--- title: Houndsmoor: Petrol in a Diesel Car, Explained canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/houndsmoor-somerset/ location: Houndsmoor county: Somerset latitude: 51.021480 longitude: -3.247190 service: Petrol in a Diesel Car updated: 2026-10-23 --- # Petrol in a Diesel Car in Houndsmoor: How Worried Should You Be? Unstarted? Then less anxious than you likely feel. Petrol resting in a diesel tank does nothing to your motor till something draws it through the fuel system — the ignition priming your pump, the starter, or the drive itself. So the truthful answer to the first question anyone around Houndsmoor asks, "have I wrecked it?", is normally no. Keep it like that: leave your motor off and phone Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and the way to make sure you never do it again. ## Inside your engine: what petrol in a diesel does Diesel has two jobs on its way through an engine. It combusts, and before it combusts it lubricates. The high-pressure fuel pump and the fuel injectors are made to very fine tolerances, and your diesel passing through them is what keeps those surfaces from wearing against one another. Poorly at the first, not at all at the second: that is petrol. A pump running on a petrol mixture is wearing itself out, because petrol is runnier than diesel and strips out the lubrication the fuel system depends on. Petrol is also made to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that is where any knocking comes. Put those together and the shape of the trouble is clear. The harm is done by movement, not by contact. Where the petrol is only in the tank, it is a problem of fuel, nothing more. Whatever a worn pump sheds travels on, borne by your fuel, into your injectors downstream, which is why a pump that has worked on the petrol is where a mechanical fault begins. ## Four scenarios we see in Houndsmoor: how serious is petrol in a diesel? The best case there can be: filled up, not once started. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it's cleared and cleaned on the spot, and nothing more is needed. The ignition switched on, or a short start. With the fuel system primed, your lines and filter already hold petrol that has come from that tank. Drain, flush, see to the fuel filter: still usually simple. Driven a couple of miles. Now your pump has spent those miles labouring on thinned fuel. Mileage is only half of that; how hard it was driven counts just as much. Either way the work includes that tank, the fuel lines, the fuel filter and fresh fuel through the entire circuit. A school run to Milverton Community Primary School and Pre-School is one thing. A run as far as Exeter, under 25 miles away, is a very different task. So is any miles on the M5, under 5 miles from Houndsmoor, where the engine has been working hard the whole time. Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Whether it's the verge on Houndsmoor Lane, a lay-by or a side road, stop there and leave it. Lasting damage is very unusual when a vehicle is stopped early, and the drain and flush that still go first take care of it. ## Myths Houndsmoor people hear about petrol in a diesel False: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a fuller tank of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that advice supposes. If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." Smaller parts and higher pressure are how a newer diesel runs its fuel, and that makes the lubrication matter more, not less. Myth: "If it starts and drives, there's no damage done." This is the one that fools drivers. A petrol motor fed diesel generally will not run, so the motorist stops and the damage stops with them. While your pump grinds, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Fine and running are not the same at all. Myth: "Add some two-stroke oil and drive the car home." It's an old fix for a different problem. The petrol is still in your tank afterwards, and whatever it has diluted is not put back. Myth: "Drain your tank yourself and you're sorted." Once the engine has run, some of the petrol is no longer inside your tank: it's in your filter and the lines, and it goes straight back through your pump on your next start. Clearing petrol into a can by the kerbside is also really risky. ## How does petrol in a diesel occur? It is rarely carelessness, and nobody does it on purpose. A diesel nozzle generally will not fit a petrol motor, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and only in one direction. When habit and your car stop matching, it occurs. A vehicle that's new to you — hired, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Racing for a train at Taunton and fuelling up en route. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver used to petrol: precisely when it happens. With rain, a call arriving, or children to deal with, your hand just does what it has always done. ## Next time you fill up in Houndsmoor: preventing petrol in a diesel - Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is only a clue. - The first fill in an unfamiliar motor is the time to check your filler flap — on it, or on the cap, many motors state which fuel they take. - Mark the key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember. - Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, yes, yet it does the trick. - Put your phone away. This is an easy mistake to make whilst you are thinking about something else. - Add-on devices are available for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label. - Stop the moment you notice. Less petrol in that tank means a weaker mixture. It does not change what to do next, which is still not to crank it. ## Already put petrol in a diesel around Houndsmoor? Then the order of things is brief. Do not start the car, and don't turn your ignition on. The staff at the forecourt — whether at Esso itself or wherever you filled up — will normally help roll it away from the petrol pump if you ask. Then ring 0333 366 0103 and tell us what went in, roughly how much, and whether it has run. AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate issue — Houndsmoor has a page all for it. ## What makes one Houndsmoor petrol in a diesel task cost more than the next There's no honest single price for this, because the four situations above are four separate jobs. Chiefly, the cost shifts with which one you're in. Next it's the share — how much petrol was put in against how much your tank holds — and after that where the car is and whether our van can get to it safely. Ahead of any quote, not after, we ask three queries: your fuel that was put in, the volume, and if it has run. That is why. With those replies, you get a straight figure rather than a range. ## About Houndsmoor and its setting Houndsmoor is a small suburban area situated on the riverside in Somerset, with a mix of detached housing and a population of around 740 residents. Houndsmoor sits at an elevation of 78 metres, near the villages of Milverton and Weekmoor, and is located approximately 24 miles from Exeter. Houndsmoor is part of a wider area that includes nearby Preston Bowyer, and is connected to the surrounding countryside by a network of roads and footpaths. Houndsmoor is also within commuting distance of larger cities, being around 139 miles from London. ## Across Somerset and in Houndsmoor: fuel drain cover The vans answering petrol in diesel jobs around Houndsmoor, in the TA postcode area, equally work the places near it, Milverton, Weekmoor and Preston Bowyer included. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain. ## Still at the pump in Houndsmoor? Then, you couldn't be in a better spot. Call, and leave it switched off.