Schoolgreen: Put Petrol in a Diesel Car?
Never start your engine. While the fuel is still in the tank and the engine has not yet turned over, a tank drain is almost always all it needs — and that gets settled in the following few minutes, not by how much got in. Petrol in Diesel drains and cleans wrong-fuelled vehicles where they are, throughout Schoolgreen and the rest of Berkshire, on the forecourt, by the roadside or on a drive. Our team can tell you what the following stage is. Contact us — this comes before everything else.
Now what? Petrol in a diesel, step by step
- Feed a petrol motor diesel and it will typically fail to run at all, so the person stops there and so does the damage. Give a diesel petrol and the car starts, it ticks over, it drives off — all right for several miles. People have that backwards, which is the bit they get wrong about petrol in a diesel in particular. So do not crank it. And having started, don't rely on it: the fuel system is grinding while you drive.
- Diesel burns, and before it combusts it lubricates — your high-pressure pump, the injectors. Petrol handles only the burning. So leave the car's ignition alone too: turning it on is frequently enough to prime your system, and priming draws petrol from your tank into exactly those parts.
- Topping up clears nothing. It leaves you a bigger tank of the same blend, because a diesel fuel system won't handle petrol by percentage the way that advice suggests — so do not pour diesel on top to water down it. Grade is beside the point too: super unleaded is petrol.
- Remain where you are if you sensibly can. A motor that has not shifted is the simplest one to handle, and we would much rather come to an awkward spot than have it started. If you are pulled up on the verge on School Green, turn the hazards on and keep the car there.
- Before you phone, have your whereabouts. Anything closest to you with a name on it, plus a postcode beginning RG2 9 — that's what determines whether the technician shows up or circles.
- What got in, about how much, and whether the engine has run — the three facts shape the full visit. Phone 0333 366 0103 and tell us.
How far you travelled is what our engineers ask about, not how long the car has been parked — and this is why. Diesel has two tasks on its way through an engine: it combusts, and before burning it lubricates its high-pressure fuel pump and its injectors. Petrol does the first only. So a hurried fill on the drive in, the realisation coming close to eleven, and a diesel Volkswagen Golf parked at Earley since quarter past eight tells us those couple of miles were covered with your pump working on a fuel drained of most of its protection. Phone then leave the car right where it sits.
If you've put petrol in the diesel Skoda Octavia in Schoolgreen and you are now sat outside Lidl with a boot packed with shopping, ring us. Don't crank it once more to exit the bay. We will come to you, empty the tank, purge those fuel lines then put fresh diesel in so you can head home. A mile or so at gentle throttle uses hardly any of it, which is why those tend to be the simple cases.
What our technicians will want to know is if the run there was short and chilly, since that is where petrol is slowest to burn fully — and whatever does not burn can get past the rings then into the oil. Right up to the moment somebody drives it home, a diesel Nissan Qashqai parked in the car park outside Bell & Bottle holding a tank of petrol in it is an easy job. Nothing worsens whilst it waits, so park it there overnight and phone us in the morning.
Injection pressure is the thing being lost. Petrol thins diesel, and weaker fuel slips past the close-fitting parts that are meant to build that pressure, so the further a diesel Audi A3 drove, the less well it held. Happy on the way out and sluggish on the way back is how that run to Deardon Field went, then, and your tank is where to look. Stop somewhere sensible, switch off then call us.
What occurs next is the problem. Your engine at once sucks the petrol still waiting in your filter and the feed lines back round through the pump a second time, as emptying a tank does nothing about fuel that has already left it. Drain it then put clean diesel in, somebody sure of themselves will tell you — and that advice is only half right, because do it to a diesel Mercedes A-Class parked up, St Mary's Parish Church say, and the thing starts, which is what makes it sound sensible. Ring us instead. Our engineers flush the circuit and take your filter off where your vehicle has a workable one, and that's the difference between your car being fixed and your car simply starting.
Can petrol be drained out of a diesel at the forecourt?
Pumps are where the work often begins, and where a big portion of that finishes. We work on garage forecourts regularly, with the site's permission, and so if you are still at Esso that's usually where this drain takes place.
Before your engine has fired — the forecourt is the one place this is halted. The few seconds between reading your receipt and reaching for the keys decide how much needs cleaning. Anywhere other than a forecourt — a car park, a drive, a lay-by — the car was started and driven to get there, so fuel was drawn from the tank, through the filter and into the high-pressure pump. That means your lines and your filter require rinsing as well as your tank. It is not a calamity, and our technicians can still sort it out where the car stands.
Staff will generally help out pushing it clear of the petrol pump, which lets the next motorist get by. Welcome the offer. Four car lengths is not worth a start.
Service in Schoolgreen
Shinfield, Ryeish Green, Whitley Wood, Three Mile Cross, Arborfield — every one of them on the runs that bring us out to Schoolgreen itself, a residential suburb.
Not on the list? It tells you nothing. The places above are only the nearest few, and most places around Berkshire have a page of their own elsewhere on this site. Assuming is the mistake to skip, particularly on the border or somewhere your satnav goes wrong. Ring us and enquire.
