How Worried Should You Be? Petrol in a Diesel Car in Lounsdale
Not started? Then less anxious than you likely feel. "Have I ruined it?" is the first thing anyone around Lounsdale asks, and the honest answer is normally no, because petrol resting in a diesel tank harms nothing till it is drawn through your fuel system — by ignition priming, by the starter, or by being driven. Leave your motor off and call Petrol in Diesel — that is how you keep it that way. The remainder of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
What petrol in a diesel does to the engine
Diesel does two jobs on its way through an engine. It burns, and before it burns it lubricates. Very fine clearances are built into your injectors and the high-pressure pump, and only the diesel running through keeps those surfaces from grinding together.
Of these two tasks, petrol manages the first badly and the second not at all. It's thinner than diesel and strips away the protection your fuel system rests on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
Put those together and the shape of the problem is plain. The damage is done by movement, not by contact. Where that petrol is only inside your tank, it's a problem of fuel, nothing more. The start of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with your fuel to your injectors downstream.
Lounsdale, petrol in a diesel: four cases, from mild to major
Fuelled but not once started — the best it gets. At a forecourt, and really only there, that petrol is still limited to your tank — because anywhere else the vehicle was driven to get to it. The task is emptying and cleaning on the spot.
A moment's running, or just the ignition on. Once primed, the fuel system has drawn petrol out of that tank as far as your filter and the lines. Drain, flush, see to the fuel filter: still normally straightforward.
Those few miles driven were the pump running on fuel thinned by petrol the whole way. Mileage is only half of it; how hard it was driven matters just as much. Either way this work includes the tank, the lines, your filter and clean fuel through the whole system. Short trips, such as the school run to the local primary school, are one thing. Very different again: a trip to Glasgow, under 10 miles away, or some distance on the M8, under 3 miles from Lounsdale, where the motor never stopped running hard.
Knocking, an uneven idle, smoke, a throttle gone soft: driven till it complained. That's the engine telling you its fuel no longer is acting like diesel. Stop on the spot — on the verge on Cross Road, at the kerb, down a side road — and don't move it. The drain and flush still go first, and they sort it out: if a vehicle is stopped quickly, lasting damage is very rare.
Petrol in a diesel myths Lounsdale drivers hear
Myth: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mix is all you get, since topping up takes out nothing. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a modern diesel copes with a bit of petrol. If anything, the reverse. Protection matters more on modern diesels, not less, because their fuel runs through smaller parts at higher pressure.
The myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor usually means a motor that won't run: the driver stops, and so does the harm. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Running isn't the same as fine.
An outdated fix for a distinct problem is behind this one. Myth: "Add some two-stroke oil and drive it home." The petrol is still in that tank afterwards, and what it has weakened is not put back.
Once your engine has run, part of the petrol sits in your filter and your lines, not your tank — and your next start sends it right back through your pump. So the myth "drain the tank yourself and you're sorted" doesn't hold. It's also really hazardous to drain petrol into a can by the roadside.
How does petrol in a diesel occur?
A careless moment is seldom the cause, and no one means to do it. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol motor at all. The forecourt makes it simple, and the error runs one way.
It takes place when habit and the vehicle stop matching. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps laid out differently. A rushed fill on the way to Paisley Canal with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it happens. With rain, a call arriving, or a car full of children to deal with, the hand simply does what it has always done.
Next time you fill up around Lounsdale: preventing petrol in a diesel
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of vehicles state the fuel type inside the filler flap or on the cap, so check it on your first fill in any car you don't know.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key when a home has one of each. So mark it.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a safety net, not a reason to stop reading the petrol pump.
- Stop as soon as you realise. Less petrol in the tank makes a weaker mix. It does not change what to do next, which is still not to start the vehicle.
Lounsdale: already put petrol in a diesel?
The order of things is brief, then. Do not switch your ignition on, and do not fire it up. Still at the forecourt, at Paisley Mill Service Station or anywhere else? Ask the attendants to help you push the vehicle clear of the petrol pump. Phone 0333 366 0103 next, with three facts — the fuel, the rough volume, and whether it has run.
Corrosion and deposits are the problem with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own Lounsdale page.
Lounsdale petrol in a diesel tasks: why one costs more than another
The four scenarios above are four different jobs, so no single quote for this would be honest. The scenario itself does most of the work of moving your cost. Where the vehicle is matters too, and whether a technician can safely reach it, after the ratio of petrol to what that tank holds.
Ahead of any quote, not after, we ask three queries: the fuel that went in, the volume, and whether it's run. That is why. Those replies change a range into a straight figure.
About Lounsdale, for a moment
Lounsdale is a suburban area situated on the riverside in Renfrewshire, with a relatively low elevation of 27 metres. Lounsdale lies close to the city of Glasgow, approximately 8.5 miles away, and is near other local places such as Meikleriggs and Stanely. Lounsdale has a population of around 5986 people, predominantly residing in flat-type housing.
Across Renfrewshire and in Lounsdale: fuel drain cover
Meikleriggs, Stanely and Brediland are among the places around Lounsdale that the same teams work, answering petrol in diesel call-outs across Lounsdale's PA postcode area. We drain where the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the petrol pump around Lounsdale, still?
Then you're in the best place there can be. Ring, and keep it switched off.