Syphoning fuel

notanewuser

Lum wrote: »

Can't beleive siphoning a tank before a sale. If it's off to the scrapyard or a write off heading to the insurance company than fine.

For the latter I just cut the fuel line in the engine bay, stuffed the offcut into a hose to a can and then jumpered the fuel pump relay.

Scrapped a car last month with about 25l of unleaded in it. Wasn't worth trying to get the fuel out. Neither of my other cars run on unleaded.

vaio

TradePro wrote: »

Are you sure? Petrol fumes don't need much provocation to ignite...

Don't know about the motors but don't forget that petrol fumes will only burn in a very narrow band of concentrations in air.

Anything less than 1.2% or more than 8% and it won't burn.

In a tank that has any liquid petrol in it I'd guess the fume concentration is going to be close to 100% so won't burn

Weird_Nev

I had a BMW which had a loose +12V wire in the fuel sender which must have made contact with the pump body or one of the other spade terminals countless times before I diagnosed the problem and sorted it. I'm still here to tell the tale.
Perhaps taking a flash photo of the job in progress wasn't the best idea though....

red_eye

westwood68 wrote: »

Not on an old diesel like mine. The only fuel pump is next to the engine and driven mechanically when the engine is running. That's why there's a need for a manual priming bulb to rescue idiots me who either run out of fuel or have the need to flush the system.

I was talking about petrol, you can use an angle grinder to shower diesel in sparks and it will never set alight. that bulb is also for when you change the fuel filter............you have changed the filter haven't you?

red_eye

TradePro wrote: »

Are you sure? Petrol fumes don't need much provocation to ignite...

very sure it was a mondeo or something old, I used to work in an undercover breakers:cool:. when immersed in fuel a spark wont do anything and there is something about there being little to no oxygen in the tank

mttylad

As a warning to anyone considering removing the locking ring and taking the sender unit out on the top of a tank to syphon petrol out.

If you tank is non metal (I.e. the plastic type) and the tank is full, it can warp the tank and the locking ring may not be able to be screwed back on, requiring you to replace the tank.

I was told this is a common problem when it happened to my Scenic a couple of years ago. I was lucky I could get a replacement tank fitted very cheaply. You have a very limited amount of time to remove the ring to replace the sender unit.

Empty the tank beforhand and its not a problem - but thats contrary to this threads reason to do it.

Avoriaz

notanewuser wrote: »

Scrapped a car last month with about 25l of unleaded in it. Wasn't worth trying to get the fuel out. Neither of my other cars run on unleaded.

If your other cars run on diesel and you had enough jerry cans you could have added small amounts of that petrol to the diesel over time without any problems and saved yourself about £33.

A few percent petrol in diesel shouldn't cause a problem.

Personally I wouldn't have bothered; too much effort and risk and I only have one 5litre can; but this is supposed to be a money saving site.

Jamie_Carter

vaio wrote: »

Don't know about the motors but don't forget that petrol fumes will only burn in a very narrow band of concentrations in air.

Anything less than 1.2% or more than 8% and it won't burn.

In a tank that has any liquid petrol in it I'd guess the fume concentration is going to be close to 100% so won't burn

1.2 to 8% is actually quite a wide range.

If the concentration was 100%, then it would be liquid. The vapours would be a mixture of petrol and air.

Jamie_Carter

Weird_Nev wrote: »

I had a BMW which had a loose +12V wire in the fuel sender which must have made contact with the pump body or one of the other spade terminals countless times before I diagnosed the problem and sorted it. I'm still here to tell the tale.
Perhaps taking a flash photo of the job in progress wasn't the best idea though....

The non intrinsically safe components would all be external to the fuel system. So unless there is a leak there should be no risk of ignition.

Jamie_Carter

Avoriaz wrote: »

If your other cars run on diesel and you had enough jerry cans you could have added small amounts of that petrol to the diesel over time without any problems and saved yourself about £33.

A few percent petrol in diesel shouldn't cause a problem.

Personally I wouldn't have bothered; too much effort and risk and I only have one 5litre can; but this is supposed to be a money saving site.

Apart from it damaging your fuel pump.

Remember diesel lubricates, but petrol can be used to remove oils. Diesel pumps are designed to be lubricated continuously.