--- title: Drain Petrol From a Diesel Car — Parc Erissey canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/parc-erissey-cornwall/ location: Parc Erissey county: Cornwall latitude: 50.255410 longitude: -5.234990 service: Petrol in a Diesel Car updated: 2026-10-24 --- # Parc Erissey: Put Petrol in a Diesel Car? With your tank still carrying the petrol and the engine not yet run, almost every job requires only a drain, so leave the engine off. That result is determined in the minutes right after the fill-up, and not by the amount that went in. Across Parc Erissey and the rest of Cornwall, Petrol in Diesel drains the car and cleans it where it sits, whether at a roadside, on a private drive or at a forecourt. Ring us before everything else begins, so you will hear what comes from there. ## What next? Petrol in a diesel, step by step - Feed a petrol engine diesel and it will generally not run at all, and so the person stops there and so does the harm. Feed a diesel petrol and the car starts, it idles, it drives off — fine enough for a few miles. Motorists have that reversed, which is the part they get wrong about petrol in a diesel especially. So do not fire it up. And having started, never rely on it: the fuel system is wearing down while you drive. - Two things, diesel: it burns, and on the way through it keeps that high-pressure pump and injectors oiled. Petrol only handles the one. That is why the ignition is left off as well — switch it on and you frequently prime the system, and that is petrol exiting that tank for precisely those components. - Never weaken it. Diesel added on top gets rid of nothing, so all you get is more of what was already there, since percentage is not how a diesel fuel system copes with petrol. Super unleaded? Still petrol. The grade makes no difference. - We'd sooner travel to a difficult location than have it started — so if you sensibly can, stay put. Nothing is easier to handle than a car that hasn't moved. On the verge on New Portreath Road, that means hazards on then leave the car. - Get your location ready before you dial. A postcode beginning TR16 4 and whatever is closest to you with a name on it is the difference between a van turning up and the van circling. - What went in, about how much, plus whether the car has run — those three details settle the full visit. Ring 0333 366 0103 then tell us. Don't drive it home. The commute has already pushed a real volume of petrol-thinned diesel through the high-pressure fuel pump of that Volkswagen Golf, and the drive back would about double it for no purpose at all. Call us from the platform if that's handier. Our technicians never need you hovering over the vehicle at Redruth whilst our technicians get on, and we'd very much rather speak to you tonight than discover on Monday. ## Draining petrol from your diesel on a forecourt Most of this job starts at a forecourt, so a good chunk of that ends up done there. Still at Tesco? Then that is generally where it takes place. Garage forecourts are normal for us, with the agreement of the station. No place but a forecourt can it be spotted with your motor still cold. The few seconds between seeing your receipt and reaching for the keys settle how much needs rinsing. Everywhere other than the forecourt — a car park, a driveway, a lay-by — the vehicle was fired up and moved to get there, so fuel was pulled from the tank, through the fuel filter and into your high-pressure pump. That means the fuel lines and the filter require rinsing as well as your tank. It is not a disaster, and our engineers can still sort it out where your car is. Attendants will generally help out pushing it clear of the petrol pump, which lets the next driver get by. Accept the offer. Four vehicle lengths is not worth a start. ## Coverage in Parc Erissey North Country, Gilberts Coombe, Laity Moor, Treleigh, Cambrose — all of them on the rounds that carry us across to Parc Erissey too, a coastal area. We still come. The places above are only the closest neighbours, and a page exists for most locations across Cornwall, and so an absence from the list isn't an absence from our coverage. Contact us to check rather than assuming, particularly where you are on a border or somewhere a satnav gets wrong. The map marks the area this page spans. Kerbside, forecourt, drive, car park: all of it is ground our technicians cover, and none of that needs your vehicle to travel to us. Put diesel in a petrol car and generally it won't run, so the motorist stops there and the harm stops with them. Reverse it — petrol into a diesel — and the thing fires up, ticks over and drives off as though nothing had happened, while your high-pressure pump works without the protection the fuel is supposed to be giving. That is the snag, and it is why your diesel Peugeot 308 will have seemed perfectly ordinary coming back from Treleigh Community Primary School. They all do. From the driver's seat there is nothing to warn you about, so nothing tells you. Ring us with about how far you drove, and how hard; the second answer matters more than the first. ## Roadside breakdowns across Parc Erissey Not everyone has the opportunity to pull in somewhere sensible. Set off, then realised? Finished up along the verge of Bassett Road, or sat in some lay-by with the hazard lights on? That is a routine call here. Not an odd one. Whether you stay beside the motor or stand away from it depends on if staying there seems wise. It will frequently oblige. A diesel running on petrol limps along quite willingly, and that is the problem: start it up to get to somewhere safer and that mix goes further into your fuel system with every mile driven. A technician coming to an inconvenient location is no trouble for us, and it's a lot better for the vehicle than driving on. What our technicians will ask about is if that drive there was brief and chilly, because that is where petrol is least able to burn properly — and what doesn't burn can work past the rings and into the sump. Right up to the moment somebody takes it home, a diesel Nissan Qashqai parked in the car park outside Treleigh Arms carrying a tank