St Woolos: Put Petrol in a Diesel Car?
With the tank still carrying the petrol and your engine not yet run, nearly every job needs only a drain, so keep the engine off. That outcome is decided in the minutes right after the fill-up, rather than by the amount that went in. Across St Woolos and the rest of Newport, Petrol in Diesel drains the vehicle and cleans it where it sits, whether by a roadside, on a private drive or at a forecourt. Our team can tell you what the next part will be. Phone — that goes before all else.
Petrol in a diesel: what to do next
- Don't fire it up — and never trust it if it starts. Here is the part drivers have wrong about petrol in a diesel specifically. A petrol engine fed diesel generally just won't run, so the driver stops and the harm stops with them. A diesel filled with petrol generally starts, ticks over and pulls away without complaint for a few miles. It's not okay. It is wearing out your fuel system as you drive.
- Two tasks, diesel: it ignites, and on the way through it keeps that high-pressure pump and injectors lubricated. Petrol only does the one. Which is why the car's ignition is left off too — turn it on and you frequently prime your system, and that's petrol exiting that tank for exactly those parts.
- Do not pour diesel on top to thin it. A diesel fuel system won't handle petrol by percentage as that advice assumes, and topping up removes nothing — it simply hands you a larger tank of the same mix. The grade makes no difference either: super unleaded is still petrol.
- We'd much rather drive to an awkward spot than have it started — so if you safely can, stay put. Nothing is simpler to handle than a vehicle that has not moved. On the verge on Dewsland Park Road, that means hazards on and leave the car.
- Get your location ready before you ring. A postcode beginning NP20 4 and whatever is nearest to you with a name on it is the difference between the van showing up and the van circling.
- What was put in, approximately how much, and also if the motor has fired — these three facts determine the whole visit. Phone 0333 366 0103 and tell us.
Don't drive it home. The journey in has already pushed a real load of petrol-thinned diesel through the high-pressure fuel pump of that Volkswagen Golf, and the drive back would about double it for no gain at all. Ring us from the platform if that's easier. Our technicians do not need you hovering over your car at Newport (South Wales) while we get it done, and we would very much rather talk to you tonight than discover on Monday.
A diesel pump meters fuel to demand, and a hurried morning dash asks for plenty — so three miles in your BMW 3 Series sounds like nothing and isn't. Twenty to nine at the gates of the local primary school, running late, a receipt in your hand showing unleaded: hazards on, ignition off, ring us.
Pull in somewhere safe, turn off and call us. Normal on the way out to Clifton Park, sluggish on the way back? Then look at the tank. Petrol thins diesel; weaker fuel slips past the precision parts that build injection pressure; and the further the diesel Ford Focus drove, the less of that pressure it held.
Off the forecourt, receipt read, a couple of hundred yards, left near 1839 Chartist Route Marker. For a diesel Mercedes C-Class whose motor has turned, that's about the best version there is. Call us, then let it stand with the ignition alone. Short assists, really — but a start is a start and a drive is a drive, and the filter has had diluted fuel through it, and so has your pump. Which is why the fuel lines get cleaned and not just your tank emptied.
Drain it then put clean diesel in — that is the advice you will get, usually from someone sure of themselves, and it's half true. Do exactly that to a diesel Citroen C3 close to Chartist Burial Site and it would start, which is what makes the tip sound reasonable. What takes place next is the trouble: your engine immediately draws the petrol still resting in the fuel filter and the feed lines straight back through your pump, as emptying a tank does nothing about fuel that has already left it. Phone us instead. Our technicians flush the circuit and take the fuel filter off where your vehicle has a working one, which is the difference between your car being fixed and your car simply starting.
At a forecourt: removing petrol from your diesel
Forecourts are where this work often begins, and where a large chunk of that ends. Our technicians work on garage forecourts regularly, with the station's permission, so if you're still at Asda that is usually where this drain takes place.
Nowhere other than a garage can the mistake be stopped with the engine still unrun. Fuel pulled out of your tank and through your filter, right to the high-pressure pump, is what happens when the motor is started and the vehicle is driven to where it is now: the car park, the driveway or the lay-by, everywhere other than the forecourt. So the flush includes your filter and the lines together with the tank. That's still not a disaster, and our engineers sort it out where your car is. What settles it is whether the ignition was turned in the seconds after the till receipt was read.
The attendants will normally offer to roll the vehicle out from the pump so the next customer can get past. That is worth doing. Four car lengths is not worth the risk.
Do our technicians serve your end of St Woolos?
As a residential suburb, St Woolos sees a steady visit, and the places round about go with it on the same trip: Baneswell and Clytha Park, Stow Park and Newport, Gold Tops.
Not on that list? That tells you nothing. The names above are simply the closest few, and the majority of towns in Newport have a page of their own elsewhere on the site. Assuming is the habit to avoid, especially on the boundary or anywhere a satnav fails. Phone and ask.
