrol to what that tank holds.
Three queries come first, before any quote, instead of after — what went in, how much, has it run — and that is the reason. Those replies change a range into a straight figure.
About Grangemouth
Grangemouth is a coastal town in Falkirk, situated on the south bank of the Firth of Forth, with a population of around 9513 people. Grangemouth has a relatively low elevation of 7 metres above sea level and is located near several smaller communities, including Glensburgh, Bowhouse, and Skinflats. Grangemouth is characterized by a high proportion of flat-type housing, reflecting its urban nature. Grangemouth is also positioned near the city of Stirling, which is approximately 10.5 miles away.
Grangemouth and Falkirk: where our fuel drain cover reaches
Petrol in diesel calls around Grangemouth — part of the FK postcode area — go to vans that likewise cover the locations round it, Glensburgh, Bowhouse and Skinflats among them. The vehicle doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Grangemouth: still at the petrol pump?
Then, you couldn't be in a better place. Switched off it stays; then phone.