Misfuelling a petrol car with diesel

[WinstonEBT]

Hi,

First post and any advice would be greatly appreciated.

Last night the wife put 55 litres of diesel into her Tiguan 1.5 tsi and didn’t realise until she’d driven 2 miles and the dash lit up like a Christmas tree. She stopped immediately and had a man in a van come out to drain the diesel and flush with petrol and get it running.

I tried to take it into a local Indy today but he was closed so shall try again tomorrow. The car starts and runs fine but the EML and EPC are illuminated along with an ACC fault and a stop/start system fault.

I’m praying that it only needs scanned and the faults cleared as it feels like it’s running fine.

Does anyone have any experience of this with this engine and the likely outcome?

TIA

[Matt_E_Mulsion]

There is a good chance that it just needs the fault codes clearing if the car is now running fine.

[Sixpackpert]

Okay, I’ll bite, how did she manage to get the, larger, diesel nozzle in the smaller petrol hole in the filler neck?

[Julian Scott]

WinstonEBT said:

Hi,

First post and any advice would be greatly appreciated.

Last night the wife put 55 litres of diesel into her Tiguan 1.5 tsi and didn’t realise until she’d driven 2 miles and the dash lit up like a Christmas tree. She stopped immediately and had a man in a van come out to drain the diesel and flush with petrol and get it running.

I tried to take it into a local Indy today but he was closed so shall try again tomorrow. The car starts and runs fine but the EML and EPC are illuminated along with an ACC fault and a stop/start system fault.

I’m praying that it only needs scanned and the faults cleared as it feels like it’s running fine.

Does anyone have any experience of this with this engine and the likely outcome?

TIA

Experience - My wife did the same thing, not the same engine though (her's the 1.5 BMW in the 118i), Engine fine (faults cleared themselves after a few 'starts'.

Outcome - Marriage strained. It was somehow my fault anyway and I'm blasted for bringing it up, even though I never do.

[Wacky Racer]

Easy mistake to make, did it myself a few years back, but realised before I drove off the forecourt and started the engine.

AA came out and drained it for £200 and another tankful of the correct fuel was another £50.

I always check ten times before I pull the trigger now, I'm paranoid about it.

[Pica-Pica]

Wacky Racer said:

Easy mistake to make, did it myself a few years back, but realised before I drove off the forecourt and started the engine.

AA came out and drained it for £200 and another tankful of the correct fuel was another £50.

I always check ten times before I pull the trigger now, I'm paranoid about it.

Must have been a long time back if it was only £50 a tankful.

[WinstonEBT]

Matt_E_Mulsion said:

There is a good chance that it just needs the fault codes clearing if the car is now running fine.

Thanks, hopefully all will be fine.

[WinstonEBT]

Sixpackpert said:

Okay, I’ll bite, how did she manage to get the, larger, diesel nozzle in the smaller petrol hole in the filler neck?

That was the first thing I said to her, but tbf, she’s had 25 years experience of squeezing something in that looked too big to fit

[stevieturbo]

Sixpackpert said:

Okay, I’ll bite, how did she manage to get the, larger, diesel nozzle in the smaller petrol hole in the filler neck?

sheer grit and determination.

[stevieturbo]

Wacky Racer said:

Easy mistake to make

As easy as driving into a bus.

[Dashnine]

WinstonEBT said:

Sixpackpert said:

Okay, I’ll bite, how did she manage to get the, larger, diesel nozzle in the smaller petrol hole in the filler neck?

That was the first thing I said to her, but tbf, she’s had 25 years experience of squeezing something in that looked too big to fit

[vikingaero]

Dashnine said:

WinstonEBT said:

Sixpackpert said:

Okay, I’ll bite, how did she manage to get the, larger, diesel nozzle in the smaller petrol hole in the filler neck?

That was the first thing I said to her, but tbf, she’s had 25 years experience of squeezing something in that looked too big to fit

Better than a wizards sleeve.

Main dealers and manufacturers have long peddled doom and gloom about cars being misfuelled. It means a £5,000-£15,000 payday for them and they have an engine with lots of resaleable parts all in the cause of maintaining the warranty. If you've only put a few litres of the wrong fuel in, you need to dilute to buggery and fill up at half a tank for a few cycles with normal fuel.

You misfuel a whole tank. Most sensible people will get the tank drained, filters replaced, code cleared, and properly fuelled up again. That's cost you £250-£350 with the fuel. You'll probably find the car will run fine and have the same longevity and reliability as if you hadn't misfuelled. So what if you misfuel and you've spent £250 on draining, but that hasn't worked? Well, I'd rather gamble £250 over £15k.

[GreenV8S]

Diesel in a petrol engine means it will probably run badly and then stop, and you'll need to remove the diesel and refill it with petrol.

Petrol in a diesel means the expensive fuel injection system will quickly destroy itself. The debris caused by this will fill the whole fuel system and be extremely difficult to clean out, sometimes needing the whole thing to be replaced including tanks and hoses. This is where you see the monster bills.

[WinstonEBT]

Cheers for the reassurance, you’ve put my mind at ease.

The EPC light has gone off and the ACC and sop/start system faults have cleared so it’s only the EML that’s still illuminated at this point. I’ll give it a few more days and see if it clears itself or I’ll take it in to be scanned and reset.

[Dashnine]

WinstonEBT said:

Cheers for the reassurance, you’ve put my mind at ease.

The EPC light has gone off and the ACC and sop/start system faults have cleared so it’s only the EML that’s still illuminated at this point. I’ll give it a few more days and see if it clears itself or I’ll take it in to be scanned and reset.

You can buy a OBD2 scanner from Amazon that plugs in the OBD port and connects to your phone through Wi-Fi for Bluetooth, then use a free app like In Car Doc to read and (if you're happy to) reset the code and EML.

Might be cheaper (at least in the long term) than paying a garage to reset it.

[WinstonEBT]

Dashnine said:

You can buy a OBD2 scanner from Amazon that plugs in the OBD port and connects to your phone through Wi-Fi for Bluetooth, then use a free app like In Car Doc to read and (if you're happy to) reset the code and EML.

Might be cheaper (at least in the long term) than paying a garage to reset it.

I’ve got one already that was bought reset the EML on a corsa but the thing is refusing to connect to any of the cars now. I’ll maybe order another one today and give it another try before taking it in to be done.

ETA, EML has reset itself, so no more warning lights and car is running fine.

Thanks for the help

Edited by WinstonEBT on Thursday 6th October 17:50

[Polly Grigora]

Whatever you don't need to do, do keep it brimmed with the correct fuel for several hundred klicks

[Wacky Racer]

stevieturbo said:

Wacky Racer said:

Easy mistake to make

As easy as driving into a bus.

If you are used to driving your own car, and then one day decide to drive your wife's and you are distracted by something.. (The dolly bird filling up at the next pump with an ultra short skirt and big norks for example) I would suggest yes, it is an easy (and expensive) mistake to make.

[Essarell]

In a moment of complete stupidity I put 20 litres of Adblue into my Diesel tank, moved it a few meters from the pump where one of those “miss-fuel doctors “ drained the tank and fuel system. Took a bit to get it restarted but it ran fine.

[Tony1963]

GreenV8S said:

Diesel in a petrol engine means it will probably run badly and then stop, and you'll need to remove the diesel and refill it with petrol.

Petrol in a diesel means the expensive fuel injection system will quickly destroy itself. The debris caused by this will fill the whole fuel system and be extremely difficult to clean out, sometimes needing the whole thing to be replaced including tanks and hoses. This is where you see the monster bills.

Lol.