HELP NEEDED! I can never fill up the tank at once. Should I let it be? ill effects?

autoque · #1 10-12-2010, 05:05 AM

The 08' 3.0 X5 has been having this problem since new, right off the dealer lot.

I fill up the gas tank till the pump clicks. I start the car and see the gauge a bar less than full (a small bar). So I get out and pump again, click after click, about one and a half gallon more goes in. I go back and start the car again and see the bar at full.

That's the ritual I go though at every gas station. The car went in for service but the tech told me to fill up the car slower so gaseous air would have time to ventilate. In short, don't use the pump at full power. The tech didn't have permanent fix for it and I didn't push it.

The car's still under warranty but I think it's not a big deal so I'm willing to just let this one go. But will it have a negative impact on performance? The pressure in the gas tank might be off due to faulty ventilation. Or is it? I'm not sure in the long run if this will haunt me back as a performance lag or lower reliability. Or if it's just a small annoyance which has no other ill effects. Any help is greatly appreciated.

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genemish · #2 10-12-2010, 07:55 AM

i have same result (2010 X5 4.8) ONLY when the car is running during the fill up...

MRV99 · #3 10-12-2010, 11:15 AM

1 take the car in. Could be a faulty fuel level sensor which I believe means new fuel pump. 2 Never fill a BMW with it running. You will get error message

ard · #4 10-12-2010, 01:23 PM

Agreed, never fill ANY car while running... the lack of a closed fuel tank vent system CAN trip a CEL light that will annoy you until it clears. Folks don't realize this, freak out, and was everyone's time with a dealer visit.

Second- OP- how much fuel do you get into your tank when you run it to empty? Could be a calibration issue.

(Oh, why do you stop at the first click, get in the car and start it, then get back out???? If this is the ritual, just give it half a gallon after it clicks the first time and be done with it!)

stockguru · #5 10-12-2010, 01:50 PM

I have this problem only when the pump is set to automatic (meaning someone is not holding the pump)

JCL · #6 10-12-2010, 02:37 PM

Quote:

Originally Posted by autoque

The car went in for service but the tech told me to fill up the car slower so gaseous air would have time to ventilate. In short, don't use the pump at full power. The tech didn't have permanent fix for it and I didn't push it.

The car's still under warranty but I think it's not a big deal so I'm willing to just let this one go. But will it have a negative impact on performance? The pressure in the gas tank might be off due to faulty ventilation. Or is it? I'm not sure in the long run if this will haunt me back as a performance lag or lower reliability. Or if it's just a small annoyance which has no other ill effects. Any help is greatly appreciated.

The tech was correct. Every pump has a different flow rate. Use a slower pump, or top it off manually once it the auto pump latch clicks off.

It is not a big deal. The tank doesn't vent through the onboard emissions system when you are filling it, the fumes come back out the filler neck (and are possibly captured by the pump vent capture system, depending where you are and what local regulations are).

JDav · #7 10-12-2010, 05:53 PM

I have a similar issue:
When I fill up (and the pump "shuts off") and then get in and turn on the X, it only appears that I am halfway full. After driving for a bit, the fuel level gauge slowly goes up. Get home and turn the car off. Next morning, it still doesn't look full, but as I drive more, it goes slowly up again. Finally reaches about 7/8ths full before acting like normal and decreasing as I drive.

autoque · #8 10-12-2010, 08:25 PM

Quote:

Originally Posted by ard

Second- OP- how much fuel do you get into your tank when you run it to empty? Could be a calibration issue.

(Oh, why do you stop at the first click, get in the car and start it, then get back out???? If this is the ritual, just give it half a gallon after it clicks the first time and be done with it!)

I don't remember 'cause it was some time ago I ran it empty and filled it up. I knew at the time but now the memory is sort of fuzzy.

I check after the first click because I don't want to run the risk of fuel flowing out of the fuel tank. Because when I try to pump it down after the first click, I have to sort of force it down click after click.

Quote:

Originally Posted by JDav

I have a similar issue:
When I fill up (and the pump "shuts off") and then get in and turn on the X, it only appears that I am halfway full. After driving for a bit, the fuel level gauge slowly goes up. Get home and turn the car off. Next morning, it still doesn't look full, but as I drive more, it goes slowly up again. Finally reaches about 7/8ths full before acting like normal and decreasing as I drive.

Actually this happens, somtimes, if I just drive away without filling up the last bar. I think it has something to do with the fuel getting hot and expanding so the gauge registers slowly as a bigger volume of fuel.

Yeah, like I said, it's not a big deal. Just wanted to make sure it's not going to haunt me back when the warranty's over.

Thanks all! Appreciate it.

autoque · #9 10-12-2010, 08:26 PM

Quote:

Originally Posted by stockguru

I have this problem only when the pump is set to automatic (meaning someone is not holding the pump)

I DO use automatic!

autoque · #10 10-12-2010, 09:40 PM

Quote:

Originally Posted by MRV99

1 take the car in. Could be a faulty fuel level sensor which I believe means new fuel pump.

If a fuel level sensor is faulty then why would I need a new fuel pump? Shouldn't the fuel level sensor be replaced if it's faulty? I'm just using common sense.

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