How Worried Should You Be? Petrol in a Diesel Car in Catcott
Provided it hasn't been started, worry less than you probably are. Petrol resting in a diesel tank does nothing to the engine until something draws it through the fuel system — your ignition priming the pump, your starter, or driving on its own. So the truthful answer to the first query everyone in Catcott asks, "have I wrecked it?", is generally no. Petrol in Diesel is who to call, with the motor left off, so it remains that way. Below, you will find what petrol actually does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
The motor and petrol in a diesel: what happens
Passing through an engine, diesel is doing two things at the same time. Before it ignites, it protects — and then it combusts. The high-pressure fuel pump and the injectors are built to very fine tolerances, and the diesel passing through them is what stops those surfaces from wearing against one another.
Of these two tasks, petrol handles the first poorly and the second not at all. It's thinner than diesel and takes away the protection your fuel system depends 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 reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Combined, those leave the shape of the trouble plain. Not contact but movement is what causes the damage. Where the petrol is only in your tank, it's a fault of fuel, nothing more. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors beyond it.
Four scenarios our technicians see around Catcott: how bad is petrol in a diesel?
Fuelled, and never started: nothing beats it. That petrol is in your tank and just your tank, and the task is a drain and a flush where the car sits. This is the one scenario that can only truly happen at a forecourt, because anywhere else the car has been driven to get there.
Started for a moment, or only the ignition on. Petrol has left that tank and reached the fuel filter and the fuel lines, since the system has been bled. Drain, flush, see to your filter: still usually simple.
Your pump now spent a couple of miles on diluted fuel — that is what driving the vehicle meant. The work is your tank, your lines, your filter and clean fuel through the entire circuit, and how hard your car was driven counts as much as how far. On the school run to Catcott Primary School, the miles is short. A run as far as Wells, under 15 miles away, is a very different task. So is any miles on the M5, under 5 miles from Catcott, where your engine has been labouring hard throughout.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. The engine is telling you your fuel is no longer behaving like diesel. Pull up on the spot — on the verge on Church Way, at the kerb, down a side road — and do not move it again. Permanent damage is very unusual when a vehicle is pulled over quickly, and the fuel drain and flush-through that still come first sort it out.
Petrol in a diesel myths Catcott people hear
False: topping up to full with diesel makes it fine. It doesn't. A bigger tank of the same mix is all you get, since topping up takes out nothing. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance assumes.
Myth: a current diesel copes with a bit of petrol. Rather, the reverse. At higher pressure, through more precise parts: that is how a current diesel handles its fuel, so the protection counts more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no damage done." The driver of a petrol engine fed diesel usually has no choice but to stop, since it will not run, and the damage stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump wears. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate fault. The petrol is still inside that tank afterwards, and whatever it has diluted is not put back.
Myth: "Drain that tank yourself and you're sorted." Once the motor has run, some of that petrol is no longer inside the tank: it's in the fuel filter and the lines, and it goes right back through your pump at the next start. It is also genuinely hazardous to drain petrol into a can at the kerbside.
How does petrol in a diesel occur?
It is seldom carelessness, and no one does it on purpose. A diesel nozzle mostly won't fit a petrol motor, yet the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error straightforward, and just in that direction.
It happens when routine and the car stop matching. Courtesy car, hire car, or a car that's brand new. Two motors on one driveway, one petrol, one diesel. Your usual forecourt, its pumps now in a different order. Fuelling up in a rush en route to Bridgwater, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. Throw in a back seat full of children, a phone call or rain, and habit wins.
Catcott people: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is just a clue.
- Plenty of motors state the fuel inside the filler flap or on the cap, and so check it on your first fill in a vehicle you don't know.
- One of each in the house? Mark your key to your diesel — a coloured fob, a sticker — because meaning to remember is not enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so put your phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop checking the pump.
- Noticing it halfway? Stop at once. A weaker blend results from less petrol inside your tank, but your next step stays the same: do not start it.
Petrol already in a diesel around Catcott? Start here
In that case, there is only a short order of things. Starting it is out, and so is switching on the ignition. Still at the forecourt, at Murco or anywhere else? Ask the attendants to help you roll the vehicle clear of the pump. Then ring 0333 366 0103 and tell us what was put in, roughly how much, and whether it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate fault — Catcott has a page just for it.
What makes one Catcott petrol in a diesel task cost more than the next
There's no fair single quote for this, since the four situations above are four separate jobs. Mostly, your cost moves with which situation you are in. The share counts next, meaning how much of the tank is petrol, and then the position of the vehicle and whether reaching it is safe for a van.
Three questions come first, before quoting, rather than after — what went in, how much, has it run — and this is the reason. A range turns into a straight figure once those answers are in.
About Catcott, for a moment
Catcott is a small village in inland Somerset, situated near the villages of Edington, Chilton Polden, and Shapwick. Catcott sits at an elevation of 42 metres, approximately 10 miles from the city of Wells. Catcott has a population of around 542 people, predominantly living in detached houses. Catcott is located about 120 miles west of London, in the South West region of England.
Across Somerset and around Catcott: fuel drain cover
Edington, Chilton Polden and Shapwick are among the spots around Catcott that the same teams work, answering petrol in diesel calls across Catcott's TA postcode area. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places we drain.
At the petrol pump around Catcott, still?
The best place there is, then — that's where you are. Keep it off. Phone.