Should You Worry? Petrol in a Diesel Car in Racecourse
Not started? Then less worried than you likely feel. Until your ignition primes the pump, the starter turns, or the vehicle is driven, petrol in a diesel tank just rests there and does nothing. Which means the honest reply to the first Racecourse query — "have I ruined it?" — normally no. Petrol in Diesel is who to ring, with the engine kept off, so it stays that way. Further down, you will find what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you again.
The engine and petrol in a diesel: what goes on
Diesel does two tasks on its way through a motor. Lubricating comes before burning; it does both. Extremely fine tolerances are built into the fuel injectors and the high-pressure fuel pump, and only your diesel flowing through keeps their surfaces from grinding together.
Petrol handles the first job poorly and the second not at all. It is runnier than diesel and strips away the protection the system rests on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the knocking comes from.
Combined, those make the shape of the issue plain. The damage is done by circulation, not by contact. Any tank with petrol in it is a fuel issue. After your pump has been labouring on that petrol, a mechanical issue has begun: whatever is shed by a pump that is wearing travels onward to the fuel injectors with the fuel.
Four scenarios our engineers see in Racecourse: how bad is petrol in a diesel?
Filled up, and not started: nothing beats it. That petrol is inside the tank and just the tank, and the job is a drain and a flush where the car stands. This is the one situation that can only really happen on a forecourt, since anywhere else the vehicle has been driven to get there.
Your ignition switched on, or a short start. With the system primed, the lines and filter already contain petrol that has come from the tank. That is generally still a simple task — a drain, a flush, and your filter dealt with.
Driven a couple of miles. Now the pump has spent those miles running on thinned fuel. Miles is only half of that; how hard it was driven counts equally. Either way this work includes the tank, the lines, the filter and clean fuel through the entire circuit. Short trips, like the school run to Murrayfield Primary - A Paradigm Academy, are one thing. A run as far as Colchester, under 25 miles away, is a very different job. So is any mileage on the M11, under 50 miles from Racecourse, where the motor has been labouring hard the whole time.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. That is your engine telling you its fuel no longer is acting like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Packard Avenue. Permanent damage is very rare when a car is stopped quickly, and the drain and flush-through that still go first sort it out.
Racecourse motorists and the petrol in a diesel myths they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing comes out when you top up — that tank simply holds more of the same blend. Percentage is not how a diesel fuel system tolerates petrol, whatever that advice supposes.
Not so: a current diesel copes with a bit of petrol. If anything, the opposite. More precise parts and higher pressure are the way a current diesel runs its fuel, and that makes the lubrication count more, not less.
"It starts, it drives, so no harm done" — the myth that trips up more drivers than any other. Diesel in a petrol motor usually leaves a motor that will not run: the driver stops, and so does the harm. Whilst the pump wears, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old workaround, supposed for another issue. None of what petrol thinned is put back by it — and later, the tank still contains the petrol.
If the motor has been run, part of that petrol sits in the filter and the lines, not the tank — and your next start pulls it right back through your pump. So the myth "drain that tank yourself and you are sorted" doesn't hold. It is also truly hazardous to drain petrol into a can by the roadside.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol motor at all. So the slip runs one way.
When routine and the vehicle stop matching, it occurs. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps arranged differently. Filling up in a rush en route to Derby Road, with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Throw in a back seat full of kids, a phone call or rain, and habit takes over.
Racecourse people: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is only a hint.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before your first fill: many vehicles print the fuel type there.
- Mark your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a safety net, not a reason to stop reading the petrol pump.
- Less petrol makes a weaker blend, so stop the moment you realise — while remembering that the next step is unchanged. It is still not to fire it up.
Put petrol in a diesel in Racecourse already?
The order of things is brief, then. Don't turn your ignition on, and do not start it. Ask the attendants to help you roll it clear of the petrol pump if you're still at the forecourt, whether that is East of England Co-op or anywhere else. What went in, about how much, and whether it has run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue rather than petrol: it is a separate fault, with its own page for Racecourse, because AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel task in Racecourse costs more than another
The four situations above are four different tasks, so no single price for this would be fair. Which of them you are in is mostly what moves your cost. Next it's the share — how much petrol was put in against how much your tank holds — and then where the vehicle is and whether our van can reach it safely.
Three questions come first, before quoting, rather than after — what got in, how much, has it run — and that is the reason. Their answers are what change a range into one firm number.
About Racecourse
Racecourse is a suburban area in Suffolk, situated near the coast and approximately 36 metres above sea level. Racecourse lies within the larger Ipswich urban area, close to neighbourhoods such as Broke Hall and Priory Heath. Racecourse is characterized by its predominantly semi-detached housing stock and is located near Gainsborough. Racecourse is also within commuting distance to Colchester and London, being 16.2 and 67.4 miles away respectively.
Racecourse and Suffolk: where our fuel drain cover reaches
Broke Hall, Priory Heath and Gainsborough are among the locations near Racecourse that the same vans work, answering petrol in diesel jobs across Racecourse's IP postcode area. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
Still at the petrol pump in Racecourse?
Then you are in the best spot there is. Call, and keep it turned off.