Should You Worry? Petrol in a Diesel Car in Linthouse
If it has not been started, you can worry less than you likely are. "Have I wrecked it?" is the first question everyone in Linthouse asks, and the truthful answer is normally no, since petrol left in a diesel tank harms nothing until it's dragged through the system — by ignition priming, by the starter, or by being driven. Keep it like that: leave your motor off then call Petrol in Diesel. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
Inside your engine: what petrol in a diesel really does
Two jobs fall to diesel on its journey round a motor. It ignites, and before it burns it lubricates. What keeps the surfaces inside the high-pressure pump and the fuel injectors from grinding against each other is your diesel flowing through them — they're built to very fine clearances.
Badly at the first, not at all at the second: that is petrol. It's thinner than diesel and removes the lubrication your fuel system depends on, and so a pump running on a petrol mixture 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 rattling comes from.
Taken together, they show what shape the problem has. The harm is done by movement, not by contact. Petrol in a tank is a fuel issue. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
How serious is petrol in a diesel? Four situations our technicians see in Linthouse
Fuelled but never started — as good as it gets. Only the tank has petrol in it, so the task is draining your tank and cleaning the fuel system where your car sits. This scenario can only truly occur at a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a moment. Petrol has come out of that tank and reached your filter and the fuel lines, since the fuel system has been primed. Normally nothing more than emptying, cleaning and sorting the fuel filter, so still straightforward.
Those few miles on the road were your pump running on fuel weakened by petrol throughout. Miles is only half of it; how hard it was driven matters equally. Either way the work runs to the tank, your lines, your filter and fresh fuel through the whole system. On the school run to the local primary school, the mileage is small. Driving as far as Glasgow, under 5 miles away, makes a very different task — as does any mileage on the M8, under a mile from Linthouse, with the engine running hard all the way.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone lumpy. That is your engine telling you its fuel no longer is acting like diesel. Whether it's the verge on Burghead Place, a lay-by or a side road, stop where you are and leave it. Permanent damage is very unusual when a car is pulled over soon, and the drain and flush that still go first deal with it.
Myths Linthouse people hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a bigger tank of the same mixture. That advice supposes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel sends its fuel through smaller parts at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. A petrol engine fed diesel generally won't run, and so the motorist stops and the harm stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, while the pump grinds. A running engine does not mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an old fix for a different fault. None of what petrol diluted is put back by it — and afterwards, that tank still contains that petrol.
Myth: "Drain that tank yourself and you are sorted." Once the motor has run, some of the petrol is no longer inside that tank: it is in the fuel filter and the lines, and it goes straight back through your pump on the next start. Also, a can of petrol drained by the kerbside is genuinely risky.
Petrol in a diesel: how does it take place?
It's seldom carelessness, and no one does it on purpose. One way only, because of the nozzles: the slimmer 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 vehicle is the moment it occurs. Courtesy car, hire car, or a vehicle that's new. Two vehicles on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Racing for a train outside Cardonald and filling up en route. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. Add rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up around Linthouse
- Green for unleaded and black for diesel is normal in the UK — yet not on each forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a new vehicle is the time to check the filler flap — inside it, or on the cap, plenty of cars state which fuel they take.
- One of each in the household? Label the key to the diesel — a coloured fob, a sticker — since meaning to remember isn't enough.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It sounds silly. It works.
- Mistakes like this are simple to make whilst your mind is on something else, so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a safety net, and keep checking the petrol pump.
- Less petrol means a thinner mixture, so stop as soon as you realise — while remembering that your next step is unchanged. It is still not to fire it up.
Petrol already in a diesel around Linthouse? Begin here
Then the order of things is short. Do not turn the ignition on, and don't start it. If you are still at the forecourt — Esso or anywhere else — ask the attendants to help you push the car clear of the petrol pump. Next, 0333 366 0103. We will ask what went in, about how much, and if it has been run.
Say so if it was AdBlue rather than petrol: it's a separate fault, with its own page for Linthouse, since AdBlue brings corrosion and deposits rather than lost protection.
What makes one Linthouse petrol in a diesel task cost more than the next
The four scenarios above are four separate jobs, so no single quote for this would be honest. The situation itself does most of the work of moving your cost. Where the vehicle is matters too, and whether a van can safely get to it, after the ratio of petrol to what your tank holds.
That is why our engineers ask three questions before costing instead of after: what was put in, how much, and if it has run. A range turns into a straight figure once those replies are in.
About Linthouse
Linthouse is a riverside suburban area in Glasgow City, situated near the River Clyde at an elevation of around 7 metres. Linthouse is located approximately 3.7 miles from Glasgow city centre and is close to nearby places such as Drumoyne, Shieldhall, and Govan. Linthouse has a population of around 3480 people and is predominantly composed of flat-type housing.
Linthouse and Glasgow City: where our fuel drain cover reaches
Linthouse sits in the G postcode area, and the teams that answer petrol in diesel call-outs there work the spots around it as well — Drumoyne, Shieldhall and Govan among them. The vehicle does not need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump around Linthouse, still?
In that case, you could not be in a better spot. Ring, and leave it turned off.