How Worried Should You Be? Petrol in a Diesel Car in West Craigend
Not started? Then less anxious than you probably are. Petrol sitting in a diesel tank does nothing to the engine until something pulls it through the system — your ignition priming the pump, the starter, or the drive on its own. So the fair answer to the first question anyone around West Craigend asks, "have I ruined it?", is generally no. Leave the engine off then call Petrol in Diesel — that is how you keep it like that. Read on for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and the way to make sure you don't repeat it.
Petrol in a diesel: what does it do to your engine?
On its way through an engine, diesel does two jobs. It lubricates first, and after that does it burn. The high-pressure pump and the injectors are designed to very fine tolerances, and your diesel passing through them is what keeps those surfaces from grinding against each other.
The second job petrol does not do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and strips out the protection your 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 is where the clattering starts.
Put those together and the shape of the issue is clear. The damage is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel fault. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to your injectors further on.
Four scenarios we see around West Craigend: how bad is petrol in a diesel?
The best case there can be: filled up, never started. That petrol is in that tank and just that tank, and the job is a drain and a flush where your car sits. This is the one situation that can only truly occur on a forecourt, since anywhere else the car has been driven to get there.
The ignition switched on, or a brief start. Your system has been primed, so petrol has left the tank and got to the fuel filter and the lines. Drain, flush, see to your filter: still usually simple.
Driven a couple of miles. Now the pump has spent these miles labouring on weakened fuel. The work is the tank, the lines, your filter and clean fuel through the whole circuit, and how hard your car was driven matters as much as how far. On the school run to the local primary school, the distance is short. A run as far as Glasgow, under 10 miles away, is a very different job. So is any distance on the M898, under a mile from West Craigend, where your engine has been working hard the whole time.
Driven on till it complained — clattering, smoke, a ragged idle, a soft throttle. That's your motor telling you its fuel no longer is behaving like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Millfield Meadows. What comes first is still the drain and flush, and that deals with it, with permanent damage very unusual when a car is pulled over quickly.
What West Craigend people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed when you top up — that tank simply holds more of the same mixture. Percentage isn't how a diesel fuel system tolerates petrol, however much that guidance presumes.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. Lubrication counts more on current diesels, not less, because their fuel passes through finer parts at higher pressure.
This is the one that fools motorists. Myth: "If it starts and drives, there is no harm done." The motorist of a petrol engine fed diesel usually stops, because it will not run, and the damage stops with them. While the pump wears, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Running isn't the same as fine.
An outdated workaround for a different issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It does not put back what petrol has thinned, and the petrol is still in the tank later.
The next start sends petrol back round your pump from the lines and your filter, where some of it ends up once your engine has been run. That's why draining the tank yourself does not leave you sorted — a myth. Emptying petrol into a can by the kerbside is also really risky.
How does petrol in a diesel happen?
A careless moment is rarely the cause, and no one means to do it. One way only, since of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol motor. That is how the forecourt makes it simple.
Routine and the car getting out of step is when it takes place. A new car, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. Your usual forecourt, its pumps now in a different order. A train to catch, and a rushed fill on the way to Bishopton. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. With rain, a call arriving, or children to deal with, the hand just does what it has always done.
Next time you fill up around West Craigend: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a strange vehicle is the time to check your filler flap — inside it, or on the cap, plenty of cars state which fuel they take.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key if a household has one of each. So mark it.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It seems daft. It does the trick.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and add-on devices exist for the rest. Count it as a safety net, and keep checking the petrol pump.
- Less petrol means a weaker blend, and so stop the moment you realise — though remembering that your next stage is unchanged. It's still not to start the car.
West Craigend: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't start it, and don't turn the ignition on. Still on the forecourt, at Shell or anywhere else? Ask the staff to help you roll the vehicle away from the petrol pump. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it's been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate problem — West Craigend has a page all for it.
One petrol in a diesel task in West Craigend costs more than another. Why?
The four scenarios above are four separate jobs, so no single quote for this would be fair. The scenario itself does most of the work of moving your cost. After that it's the proportion — how much petrol was put in against how much the tank holds — and then where the car is and whether our van can get to it safely.
Ahead of any quote, not after, we ask three questions: the fuel that was put in, the quantity, and whether it's run. That's why. Those replies turn a range into a straight figure.
About West Craigend
West Craigend is a suburban area in Renfrewshire, situated near the coast and approximately 9 miles west of Glasgow. West Craigend has a relatively low elevation of 37 metres and is characterised by detached housing. West Craigend is close to nearby places such as Linburn and East Craigend, and is part of the wider Glasgow urban area.
Fuel drain cover around West Craigend and across Renfrewshire
Linburn, East Craigend and Erskine are among the spots around West Craigend that the same vans work, answering petrol in diesel jobs across West Craigend's PA postcode area. We drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
West Craigend: still at the petrol pump?
The best position there is, then — that's where you are. Keep it off. Phone.