How Worried Should You Be? Petrol in a Diesel Car in Invernettie
If it hasn't been started, worry far less than you probably are. Until your ignition primes the pump, the starter turns, or your car is driven, petrol in a diesel tank just sits there and does no harm. Which makes the honest reply to the first Invernettie question — "have I wrecked it?" — usually no. Petrol in Diesel is who to call, with the motor left off, so it remains that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and ways to make sure you don't repeat it.
The motor and petrol in a diesel: what happens
Passing through an engine, diesel does two things at once. It lubricates to begin with, and after that does it burn. What stops the surfaces inside your high-pressure pump and your injectors from wearing down against one another is the diesel passing through them — they are made to extremely fine clearances.
Badly at the first, not at all at the second: that's petrol. It is runnier than diesel and takes away the protection the system rests on, and so a pump running on a petrol mix 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 is where the knocking comes from.
Put those together and the shape of the problem is clear. It's circulation that causes the harm, not contact. Petrol in a tank is a fuel issue. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream.
Four situations our engineers see around Invernettie: how bad is petrol in a diesel?
Fuelled but not once started — as good as it gets. That petrol is in your tank and only your tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only truly happen at a forecourt, because anywhere else the car has been driven to get there.
A brief spell of running, or merely the ignition on. The system has been bled, so petrol has left your tank and got to the filter and the lines. Still generally straightforward: drain, flush, and your filter seen to.
Some miles driven, and your pump has spent every one of them running on diluted fuel. The work is the tank, your lines, your filter and clean fuel through the whole system, and how hard the car was driven counts as much as how far. On the school run to the local primary school, the mileage is short. A run as far as Aberdeen, under 50 miles away, is a very different task. So is any miles on the M90, over 50 miles from Invernettie, where your engine has been labouring hard throughout.
Driven on till it complained — rattling, smoke, an uneven idle, a soft throttle. The engine is telling you your fuel is no longer behaving like diesel. Pull up wherever you are — the verge on South Road, a lay-by, a side street — then leave it there. What comes first is still the fuel drain and flush, and that deals with it, with lasting damage very rare when a car is pulled over early.
What Invernettie people get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you're left with a bigger tank, still the same mix. The assumption behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through more precise parts: that is how a modern diesel moves its fuel, so the lubrication counts more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. Diesel in a petrol motor generally leaves a motor that will not run: the motorist stops, and so does the damage. A diesel fed petrol generally starts, idles and drives away as though nothing has happened, whilst the pump grinds. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an old fix for a separate problem. It doesn't put back what petrol has weakened, and the petrol is still inside your tank later on.
Myth: "Drain that tank yourself and you are sorted." After your engine has been run, some of the petrol is no longer inside that tank: it is in the filter and your lines, and it goes right back through the pump at the next start. On top of that, petrol emptied into a can by the road is truly hazardous.
How petrol ends up: petrol in a diesel
Carelessness is seldom the cause, and no one means to do it. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol car. That is how the forecourt makes it easy.
When habit and your car stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill en route to the nearest station. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. The hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
How to prevent petrol in a diesel at your next fill-up in Invernettie
- The label is what matters, so check the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on each forecourt.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before the first fill: many motors print the fuel there.
- One of each in the house? Mark your key to your diesel — a bright fob, a sticker — because meaning to remember is not enough.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to block a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop checking the pump.
- Noticing it mid-fill? Stop at once. A thinner mixture follows from less petrol inside the tank, yet your next step remains the same: don't start it.
Already put petrol in a diesel in Invernettie?
Then the order of things is short. Leave it unstarted, with the ignition switched off as well. If you're still at the forecourt — Shell or anywhere else — ask the attendants to help you roll the car away from the petrol pump. Then call 0333 366 0103 and tell us what got in, about how much, and whether it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Invernettie has a page just for it.
What makes one Invernettie petrol in a diesel task cost more than the next
An honest single price doesn't exist here: four situations, four separate jobs. Mostly, the cost shifts with which situation you are in. Beyond that it is the ratio — how much petrol got in against how much that tank holds — and after that where your car is and whether a van can get to it safely.
What was put in, how much, and if it's run — three questions our engineers ask before costing, not after, for precisely that reason. With the answers, there is a straight figure instead of a range.
About Invernettie itself
Invernettie is a coastal suburban area in Aberdeenshire, situated near the towns of Whitehill and Meethill. Invernettie lies at an elevation of 22 metres, close to the Clerkhill area, and is characterized by its semi-detached housing stock. Invernettie is located approximately 25.9 miles from Aberdeen, the nearest city, and is home to around 1017 residents. Invernettie forms part of the wider residential area surrounding Aberdeen, with the city's amenities within reach.
Invernettie and Aberdeenshire: where our fuel drain cover reaches
Invernettie sits in the AB postcode area, and our vans that answer petrol in diesel call-outs there work the spots around it as well — Whitehill, Meethill and Clerkhill among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and your car does not need to move to us.
In Invernettie and still at the petrol pump?
Then you are in the best spot there can be. Call, and keep it switched off.