full of petrol in it is an easy job. Nothing deteriorates while it sits, so park the car there overnight and call us first thing. ## Driven it already? Stop, then see this Here is where the local M5 comes in — over 50 miles away from Parc Erissey. A misfilled diesel will often get you onto it and some distance along before anything feels wrong, while the symptoms when they come are usually a loss of power, an uneven idle and smoke instead of a clean stop. The first sensible exit is the one to take. Turn off there, and leave the restarting alone. It affects what our technicians bring, and so mention it when you call: on a longer run — anything near the under 10 miles to the closest city — take it the mixture has been through your filter, the pump and the fuel injectors. ## All about Parc Erissey Parc Erissey is a coastal locality in Cornwall, situated near the city of Truro and overlooking the surrounding countryside from an elevation of around 60 metres. Parc Erissey lies within a region of dispersed settlements and rural landscapes, including nearby North Country, Gilberts Coombe, and Laity Moor. Parc Erissey is characterised by its predominantly detached housing stock, reflecting its status as a residential area with a population of around 503 people. ## What comes next when our technicians arrive with you around Parc Erissey - Our engineers check what went in, how much, and if your motor has run. The answers change the work, which is why our engineers ask before giving a price. - Your tank gets cleared completely. - What is left in the system shouldn't be what started the problem, so the lines get rinsed and your filter cleared. - Your system gets bled, on fresh diesel. - The engine is fired up and checked to confirm it runs smoothly on new diesel. That has it ready to set off. Lasting damage is very rare when it has been spotted quickly, and as all of it is done where the car is, it never has to be taken to a workshop. ## AdBlue in a diesel tank in Parc Erissey is a distinct job AdBlue rather than petrol? Then the opening step is unchanged — the engine remains off — while this problem under it's a distinct one altogether. Weakened diesel, and no lubrication left for your fuel system that relies on it. That's petrol. AdBlue is urea dissolved in water, and in a diesel tank it leads to corrosion and deposits instead. Often the more serious of the two, AdBlue — and the detail sits on its own Parc Erissey page. Both are ours to deal with. Strange places are where this occurs most, and the reason is mechanical instead of slapdash: the slimmer petrol nozzle goes into a modern diesel filler neck with almost no resistance at all. Filled up close to Redruth Old Cornwall Society Museum without thinking, in a diesel BMW 5 Series you have had for two days? Call us where you are. Hire and courtesy cars often get driven further before anyone notices, and mileage is what settles how much petrol reaches the fuel injectors. ## What a petrol-in-diesel fuel drain costs around Parc Erissey What changes the price is listed below, as this job is not one job and our engineers can't honestly put a single number on this page. - Whether your engine has been started or driven. This is the big one. - The tank's capacity, set against how much of the wrong fuel got into it. - Which was put in: unleaded or AdBlue. - Where the car is, and whether our van can sensibly reach and work on it. A clear answer rather than a range is what you get for telling us three things: your car, the amount, and whether it has run. Vehicle at home, going nowhere, nothing urgent about it — is ideal for that. It got a couple of streets and stopped. The throttle went soft, the idle turned lumpy, and your diesel Vauxhall Astra is now resting by St Stephen. That sluggishness is your fuel failing to build pressure fully rather than the engine giving up — and because there is no dashboard light for it, motors in that position typically get driven again before somebody rings. Please don't. Turn it off then phone us. ## Parc Erissey motorists ask us these about petrol in diesel ## Fuel drains on a Parc Erissey petrol station forecourt A good part of this work happens there, so yes. Our technicians visit Texaco and the other forecourts locally regularly, with the site's agreement — tell us which one you are at when you call and we will tell you if our technicians can work there. ## How much petrol in a diesel is too much? Whether your motor has run counts much more, though the proportion counts too, rather than the litres. Five litres into an almost dry tank is not five into a full one, no. But both land on the same query in the end: has that mixture been drawn right through, or has it not? ## I drove the vehicle after putting petrol in my diesel. What next? Somewhere safe, then stop, then turn off and leave it off. Driving takes the issue along — out of the tank, into the pump and injectors. People fear it a good deal more than the recovery rate warrants, mind. The one genuinely valuable thing left to you is not restarting it. ## Is a fuel drain going to void my warranty? A drain and flush carried out correctly is not a modification and doesn't cancel a manufacturer's warranty. Another good reason to leave it turned off: running a diesel on petrol is the thing more likely to cause a disagreement with one. ## Adding two-stroke oil, then driving home Two-stroke oil solves a distinct fault, and an old one at that. Nothing it does puts back what petrol diluted. No. Petrol stays in that tank later on, whatever else goes in, and the pump gets no break from it. ## Does petrol in a diesel have to go to a main dealer? Wherever the vehicle is, our technicians drain and clean it there, so a drive to the main dealer doesn't come into it. ## Still with the car? Turned off is how it stays. Driven it already? Then somewhere safe, stop, switch off, and no restarting the vehicle afterwards. Cold, parked, going nowhere: that is the best place to be in. Drivers fear this a lot more than they need to. Emptying wrongly fuelled motors, Parc Erissey and the rest of Cornwall, wherever they are. Roadside. Forecourt. Home.