Best way of removing petrol from hdi :(

Slyman · Unread post by **Slyman** » 03 Jun 2007, 17:29

Hi, wife was driving home from shopping and decided to fill up at local garage, less than a mile away. She arrives home and says car is not running well and the ant-pollution light is on !
So out I go to inspect and after a lot of head scratching I look at the reciept and it says 30lts of unleaded.
So what is the best way to remove the stuff ? I have an old electric petrol pump and some hose or should I just disconnect the fuel lines and use the in tank pump?
I know petrol is bad news for hdi pumps but it was only a mile and a 60/40 mix.
The car is a C5 2.0hdi estate.
Thanks in advance
Simon

weety · Unread post by **weety** » 03 Jun 2007, 17:38

i have no expirience with HDI's but i doubt you can siphon with the anti syphon tanks so i would say your best bit is to disconnect the fuel line and try to suck the fuel out using your pump.......... trouble is i dont know if you would need the lift pump working to do that though

its just a guess but if you use the lift pump wont the fuel be coming out at tremendous pressure?

nick · Unread post by **nick** » 03 Jun 2007, 17:41

I don't think the in-tank lift pump produces too much pressure, something like 2 bar if I remember rightly so could be used. Trouble is, I doubt it will empty the tank right to the bottom, they're normally designed to leave the residue in the bottom of the tank alone.

weety · Unread post by **weety** » 03 Jun 2007, 17:42

would that matter if it was diluted down with a full tank of diesel?

nick · Unread post by **nick** » 03 Jun 2007, 17:45

Perhaps not, I suppose a litre or two of derv/petrol mix combined into a full tank of derv wouldn't do too much harm (famous last words!).

jmd · Unread post by **jmd** » 03 Jun 2007, 18:00

MY EXPERIENCE - with older Xantia engine. For what its worth I put 24 Ltrs of Petrol into my near empty tank, when I discovered my mistake, then filled the remainder of the tank with Diesel, after a reluctant start I put in a pint of ordinary engine oil in the tank, (to lubricate the pump seals) and continued my journey 130 miles home - a lot of smoke was to be seen from my exhaust. On arriving home filled the tank with diesel (took about 15 Ltrs) smoke disappeared and all went well. The car had 80,000 miles on the clock then, and now has 254,000 no pump problems ever. M.P.G improved by about 5 M.P.G after this. I believe it was due to all carbon having been burnt out of the cylinders. Your HDI engine might be a different thing, and not so petrol friendly. In your case I would get out as much as possible of the cocktail in your tank out , (I wouldn't worry if I didnt get it all, and refill your tank with Diesel, -this will dilute whatever is left in the tank, add a pint of lubricating oil to your tank. Gradually reuse the cocktail that you get out of the engine, perhaps add a gallon of it to each tankful of Diesel. Good Luck.

nick · Unread post by **nick** » 03 Jun 2007, 18:13

jmd wrote:Your HDI engine might be a different thing, and not so petrol friendly.

That's the problem, HDi's are very unfriendly to anything except pure derv! I wouldn't have worried about it too much in an XUD, but there are numerous horror stories of common rail diesels needing complete new high pressure pumps and injectors after this type of episode.

jeremy · Unread post by **jeremy** » 03 Jun 2007, 18:15

I think the HDi is rather more sensitive than the old mechanical pumps - as it operates at about 10,000psi rather than 1800 - which means that the high pressure pump is probably made to finer tolerances . . . .which means its rather more delicate and sensitive to abuse.

I'd get it all out - the low pressure pump will probably do the job if the car's on the flat. I don't know how its wired - high pressure (36 psi or so) petrol injection pumps only work when the engine is starting (starter operating) or running - for safety reasons - you don't want petrol pumping at 36 psi over hot parts in a crash.

There may be some form of similar cut out on the tank pump - in which case an independent 12 volt supply may be needed - but disconnect the thing first as I don't know what will be at the other end of the wire and an ECU may not appreciate being fed backwards as it were.

Its up to you but you may feel that massive dilution is the best way to deal with any dregs in the tank. You may also feel its worth emptying the pipe running forward to avoid another 10 ft of mixed fuel.

The problem here is that all components are so expensive for the HDi (110 may be worse than 90 for injectors - due to phasing of injection on 110) that you don't really want to risk any more damage.

davethewheel · Unread post by **davethewheel** » 03 Jun 2007, 18:30

a friend of mine put unleaded into a vw passat tdi and the AA said up to 5 ltrs of unleaded and you can just fill the rest with Diesel any more and you have got to get tit drained.

weety · Unread post by **weety** » 03 Jun 2007, 18:44

the diesel injector cleaner you get on the market is really just petrol plus a few other ingredients.....the old XUD9 would just soak up that sort of abuse (some people running on veggy run 90% veggy 10% unleaded)

but an HDI.... bit of a dark art........

how about taking the entire tank of? then you wont have to worry about electrics/ECu's going pear shaped

nick · Unread post by **nick** » 03 Jun 2007, 18:51

The connectors to the in tank pump are just a push fit, so it should be possible to unplug the supply cable and connect an alternative source of 12V directly to the pump to power it without having the ignition on. No risk of ECU damage doing it that way.
Be very careful of sparks though, not normally a problem with a diesel tank, but with a few litres of petrol in there......

Slyman · Unread post by **Slyman** » 03 Jun 2007, 19:28

Just had a quick look and the in tank pump looks easy enough to remove, big screw ring around it, so what do you think of taking it out then poking a long pipe in from my pump ?

weety · Unread post by **weety** » 03 Jun 2007, 19:41

Slyman wrote:Just had a quick look and the in tank pump looks easy enough to remove, big screw ring around it, so what do you think of taking it out then poking a long pipe in from my pump ?

definately removeable if its the same as the XUD9 ones (though you will probably need to 'gently' tap it round with a hammer and screwdriver)

cant see why your plan wont work.......

Unread post by **Peter.N.** » 03 Jun 2007, 19:50

The older IDI engines suffer very little with quite a high proportion of petrol, in fact, in the days of waxing fuel and cold winters, I would often pour a gallon of petrol in to keep going. For a limited period of time you could run on more than 50% petrol, but that. as I say. is with IDI engines. Hdi engines are a different kettle of fish, the tremendously high pressures involved put a lot of strain on the pump and injectors and lack of lubrication could lead to expensive failures. I would think they would tolerate some petrol , but I wouldn't like to be the person discovering how much.

Slyman · Unread post by **Slyman** » 03 Jun 2007, 20:08

Well im just about to discover so ill let you know