Board logo

Just put 20litres of petrol in Audi A4 deisel
John G - 18/11/17 at 04:05 PM

Just managed to put 20 litres of petrol in my Audi A4 tdi 2001. Did not start the car and the rac will bring it to my house. Any ideas on draining the tank?
Regards, Jon


rusty nuts - 18/11/17 at 04:20 PM

Some of the VAG diesels it's possible to disconnect the fuel supply pipe to the footer housing and use a workshop type scanner to operate the in tank pump to empty the tank . I emptied a neighbours tank on his Audi by disconnecting the tank unit multi plug and using a power probe to operate the pump. It may be possible to use a vacuum type oil drainer to suck the fuel out if you have one? Alternatively do you have a local specialist to drain it for you?


jossey - 18/11/17 at 04:48 PM

Call someone out to drain it.


sandhu - 18/11/17 at 04:51 PM

Fill max up with diesel . Should be ok
Done in a landcruiser


drt - 18/11/17 at 05:06 PM

How big is the tank, you can get away with up to 12% petrol in diesel (ask people from cold countries).
But since this is a PD engine (if I'm not mistaken) you won't risk destroying the high pressure pump...
So I am inclined to agree with just throwing diesel on top.

If you are in an DIY mood to drain it...
Jack up, disconnect fuel filter put 12v directly on fuel tank pump.
Or go to cheap chinasium shop, buy camping style airpump, and use suction side.
Or go to DIY store they have cheap things for that, EG
[ebay]https://www.ebay.co.uk/itm/Petrol-Syphon-Siphon-Pump-Kit-with-2-x-1-2m-Transfer-Tubes-Drain-Fish-Tank/201409292889?epid=944034019&hash=item2 ee4edea59:g:pRMAAOSwU9xUPj-m[/ebay]


Mr Whippy - 18/11/17 at 05:06 PM

quote:
Originally posted by sandhu
Fill max up with diesel . Should be ok
Done in a landcruiser


A lot of fuel wasted though if the engine runs badly

Might adjust the mixture to suit, might not. I'm sure a landcruiser would be a lot more forgiving


mark chandler - 18/11/17 at 06:15 PM

Put £25 of petrol into my D5 Volvo, just crammed to the top with diesel and drove it, seemed to go better.

Once it was 3/4 full topped off, did this a couple of times to dilute it further then just ran it down.

Car was fine afterwards, it had HP pump and electronic injection.


sam919 - 18/11/17 at 07:22 PM

Ditto - done it to an A4 diesel ,kept on diluting it no problems.


macc man - 18/11/17 at 08:37 PM

I did this on a a kangoo van. I used the priming bulb to empty the tank. Took a while but did the trick.


SteveWalker - 18/11/17 at 09:27 PM

When my dad did the same, I went round and we disconnected a fuel hose, directed it into a container, disconnected the fuel pump wires and connected a 12V supply to the pump. We pumped it all out. Refilled with clean diesel and then over a period of time, he used the contaminated stuff up a bit at a time - a few litres in each tankfull.


nick205 - 19/11/17 at 02:07 PM

Filled my 2007 Passat TDI from empty to full with petrol. Ran for 200 metres and stopped. Paid a local garage to drain, fill with diesel and change the fuel filter. No harm done to the engine, did another 30k miles no trouble.

I'd say do the same with yours.

[Edited on 21/11/17 by nick205]

[Edited on 21/11/17 by nick205]


Angel Acevedo - 20/11/17 at 08:42 PM

quote:
Originally posted by drt...
Or go to cheap chinasium shop, buy camping style airpump, and use suction side.
...

I saw a chapter of dumb ways to die (Or strange ways to die) where two guys used a vacuum to suck fuel from a petrol tank and died from the ensuing explosion.
I don´t think diesel gives enough fumes, but with petrol there may be plenty.


ste - 20/11/17 at 11:24 PM

I would remove the engine and fit a petrol engine in until the tank is empty, then refit the diesel engine and fill up with diesel


coyoteboy - 20/11/17 at 11:33 PM

quote:
Originally posted by macc man
I did this on a a kangoo van. I used the priming bulb to empty the tank. Took a while but did the trick.


Bet you look like Popeye now!


drt - 21/11/17 at 12:46 AM

Correction !
PD engines can't cope with the petrol.
so only the older 'line pumps can' and maybe the rotary pumps too.
but PD and CR not apparently

see;
http://www.autobild.de/artikel/diesel-im-winter-40027.html

''Früher genehmigten Dieselfahrer ihrem nagelnden Gefährt im Winter an der Dieselsäule oft noch einen Schluck Benzin. Das steht zwar auch heute noch in einigen Betriebsanleitungen, aber modernen Common-Rail-Diesel oder Pumpe-Düse-Motoren droht durchs Benzin sogar der Pumpentod.''


In short.
Petrol use to be added to fight crystallization (temps below -15°C). It's still in the manuals today, but modern CR and PD suffer pump death.
(this is because petrol doesn't lubricate and even prevents the diesel from doing so, at 800bar+ pressure it doesn't need a lot to die)

(FYI This is the main reason why we had direct injection diesels way before the petrol counterpart)


John G - 21/11/17 at 08:14 AM

Quick update, after messing around, lifting up the back seat removing panels, syphoning out 3 litres, attatching a fuel pump to the syphon, then to the fuel feed I gave up. Phoned up a company and watched the bloke pump it all out with a VERY powerful pump. £130 lighter in pocket but back on the road. Having seen it done I would never have done it without the pump.


Mr Whippy - 21/11/17 at 12:25 PM

oh the good old days when you had a fuel tank drain plug...

My landrover has a 1/2 in NPT plug which tbh is a total over kill