Westminster: Put Petrol in a Diesel Car?
If you have not started the engine yet, do not. A drain and nothing more is nearly always what a motor requires while the fuel is still sitting in that tank and the motor has not turned over, which is why it's the following few minutes that matter, not how much got in. Petrol in Diesel comes to the car wherever it has come to rest in Westminster or the remainder of Greater London, on the forecourt, at the roadside or on a private drive, and drains and cleans it there. A single ring to us is plenty: our team will tell you what comes after this. Try that first.
Your next five steps: petrol in a diesel
- Don't fire it up. Fired up all the same? Then don't believe it. Diesel in a petrol vehicle usually won't run, and so the driver stops and the harm halts with them. Petrol in a diesel? It starts. It idles. It moves off fine, for a couple of miles. People get that muddled. It isn't fine — that fuel system is wearing down every mile you do.
- Leave the car's ignition off also. Diesel has two tasks: it combusts, and before it combusts it greases that injection pump and its injectors. Petrol does the first but not the second. Turning your ignition on is often sufficient to prime the system, which carries that petrol out of that tank then into precisely those components.
- Never weaken it. Diesel tipped on top clears nothing, and 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? Simply petrol. The octane makes no difference.
- Wait where you are if you safely can. A car that hasn't moved is the simplest one to deal with, and our team would much rather travel to an awkward spot than have it started. If you are pulled up on the verge on Saint Margaret Street, turn those hazards on then keep it there.
- Know where you are before calling. A postcode that starts SW1A 2, and the name of whatever is nearest to you. Otherwise our van circles rather than arriving.
- Three replies settle the whole job: the liquid you poured in, the approximate measure involved, plus whether anything has been going since. Our number is 0333 366 0103.
Can petrol be taken from your diesel at the forecourt?
Plenty of this work starts at a forecourt, so a big portion of it gets finished at one. Our technicians work on petrol station forecourts routinely, with the site's agreement, and so if you're still at BP that is typically where this drain happens.
Before the motor has fired — the forecourt is the one place this ends up stopped. Fuel drawn out of the tank and through the fuel filter, right to the high-pressure pump, is what happens when the engine is fired up and your car is moved to where it is now: the car park, the driveway or the lay-by, anywhere other than the forecourt. So the flush includes the filter and the fuel lines as well as that tank. That's still not a catastrophe, and our engineers deal with it where the vehicle sits. What decides it is whether the ignition was reached for in the seconds after the receipt was read.
Wheel the vehicle out of the way if the staff volunteer, and they normally will. The next motorist gets by the petrol pump, and that is worth doing. Starting the car over four car lengths? Not a chance.
Can our engineers cover your part of Westminster?
Westminster is a cathedral city, and we head out to it and to the villages around it on the usual trips: Whitehall, Charing Cross, Lambeth, Millbank and Victoria.
If yours isn't on that list it does not mean we do not come — there are separate pages for the majority of locations around Greater London, and the ones listed above are merely the nearest neighbours. Contact us to ask instead of presuming, above all when you're on a boundary or anywhere your satnav gets wrong.
See the map for the patch covered here. The vehicle never needs to come to us. We work throughout the lot — kerbside, forecourts, driveways, car parks.
Westminster: stranded wherever you stopped
A chance to pull over somewhere safe doesn't come to everybody. Hazards flashing in a lay-by somewhere, or pulled onto the verge of Parliament Street because you realised after setting off — we take that call regularly enough that it's the normal kind.
Whether you sit beside the car or step away from it hangs on if staying in it seems wise. Every mile a diesel obliges you for on petrol draws the mixture further into the system — and oblige it frequently will, which is why the engine doesn't get restarted to limp somewhere handier. However inconvenient the location, it's no problem for us to get to it, and that's a lot better for the car than pressing on.
The parts that should be getting lubricated are grinding instead, and the car gives no sign of it: a diesel on a thinned tank fires up and moves off perfectly well. Try the journey home from St Stephen's Tavern? Don't. Phone us and leave the Nissan Qashqai where it stands.
Out there happy, back sluggish. If that was the trip to Cromwell Green, look at the tank. Diesel gets thinned by petrol, and thin fuel leaks past the fine tolerances supposed to build injection pressure — so every extra mile the diesel Audi A4 covered, the less pressure it held onto. Somewhere safe, switch off, phone us.
Pulled off the forecourt, read the till receipt, and left the diesel Ford Focus up close to Winston Churchill a couple of hundred yards later? That is about as well as this goes once the motor has turned. Phone us then leave the vehicle off. The short hop truly assists, but it was still a start and a drive, so weakened fuel has got to the filter and the pump — which is why we rinse your lines rather than only emptying the tank.
Petrol in a diesel does its harm as a share, which is the reason our technicians ask at all: the same few litres sitting in an almost empty tank make a far stronger blend than they would in a full one. And petrol is rated on how well it withstands igniting under pressure — the opposite of what a diesel needs — so a stronger blend knocks more, smokes more, goes flatter. None of which means you need an answer prepared. Almost no one knows how full the tank was in a car collected two days ago, and we work that out on site. Do phone the hire or company firm first, though: some contracts want them to approve the work, and that is far faster settled before than after. Then ring us about the Dacia Duster near PC Keith Palmer GM.
Fixed and starting are not the same thing, and the difference is your system: our technicians flush it, and take your filter off where there's a workable one. Compare that with the certain advice you will get — drain the vehicle, refill with new diesel. Half true. Do precisely that to a diesel Mercedes A-Class by David Lloyd George and it will start, which is precisely why the suggestion sounds reasonable. Then the engine sucks the petrol left behind in the fuel filter, and in the feed lines, straight back through the pump, as draining a tank does nothing whatever about fuel that has already left it. Phone us instead.
A couple of miles on petrol in a diesel: what next?
This is where your M4 matters, under 10 miles out of Westminster. A drop in power, a lumpy idle, some smoke: those are the symptoms when they appear, rather than a neat stop — and a wrongly fuelled diesel will usually get you onto it and some distance along before anything seems wrong at all.
Pull off at the first sensible junction, switch off, and don't restart the car to move it. Long run? Anything near the under 3 miles to the nearest city and you should suppose the lot — filter, pump, injectors, all of it got to by the contamination. Say that on the phone, as it changes what goes in our van.
Where is Westminster?
Westminster is a city located in the heart of London, set on the banks of the River Thames. Westminster sits at a relatively low elevation of 17 metres, with its lakeside setting being dominated by the river rather than lakes. Westminster is home to a large and dense population of approximately 253,458 people, predominantly residing in flats. Westminster is surrounded by notable areas such as Whitehall, Charing Cross, and Lambeth.
Our visit around Westminster, step by step
- The answers shape the work, which is why we ask before giving a price: what was put in, how much of that, and if the engine has run.
- Out comes the contaminated mixture.
- We purge the lines and clean your filter, so what is left in your system isn't what created the problem.
- Clean diesel goes in, and then the system gets primed.
- The motor is started and tested to make sure it runs correctly on fresh diesel.
That has it ready to set off. There is no need to go to a garage at any stage, since the work is all done where the vehicle is, and when it is caught soon, long-term damage is very rare.
AdBlue in a diesel tank around Westminster is a separate problem
The problem is not the same, though the opening step is — don't start it — if what was put in was AdBlue instead of petrol. Petrol dilutes your diesel and removes the lubrication the system relies on. Corrosion and build-up are what a diesel tank gets instead, because AdBlue is urea dissolved in water.
We cover both, and AdBlue removal in Westminster has its own page with the detail — including why it's often the more serious of the two.
How much is a petrol-in-diesel drain in Westminster?
One number wouldn't be fair here, because this isn't one job. These are the things that change it:
- Has it been started or driven? Nothing else counts for as much.
- How much of the wrong fuel went in, set against how much the tank can hold.
- AdBlue or petrol, whichever got in.
- Where is it? And can a van get to it and work there sensibly?
A straight answer instead of a range is what you get for telling us three things: the car, the quantity, and whether it has run. For the vehicle at home that is going nowhere and is not pressing, is fine too.
Things our technicians hear about petrol in diesel around Westminster
At a petrol station in Westminster, can you do a fuel drain there?
Yes — forecourts are where a fair part of this gets done. We visit JET and the other forecourts around town regularly, with the owner's consent — tell us which one you're at when you phone and we'll tell you if we can work there.
A couple of litres of petrol in a diesel — too much?
Litres are not the measure. Proportion is, and much more than either, it counts if anything has been run. What settles how much work is required is whether that mixture has been pulled through the system — since though five litres in a nearly empty tank is a separate case from five in a full one, either way that is the query.
Already driven it with petrol in your diesel? Now what?
Somewhere safe, then stop, then switch off and leave it off. It is salvageable far more frequently than drivers fear, even though driving is what moves the trouble from that tank into the pump and injectors — and the single most valuable thing you can do now is not restart it.
Is a fuel drain going to void my warranty?
A drain and flush carried out correctly is not a modification and doesn't invalidate a manufacturer's warranty. Another good reason to leave it switched off: running a diesel on petrol is the thing likelier to cause a disagreement with one.
Adding two-stroke oil, then driving home
What petrol has diluted isn't replaced by two-stroke oil, which is an old remedy for a distinct problem. So no. The pump still has to cope with it, as your tank still has petrol in it after that.
A main dealer for petrol in a diesel — essential?
No. Our engineers drain and clean the vehicle wherever it is, so there is no need to bring it to a dealership.
You, and the vehicle, still together?
Your engine remains off.
Already driven it? Then stop somewhere sensible, turn off, and let the vehicle remain that way. This is recoverable from far more frequently than people fear, and a still, cold vehicle is the best place to be in.
Throughout Greater London and around Westminster: call-out fuel draining, at home or on the forecourt or at the roadside.