I was filling up my car earlier today, and noticed what looked like steam coming out of the tank. It was an appreciable amount that could clearly be seen, not just a whiff. I've never owned a diesel before, but none of my petrol cars ever did this. Is it normal? I know some fuel goes back to the tank from the pump, but surely it shouldn't get than warm? I'd driven about 150 miles with a short break about halfway prior to filling up.
the entire contents of the tank will be circulated through the fuel pump a good few times an hour, it's the way diesels work.. helps keep the fuel warm and prevent gelling when it's cold and all that.. the pump fills it's self up.. the injectors take what they want.. the excess is taken through the leakoff pipes back to the pump return, and the whole lot goes back to the tank.
the diesel from the petrol station is most likely stored in underground tanks.. so will be a lot colder than the diesel in your cars tank, hence the steam i'd guess,
it could not be steam tho.. if the tank you were drawing the fuel from had ran out, and it changed over.. a diesel re-fueling pump does produce what looks like steam.. seems to scare some people who've never seen it before as it can look like smoke if the lights right, did you look at the pump's numbers as the 'steam' was being produced.. if they were turning slower than usual.. even stopping for a bit, then it'll have been changing over the tanks, and was pumping the vapout in the empty pipes.. dont worry, the pumps dont register the vapour.. hence why the counters stop.
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I didn't look at the numbers, but I did get incredibly pissed off with the pump because it 'clicked' after about 5 litres. Then I couldn't get the damn thing going again even if I just squeezed the trigger lightly and tried all sorts of nozzle orientations. Was about to go and moan at the staff when it started working again and filled the tank to brim in one go.
Your answer would explain both the vapour I saw, and I guess the difficulty with the pump.
Cheers,
Robert
Well he seems an itelligent kind of bloke, I've had similar probs............
My car's a petrol and I see steam almost everytime I fill up. It's worse on hot days though
Its normal. You ought to have seen what came out the wagon tank today.
Are you sure it's steam, and not petrol vapour coming out of the tank? It has a different density to the air around it, and thus refracts light differently - you get the same effect when you look through a column of hot air.
The message from James Dore contains these words:
More likely it's because the tank is at a low pressure 'cos of the emmision requirements. When you release the partial vacuum the sudden drop in pressure causes a sudden drop in temperature which causes any vapour whether petrol or water to condense.
Yes, it's petrol vapour, but you know what we're on about!
Oh yeah, the OP was talking about Diesel :-(
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