Use the map for the ground shown on this page. Our technicians work by the road, on forecourts, on driveways and at car parks across all of it, and the car does not need to move to us.
Stranded at the roadside near St Woolos
Not everyone has a safe place to pull in. If you worked it out after setting off and finished up by the verge of Friars Crescent, or in a lay-by somewhere with the hazards on, that's a common call for us instead of an odd one.
Out of the motor while it's not sensible to sit in it, with it if it is. Every mile a diesel obliges you for on petrol drags that mix further into the system — and oblige it usually will, which is why the motor does not get restarted to limp somewhere safer. Our van coming to an inconvenient spot is no problem for us, and it is far better for your car than carrying on.
So you've driven it? Petrol in a diesel over a few miles
This is where your M4 matters, under 3 miles from St Woolos. Lost power, an uneven idle, some smoke: those are the symptoms when they appear, rather than a neat stop — and a misfuelled diesel will usually get you onto it and some way along before anything feels wrong at all.
Take the first junction that's sensible, pull up there, and do not restart it to move it. Presume the worst of that on a long run. Anything close to the under a mile to the closest city, and the mixture has been through the fuel filter, through the pump, through your injectors. Tell us when you ring. What we bring differs.
A little about St Woolos
St Woolos is a suburban area in Newport, situated near the coast of Wales, with St Woolos being close to the city centre and other nearby places like Baneswell and Clytha Park. St Woolos has a mix of housing types, but is predominantly characterised by terraced homes. St Woolos sits at an elevation of 59 metres, looking out over the surrounding area.
When we arrive with you in St Woolos: what happens
- Our technicians ask first, price after. What went in? How much? Has the motor run? Those responses change what the work really is.
- The tank gets cleared of it.
- We rinse the fuel lines and clear the filter, so what is remaining in your system is not what started the trouble.
- Bleeding your system follows, once new diesel is in.
- Your engine is fired up and tested to make sure it runs smoothly on clean diesel.
The vehicle is then ready for you to pull away. Everything is done where the car is, so it never needs to go to a workshop, and when it has been spotted soon, lasting damage is very unusual.
A separate job: AdBlue in a diesel tank around St Woolos
Do not crank it: that opening step applies whether what went in was AdBlue or petrol. What differs is this fault itself. Diluted diesel, and no protection left for the fuel system that relies on it. That's petrol. Rust and deposits are what a diesel tank ends up with instead, because AdBlue is urea dissolved in water.
Both are ours. There's a separate St Woolos page for AdBlue removal, with the full story on it — including the reasons it frequently turns out to be the worse of the two.
How much is a petrol-in-diesel fuel drain around St Woolos?
Our technicians can't put one figure on this page truthfully, because this job isn't one job. What changes it:
- This is the big one: whether the engine has been started, or driven.
- Wrong fuel in, against what your tank holds — that proportion.
- AdBlue or unleaded, whichever went in.
- Where is it? And can a van reach it and work there sensibly?
A firm answer instead of a range is what you get for telling us three things: your car, the quantity, and whether it has run. For the vehicle at home that's going nowhere and isn't time-critical, is fine too.
Petrol in diesel: everyday questions in St Woolos
I'm on a forecourt in St Woolos. Can you drain the car on the spot?
Yes — forecourts are where a large part of this happens. Tell us which one you're at when you call and we'll tell you whether our technicians can work there. With the site's consent we attend Tesco and the other forecourts locally routinely.
How much petrol in a diesel is too much?
It hinges on the ratio instead of the litres, and a lot more on whether the engine has run. A nearly empty tank with five litres in it, against a full one with the same five: distinct scenarios, of course. Either way, the work required comes down to one thing, which is whether your fuel system has had that mix drawn through it.
I put petrol in my diesel and drove the vehicle. What next?
Stop sensibly. Off. Nothing after that. It is salvageable far more commonly than people fear, even though driving is what takes the trouble from your tank into your pump and injectors — 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 correctly is not a modification and does not invalidate a manufacturer's warranty. Another reason to leave it turned off: running a diesel on petrol is the thing more likely to cause a dispute with one.
Adding two-stroke oil, then driving home
What petrol has thinned is not restored by two-stroke oil, which is an old fix for a different issue. So no. The pump still has to put up with it, because the tank still has petrol in it later.
Main dealers and petrol in a diesel
Wherever your car is, our engineers drain and flush it there, so a drive to the main dealer doesn't come into it.
Standing next to it?
Your engine stays off.
If you have already driven the vehicle, stop somewhere safe, switch it off then leave it off. A parked, cold motor is the best position to be in, and this is recoverable from a lot more commonly than motorists fear.
Call-out fuel draining around St Woolos and throughout Newport — at the roadside, on the forecourt or at home.