I have a 2007 MC Hardtop, not an 'S". 120,000 miles, all stock.

My fuel pump died a few weeks ago; just quit as I was driving to work. So, since I was an hour from home(I have a long commute), I had it towed to a local independent shop. No Mini or BMW dealer in the local area. Mechanic seems very competent and quickly diagnosed the problem and ordered a fuel pump. New pump installed.
So here's the strange part. I am currently on my 4th pump in a month. Nothing wrong with the pump itself, but can't get the gauge to work properly. First 2 pumps were from mechanics parts supplier and were Delphi brand. Both came in damaged and even though the pump worked the gauge would not.
Third pump was another Delphi from a different supplier. Gauge would seem to read ok, but then after counting down to about 120 miles left and 3 or 4 lights lit, it would start to count back up again! So we got a 4th pump from the Mini dealer. This one seemed to be working great except that when the tank was first filled up, it would not light up all the lights. Then after sitting overnight, all the gauge lights were lit. