Llantilio Pertholey: Put Petrol in a Diesel Car?
Never fire up the motor. While the fuel is still sitting in the tank and your engine has not turned over, a fuel drain is almost always all it takes — and that's determined in the following few minutes, not by how much went in. Petrol in Diesel drains and flushes wrongly fuelled cars where they are, across Llantilio Pertholey and the remainder of Monmouthshire, on the forecourt, at the roadside or on a drive. Ring us and our engineers will tell you what happens from here before you do any more.
The next five minutes: petrol in a diesel
- Feed a petrol engine diesel and it will generally not run at all, so the driver stops there and so does the wear. Feed a diesel petrol and the engine starts, it ticks over, it moves off — fine for several miles. People have that reversed, which is the bit they get wrong about petrol in a diesel in particular. So never start it. And if started, never trust it: your fuel system is grinding as you drive.
- Two things, diesel: it combusts, and on the way through it keeps your high-pressure pump and injectors oiled. Petrol only does the one. That is why the car's ignition is left off also — flick it on and you commonly prime your system, and that's petrol exiting your tank for precisely those parts.
- Don't water down it. Diesel added on top takes out nothing, so all you get is more of what was already there, since percentage isn't how a diesel fuel system handles petrol. Super unleaded? Still petrol. The type makes no difference.
- Stay put if it is sensible to. Hazards on, engine off, keep the car. Wherever you have stopped — the verge on Hanratté Close, anywhere — an odd place for us is better than a started diesel, and nothing is easier for us to sort than a car that never shifted.
- Find out where you are before ringing. A postcode starting NP7 6, and the name of whatever is nearest to you. Otherwise the van circles rather than showing up.
- Three details shape the entire job: the liquid you tipped in, the ballpark volume involved, and if anything has been turning since. Our number is 0333 366 0103.
On the forecourt: draining petrol from a diesel
Pumps are where this job usually starts, and where a good portion of it closes. Our technicians work on petrol station forecourts all the time, with the site's consent, and so if you're still at the nearest petrol station that's normally where this drain happens.
The forecourt is the one spot this can be spotted before the motor has started. Fuel sucked out of that tank and through the fuel filter, right to the high-pressure pump, is what occurs when the motor is switched on 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 covers the filter and the lines along with the tank. That's still not a disaster, and we put it right where your car sits. What decides it is whether the ignition was turned in the seconds after your receipt was checked.
Attendants will usually help out pushing it out from the pump, which lets the next motorist get through. Take the help. Cranking it just to shift four car lengths is not.
We will come to you, drain that tank, clean your fuel lines then put fresh diesel in so you can head home. So if petrol went into the diesel Volkswagen Tiguan around Llantilio Pertholey and you're sat at Morrisons with a boot loaded with shopping, phone — and never crank it again to leave that space. A mile or so at light throttle uses very little of it, so such jobs are often the simple jobs.
Injection pressure is the thing being lost. Petrol thins diesel, and runnier fuel leaks past the close-fitting parts that are meant to build that pressure, so the further a diesel Mercedes C-Class drove, the less well it held. Normal on the way out and sluggish on the way back is how the run to Battery Plantation went, then, and that tank is the place to look. Pull in somewhere safe, turn off and ring us.
Three things help when you call from close to Trebencyn Park: which side the filler is on, whether a van can stand alongside without blocking the road, and whether the motor has run since you filled up. On-street is the usual spot our technicians work, and so the place itself is seldom the trouble — we'd far rather deal with a narrow parking bay than with a motor that has been driven to somewhere more handy. We will drain your Dacia Duster, change the fuel filter where there's a serviceable one, flush the lines and put fresh fuel through the full system, because by this point the worst of it is sitting in your lines rather than in the tank.
Hire car or company car? Ring them before you call us — some contracts want the hire firm to authorise the work, and sorting that out first is a great deal quicker than sorting it after that. Then phone us about the Peugeot 3008 by Tredilion Park, and do not worry that you cannot say how full that tank was. Almost no one can, in a vehicle they collected two days ago, and our technicians work it out on site. The reason our engineers ask is that petrol in a diesel does its harm as a ratio: the same few litres in a nearly empty tank is a far stronger mixture than in a full one. Petrol is rated on how well it resists igniting under pressure, which is the opposite of what a diesel needs — so the stronger the mixture, the more it rattles, smokes and goes flat.
It got a couple of streets and stopped. The throttle went limp, your idle turned ragged, and your diesel BMW 1 Series is now sitting close to Tredilion Fruit Farm. That sluggishness is the fuel failing to build pressure correctly instead of your engine failing — and because there's no warning for it, motors in that position usually get driven once more before somebody calls. Don't. Turn it off and call us.
Do our engineers cover your side of Llantilio Pertholey?
Those same journeys bring us to Mardy, Pantygelli, Pen-y-Pound, Llwyn-du and Cantref along with Llantilio Pertholey, which is a rural hamlet.
If yours isn't on that list it doesn't mean we don't come — there are pages for most towns around Monmouthshire, and the ones mentioned above are simply the closest neighbours. Phone to ask instead of presuming, above all where you are on a boundary or anywhere the satnav misreads.
This map shows the ground this page includes. Roadside, forecourt, drive, car park: all of that is territory we cover, and none of it needs the vehicle to move to us.
Roadside breakdowns in Llantilio Pertholey
Not everybody gets the opportunity to stop somewhere sensible. Hazards flashing at a lay-by somewhere, or pulled onto the verge on Perry Close as you noticed after setting off — our technicians take that call often enough that it is the ordinary kind.
Remain beside your car while it's wise to be inside, yet clear of the car if it isn't. It will usually oblige. A diesel running on petrol limps along very willingly, and that's the catch: fire it up to reach somewhere handier and that mixture goes further into the system with every mile travelled. We will send our van to a tricky location without any fuss, and for the car that's far better than driving on.
Petrol in a diesel, and your car has gone
This is where the M4 comes in, under 25 miles from Llantilio Pertholey. Some way along, and onto it in the first place: a wrongly fuelled diesel will often do both before anything feels wrong. What you get then is seldom a tidy stop. Power ebbs away, your idle goes uneven, and there may be smoke.
The first sensible junction is the one to take. Switch off there, then leave the restarting alone. On a longer run — anything approaching the under 25 miles to the nearest city — assume the petrol has been through the filter, your pump and the injectors, and mention it when you ring. It alters what our technicians bring.
Where is Llantilio Pertholey?
Llantilio Pertholey is a small hamlet situated on the banks of a river in Monmouthshire, with a mix of rural and residential areas at an elevation of around 105 metres. Llantilio Pertholey lies near the communities of Mardy, Pantygelli, and Pen-y-Pound, and is approximately 17.5 miles from the city of Newport. Llantilio Pertholey has a population of around 962 people, predominantly living in detached houses. Llantilio Pertholey is located in a scenic area, with the Welsh countryside surrounding it.
The job around Llantilio Pertholey, step by step
- Three things get asked before any quote — the fuel that went in, the quantity, and whether anything has been run since. Each answer shapes the work.
- We drain your tank of all the polluted fuel.
- Fuel lines are flushed through and the filter cleared, leaving nothing in the system that created any of this.
- Our technicians put clean diesel in and bleed the system.
- The motor is fired up and checked to make sure it runs properly on new diesel.
From there, you're ready to set off. Our technicians do all of this wherever your car has ended up, which means it never needs to go to a garage, and if it has been caught quickly, it is very rare for there to be lasting damage.
AdBlue in your diesel tank instead, around Llantilio Pertholey?
AdBlue rather than petrol? Then the opening rule is unchanged — your engine stays off — whereas this problem beneath it's a different one altogether. The protection a fuel system relies on is stripped away by petrol, which dilutes the diesel. AdBlue is urea in water, and in a diesel tank it brings corrosion and build-up in its place.
AdBlue removal in Llantilio Pertholey has a page of its own with the details on it, including why it is frequently the more serious of the two. Our engineers deal with both.
Llantilio Pertholey costs for a petrol-in-diesel drain
What shifts the price is laid out below, as this job isn't one job and we can't honestly put a single figure on this page.
- Whether the motor has been started or driven. This is the key one.
- Wrong fuel in, against what your tank holds — that ratio.
- Whether it was unleaded or AdBlue.
- Access: the vehicle's position, and whether working on it there's sensible for our van.
Tell us the vehicle, the amount and whether it has run, and you will get a clear answer rather than a range. For the vehicle at home that is going nowhere and is not pressing, works too.
Things we get about petrol in diesel around Llantilio Pertholey
Fuel drains on a Llantilio Pertholey petrol station forecourt
A good part of this work takes place there, so yes. Tell us which one you're at when you call and we'll tell you if our engineers can work there. With the owner's agreement our technicians attend Esso and the other forecourts nearby regularly.
A few litres of petrol in a diesel — too much?
Whether your engine has run matters much more, though the proportion counts too, instead of the litres. What determines how much work is needed is whether that mixture has been drawn through the system — since even though five litres in a nearly empty tank is a distinct matter from five in a full one, either way that's the query.
I put petrol in my diesel and drove the vehicle. What now?
Pull over somewhere safe, turn off, and keep the car off. Not restarting it is the single most useful thing available to you now. Driving does shift the problem out of the tank and into the pump and injectors, yes, and it remains recoverable much more frequently than drivers expect.
Is a fuel drain going to void my warranty?
A manufacturer's warranty withstands a drain and flush done to a good standard, which is no modification at all. Another good reason to leave it switched off: running a diesel on petrol is the thing more likely to cause a disagreement with one.
Could I put some two-stroke in and just drive?
No. Two-stroke oil is an old workaround for a different problem and it doesn't restore what petrol has thinned. Petrol remains in that tank later on, whatever else goes in, and the pump gets no break from it.
Main dealers and petrol in a diesel
You don't need one. The vehicle is drained and cleaned wherever it is, with no need to bring it to a dealership.
Is the car still with you?
Keep the engine turned off.
Already driven it? Then pull in somewhere sensible, turn off, then let the car remain that way. Cold and stationary, a vehicle is in the best position available — and motorists fear this far more than the recovery rate warrants.
At the kerbside, on the forecourt or at home — mobile fuel draining around Llantilio Pertholey and across Monmouthshire.