Petrol in a Diesel Car in Motspur Park: How Worried Should You Be?
If it has not been started, you can worry less than you probably are. Until the ignition primes the pump, your starter turns, or the car is driven, petrol in a diesel tank simply rests there and does nothing. Which means the honest reply to the first Motspur Park query — "have I ruined it?" — normally no. Keep it that way: leave your motor off then phone Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never repeat it.
Inside the engine: what petrol in a diesel does
Two jobs fall to diesel on its route round a motor. It lubricates first, and only then does it burn. Built to very fine clearances, the injectors and the pump rely on the diesel moving through them to stop their surfaces wearing against one another.
Badly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump on the mixture to wear itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Put those together and the shape of the issue is plain. It is movement that causes the harm, not contact. All a tank with petrol in it amounts to is a fuel issue. Whatever a worn pump sheds travels on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical issue begins.
Motspur Park, petrol in a diesel: four cases, from mild to major
Fuelled, and not started: no case is better. That petrol is inside that tank and just the tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only really happen on a forecourt, since anywhere else the vehicle has been driven to get there.
The ignition switched on, or a short start. Your system has been bled, so petrol has left the tank and got to the fuel filter and the lines. That's normally still a straightforward job — a drain, a flush, and the filter seen to.
Those few miles driven were the pump working on fuel diluted by petrol the whole way. Tank, lines, filter, then fresh fuel put through the entire circuit: that is the work, and the way the vehicle was driven matters as much as the distance. The school run to Green Lane Primary and Nursery School is one thing. Driving as far as Westminster, under 10 miles away, makes a very different task — as does any miles on the M25, under 10 miles from Motspur Park, with your engine labouring hard all the way.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven until it complained. That is the engine telling you its fuel no longer is acting like diesel. Pull up wherever you are — the verge on Hopton Gardens, a lay-by, a side street — and leave the car there. What goes first is still the drain and flush, and that sorts it out, with long-term damage very unusual when a car is stopped quickly.
Petrol in a diesel myths Motspur Park motorists hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed when you top up — your tank just carries more of the same blend. That guidance supposes a diesel fuel system tolerates petrol by percentage. It does not.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that is how a newer diesel handles its fuel, so the lubrication counts for more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that catches motorists. Feed diesel to a petrol engine and it usually won't run, and so the motorist stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive the car home." It is an old fix for a distinct problem. It doesn't put back what petrol has weakened, and that petrol is still in that tank later on.
The next start sends petrol back round the pump from the fuel lines and your filter, where some of that ends up once your engine has been run. That is why a DIY tank drain doesn't leave you sorted — a myth. It is also truly dangerous to drain petrol into a can by the kerbside.
Why petrol in a diesel happens at all
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the slimmer 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 car at all. So the error runs one way.
Routine and the car falling out of step is when it occurs. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. The pumps in a different order on a well-known forecourt. Filling up in a rush en route to the nearest station, with a train to catch. A new-to-you diesel Renault Clio, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. Add a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up around Motspur Park: preventing petrol in a diesel
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on each forecourt. The label is what matters.
- Plenty of motors state the fuel type inside your filler flap or on the cap, so check it on your first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, in a household with one of each.
- Before the nozzle comes off the pump the first time you fuel a hired or new motor, say "diesel" aloud. Silly, yes, but it works.
- While you're thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and aftermarket devices are available for the rest. Treat it as a backstop, and keep checking the petrol pump.
- Less petrol makes a weaker mix, so stop the moment you realise — while remembering that the next step is unchanged. It is still not to crank it.
Put petrol in a diesel around Motspur Park already?
Then the order of things is short. Leave it unstarted, with the ignition switched off as well. If you're still at the forecourt — Esso or anywhere else — ask the staff to help you roll it away from the pump. Then ring 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
Say so if it was AdBlue instead of petrol: it's a different problem, with its own page for Motspur Park, since AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel job around Motspur Park costs more than another
An honest single price doesn't exist here: four situations, four separate jobs. What moves your cost is chiefly which of them you are in. The share matters next, meaning how much of that tank is petrol, followed by the location of the vehicle and whether getting to it is safe for a van.
Before any quote, not after, we ask three queries: your fuel that got in, its volume, and whether it has run. That is why. A range turns into a straight figure when those replies are in.
About Motspur Park
Motspur Park is a suburban area in southwest London, situated near the River Thames and close to the neighbouring districts of West Barnes, Old Malden, and New Malden. Motspur Park has a relatively low elevation of 19 metres above sea level and is characterized by its terraced housing stock. Motspur Park is located approximately 9.4 miles from central London, with Westminster being the nearest city at 9.1 miles away. Motspur Park is home to a population of around 6537 residents.
Fuel drain cover around Motspur Park and across Greater London
Motspur Park waits in the KT postcode area, and the teams that answer petrol in diesel call-outs there work the locations around it as well — West Barnes, Old Malden and New Malden among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places we work, and your car doesn't need to come to us.
Motspur Park: still at the pump?
No position is better: that's where you now are. Keep it off. Call.