hi,

my father has put petrol in his volvo v70 2.4d 05 reg which is a diesel, obviously not good i need to find out how to drain the tank as i cant seem to syphen it from the diesel cap, guessing its an anti theft system in place but ther must be another way to drain it without calling in a specialist...

as far as i got i have lifted the rear seat to uncover inder the carpet a metal plate held in by 4 10mm bolts and that has underneath a black plastic cap with a white platic cap in the middle with an arrow moulded onto it i was guessing that arrow needed to be aligned to another arrow or mark on the black outer plastic but cannot turn either of them...

can anybody enlighten me?

 

You need to fashion a spanner to remove the retaining ring - black outer ring with the teeth to accept the spanner. Tapping alternate sides might work, but not the best especially when putting it back together.
Un-do anticlockwise. Remove ring and center(white) portion.
Reassemble using arrows pointing as they were, rearward.

Bummer Dude,
ED7

 

Or, get a pump with a long hose and pump it out. Let it air out, too. Don't use the infamous "lit match" method, however! 1 or 2 percent "petrol" in a refilled tank of diesel won't kill the motor. Just make sure you pump as much out as possible. Tapping the tank from underneath as you are draining will help you determine (along with the fuel gauge and low fuel light) if you're getting to near empty.

Your problem isn't just the tank, however. Your fuel pump, your fuel lines and your fuel rail probably have gas in them. Can you get to the fuel pump on a Volvo diesel? Don't know since they haven't been sold here in years. If you can, drain it and run diesel through it. (A 12 V battery should power it up.)

The fuel lines from pump to rail might need some air assistance. When both ends are undone, low pressure air should blow them out. Gravity should do most of the work, but they won't be any drainage unless you open the end at the fuel rail/distributor, too. BTW, if there is a fuel filter or filters, replace them if possible as they are mini resorvoirs.

I've never seen a modern Volvo fuel real and injectors, so I can't help you there. Removable without dissembling the intake and/or engine? Can they be "opened" to drain out the gas? Don't know. Sorry.

In the cold north where I live, diesel operators occasionally put a little gas (a small amount) into the diesel tank to keep it more fluid in cold weather. So a 1 or 2 percent mix won't blow up your engine. But you don't want pure gas entering the combustion chamber and exploding/burning out of sync with the engine's operation. That high compression is more than the engine can stand.

 

Draining the tank and changing the filter is all that is necessary.
You've got to bleed the air from the system, and with that comes the rest of the gas.
Ed7