The ground this page covers appears on our map. Your car never needs to come to us. We operate over all of it — kerbside, forecourts, driveways, car parks.
Broken down at the kerbside around Schoolgreen
The opportunity to pull in somewhere sensible doesn't fall to everyone. A normal call for us instead of a rare one: realised after setting off, landed along the verge beside Hyde End Road or in a lay-by with the hazard lights on.
Stay by your car when it's wise to be inside, yet clear of it when it is not. Every mile a diesel obliges you for on petrol drags that blend further into the fuel system — and oblige it often will, which is why your motor doesn't get restarted to limp somewhere handier. We'll bring our van to an inconvenient location without any bother, and for your car that is much better than driving on.
So you've driven it? Petrol in a diesel after a couple of miles
Here is where the M4 matters, under a mile out of Schoolgreen. It will usually take you onto it, and some way along, before you spot a thing. Then it's some smoke, an uneven idle and power falling away — not a clean stop. Wrongly fuelled diesels rarely give you one of those.
Never restart it to move it. Get off at the first safe junction then switch off. On a longer run — anything close to the under 50 miles to the closest city — take it the petrol has been through the filter, your pump and your injectors, and say so when you phone. It changes what our technicians bring.
All about Schoolgreen
Schoolgreen is a suburban area in Berkshire, situated on the riverside at an elevation of around 45 metres. Schoolgreen lies within the commuter belt, approximately 36 miles from London and 27 miles from Oxford, making it a popular residential location. Schoolgreen is characterised by its semi-detached housing and is surrounded by nearby places such as Shinfield, Ryeish Green, and Whitley Wood. Schoolgreen has a population of around 4005 residents.
The visit in Schoolgreen, step by step
- We ask first, quote after. What got in? How much? Has the engine run? Those responses change what the work actually is.
- Your tank is drained of everything.
- Our engineers rinse the fuel lines and clean your filter, and so what's remaining in the system is not what caused the trouble.
- Clean diesel goes in, and then your system gets primed.
- When it's started, we check it runs smoothly on fresh diesel.
The vehicle is then ready for you to drive away. We do everything wherever your car has come to a stop, which means it never needs to go to a workshop, and if it has been spotted quickly, it is very rare for there to be lasting damage.
Schoolgreen AdBlue removal is a different job
If what went in was AdBlue rather than petrol, the opening step is unchanged — never crank it — but this problem is not. Petrol does two things to diesel: dilutes it, and takes away the protection your fuel system depends on. AdBlue is urea dissolved in water, and in a diesel tank it causes corrosion and deposits instead.
Frequently the more serious of the two, AdBlue — and the detail sits on its own Schoolgreen page. Both are ours to handle.
What a petrol-in-diesel drain costs in Schoolgreen
Our technicians cannot put one figure on this page frankly, as this job isn't one job. What moves it:
- This is the big one: whether the engine has been run, or driven.
- Wrong fuel in, against what the tank holds — that proportion.
- Whether it was petrol or AdBlue.
- Where is it? And can a van get to it and work there safely?
The vehicle, the quantity, whether it has run — give us those and the answer comes back clear and not as a range. For your car at home that's going nowhere and isn't time-critical, is fine too.
Schoolgreen drivers ask us these about petrol in diesel
Fuel drains on a Schoolgreen petrol station forecourt
Plenty of what we do happens nowhere else. So yes. Tell us which one you are at when you phone and we'll tell you if our technicians can work there. With the owner's consent our technicians visit BP and the other forecourts nearby regularly.
Is there a sensible amount of petrol in a diesel?
Ratio decides it instead of litres — and more than either, whether your engine has run. An almost empty tank with five litres in it, against a full one with the same five: distinct scenarios, of course. Either way, the work needed comes down to one thing, which is whether the system has had that mixture drawn through it.
I drove the car after putting petrol in my diesel. Now what?
Stop safely. Off. Nothing after that. Driving is what takes the problem from that tank into the pump and injectors — but it is recoverable much more frequently than motorists assume, and the single most helpful thing you can do now isn't restart the car.
Will a fuel drain void my warranty?
No. Carried out properly, draining and cleaning is no modification at all, and the warranty from your manufacturer is untouched by it. An argument over a warranty is likelier to come from running a diesel on petrol — so leave it switched off.
Adding two-stroke oil, then driving home
Two-stroke oil solves a distinct issue, and an old one at that. Nothing it does puts back what petrol thinned. No. The pump still has to put up with it, as the tank still has petrol in it later on.
Main dealers and petrol in a diesel
You do not need one. The car is drained and cleaned wherever it is, with no need to take it to a dealership.
Still with the vehicle?
Switched off is how the car stays.
Turn it off somewhere safe and keep it off, if you have already driven it. Cold, stationary, going nowhere: that's the best position to be in. People fear this a lot more than they need to.
Throughout Berkshire and around Schoolgreen: on-site fuel draining, at home or on the forecourt or at the kerbside.