Put Petrol in a Diesel Car in Rhydyfelin? Don't Start It
Petrol in Diesel drains and cleans wrongly fuelled vehicles where they stand, on the forecourt, by the roadside or on a driveway, throughout Rhydyfelin and the remainder of Rhondda Cynon Taf. The first thing to do is not to turn on the engine. When the engine has not yet run and the petrol is still in your tank, a drain is nearly always all it takes, and the following few minutes settle that, not how much went in. Phone so our technicians shall show you what happens from here before you attempt any more.
What to do first about petrol in a diesel
- As you drive, the pump and the injectors wear down. That is why you never start the car, and why you do not depend on it once it has started. The thing about petrol in a diesel specifically — the bit most people get wrong — is that it drives off normally for the first mile or two. Diesel in a petrol engine normally can't run at all, which stops the person and stops the wear with them. This one lets you keep going.
- Two things, diesel: it burns, and on the way through it keeps that injection pump and injectors oiled. Petrol only does the one. That is why the car's ignition stays off as well — turn it on and you commonly prime that system, and that's petrol leaving your tank for precisely those components.
- Don't thin it. Diesel tipped on top takes out nothing, so all you have is more of what was already there, since percentage is not how a diesel fuel system accepts petrol. Super unleaded? Still petrol. The octane makes no difference.
- Wait where you are if you safely can. A motor that hasn't moved is the simplest one to handle, and we'd rather come to a difficult place than have it started. If you're stopped on the verge on Holly Street, switch those hazards on then keep the car there.
- Have your position ready before you ring. A postcode beginning CF37 5 and whatever is nearest to you with a sign on it is the difference between our van turning up and our van circling.
- Three details shape the whole visit: the stuff you put in, the rough quantity of it, and whether anything has been going since. The line is 0333 366 0103.
Quarter past eight. A fast fill on the trip in. Close to eleven it hits you, and by then the diesel Volkswagen Golf has waited outside Trefforest for three hours. Phone and keep the car where it stands. What is key is the trip in, as diesel both combusts and — before that — protects the pump and the injectors, but petrol only ever ignites. Those few miles worked the pump on a fluid robbed of most of its protection, and no quantity of sitting in a car park adds any of that back. Hence the thing we ask about miles instead of hours standing, and hence the request to leave the keys be until we turn up.
You set off at the end, once our engineers have fired it up and made sure it runs correctly on fresh diesel, with your system primed. Before that, in the car park outside Hawthorn Inn, the tainted fuel comes out of your tank, the fuel lines get rinsed and the filter comes off where your Ford Focus has a serviceable one. Everything starts with three questions when our technicians get to the car: what went in, how much of it, and whether it has been started since.
None of that is your engine failing. That's the part worth hearing, and it is why the ordinary Coed Craig-lwyd call ends better than it sounds: a diesel Mercedes C-Class drives out there without complaint, comes back with the power gone, the idle uneven and maybe a little smoke, and the cause is your fuel no longer acting like diesel. Diesel has to be viscous enough to seal the close-fitting parts it flows through; petrol weakens it; and a diesel injection system is hydraulic as much as chemical, needing the fuel to hold pressure rather than only to burn. So pressure that should build and stay built bleeds past clearances, delivery turns up poorer and later and less even than designed, and all of that stops once the fuel is put right.
Why so direct about leaving the keys alone? Since the pump is before the injectors, and a worn one sends whatever it loses onward with the fuel. Phone us. Leave the BMW 5 Series close to Rhydyfelin Methodist Church.
Switch off where you have stopped, and don't start it to find somewhere better — by Arthur's Gym or anywhere at all. Knocking, a lumpy idle, white smoke and a soft throttle are a misfuelled diesel Peugeot 208 telling you what's wrong.
On the forecourt: draining petrol from your diesel
It starts at a forecourt, mostly. Frequently the work wraps up on site too. We operate on station forecourts all the time, with the station's permission, so if you're still at Tesco that's generally where the drain gets done.
No place other than the forecourt can it be caught with your engine still cold. Anywhere else — a car park, a private drive, a lay-by — your car was fired up and moved to get there, which means fuel was pulled from that tank, through the filter then into the high-pressure pump. That's not a disaster, and our technicians can still deal with it where it sits. It does mean your lines and the fuel filter need flushing as well as that tank, and that's decided by the few seconds between seeing the receipt and reaching for the keys.
Away from the pump, the next motorist can get past — so yes, let the attendants help you move the vehicle. Worth doing. Firing it to shift four car lengths isn't.
Will our technicians reach your side of Rhydyfelin?
Being a residential suburb, Rhydyfelin has a frequent call, and the areas close by go with it on the same trip: Hawthorn and Treforest, Glyntaff and Upper Boat, Upper Church Village.
Not on this list? That tells you nothing. The names above are only the nearest few, and the majority of locations around Rhondda Cynon Taf have a page of their own elsewhere on our site. Close to the boundary, or anywhere the satnav struggles with? Ring us and check rather than guessing.
Look at our map for the ground covered here. Roadside, forecourt, drive, car park: every bit of that is territory our technicians work on, and none of it requires your vehicle to move to us.
Rhydyfelin: stranded wherever you pulled up
A chance to pull over somewhere safe does not fall to everybody. Hazards on at a lay-by somewhere, or pulled onto the verge on Elm Street as you noticed after setting off — our engineers take that call so often that it's the usual kind.
Safe where you are? Sit with it. Not safe? Move out and clear of it. Every mile a diesel obliges you for on petrol pulls that mix further into the system — and oblige it frequently will, which is why your engine does not get restarted to limp somewhere safer. Driving on does your car far more harm than our van coming out to a difficult place, and that is no problem for us.
Already driven it? Petrol in a diesel over a couple of miles
This is where the local M4 matters, under 5 miles from Rhydyfelin. A loss of power, a lumpy idle, smoke: those are the symptoms when they arrive, rather than a tidy stop — and a misfilled diesel will often take you onto it and some way along before anything seems wrong at all.
The first safe junction is the one to take. Switch off there, and leave the restarting alone. Presume the worst of that on a long trip. Anything approaching the under 10 miles to the closest city, and the mixture has been through your filter, through the pump, through your injectors. Tell us when you call. What our technicians bring alters.
Rhydyfelin itself
Rhydyfelin is a suburban area in Rhondda Cynon Taf, situated near the River Taff at an elevation of 64 metres. Rhydyfelin lies close to the nearby communities of Hawthorn, Treforest, and Glyntaff, and is approximately 9 miles from Cardiff. Rhydyfelin has a mix of housing types, with terraced housing being predominant in the area. Rhydyfelin is part of the wider Cardiff urban area, with the city centre easily accessible from the suburb.
What happens when our technicians arrive with you around Rhydyfelin
- Our technicians ask first, price after. What got in? How much? Has your engine run? Those replies alter what the work really is.
- The polluted mixture is drawn from your tank.
- Lines rinsed, filter cleared. Whatever is left later is not the thing that started the problem.
- Fresh diesel goes in, and then the fuel system gets bled.
- The motor is turned on and tested to make sure it runs properly on clean diesel.
Then it is ready to set off. All of this is done where the vehicle is, so it never needs to be taken to a garage, and when it has been noticed soon, lasting damage is very unusual.
Rhydyfelin AdBlue removal is a separate problem
Don't crank it: that opening instruction stands whether what was put in was AdBlue or petrol. What changes is this issue itself. The protection a fuel system relies on is taken away by petrol, which weakens your diesel. Urea in water, AdBlue, and in a diesel tank that causes corrosion and build-up.
Our technicians deal with both, and AdBlue removal in Rhydyfelin has its own page with the detail — including why it's usually the more serious of the two.
How much is a petrol-in-diesel fuel drain around Rhydyfelin?
Our technicians can't put one figure on this page honestly, since the job isn't one job. What moves it:
- Started? Driven? Either answer counts more than anything else on this list.
- How much of the wrong fuel went in, measured against how much the tank takes.
- Whether it is petrol or AdBlue.
- Access: the car's position, and whether working on it there is safe for a van.
Tell us what your vehicle is, how much got in, and if your motor has run. A clear answer comes back, not a range. Not time-critical, with your car at home and going nowhere? Then does the job.
Questions our technicians get about petrol in diesel around Rhydyfelin
At a petrol station in Rhydyfelin, can you do a fuel drain there?
A good part of this work takes place there, so yes. We work at Esso and the other forecourts around town routinely, with the site's agreement — tell us which one you are at when you call and we'll tell you whether our technicians can work there.
Is there a sensible quantity of petrol in a diesel?
Litres aren't the yardstick. Ratio is, and a lot more than either, it counts if anything has been run. What settles how much work is needed is if that mixture has been sucked through the fuel system — since although five litres in an almost empty tank is a different matter from five in a full one, either way that's the query.
I put petrol in my diesel and drove it. Now what?
Somewhere safe, then stop, then turn off and leave it off. Driving is what shifts the problem from your tank into your pump and injectors — but it's fixable much more commonly than drivers expect, and the single most helpful thing you can do now isn't restart it.
Fuel drains and manufacturer warranties
A drain and flush carried out properly isn't an alteration and does not invalidate a manufacturer's warranty. Another good reason to leave it turned off: running a diesel on petrol is the thing more likely to cause an argument with one.
Adding two-stroke oil, then driving home
No. It belongs to a different problem from a different era, and petrol has diluted something no oil of that kind replaces. Petrol stays in that tank later on, whatever else goes in, and your pump gets no reprieve from it.
Does petrol in a diesel have to go to a main dealer?
No. We drain and clean your car wherever it is, so there is no need to bring it to a main dealer.
Waiting next to it?
Do not switch it on again.
Already driven it? Then stop somewhere sensible, switch off, and let the vehicle stay that way. Cold and stationary, a car is in the best position available — and motorists fear this much more than the recovery rate warrants.
Draining misfilled motors, Rhydyfelin and the rest of Rhondda Cynon Taf, wherever they are. Kerbside. Forecourt. Home.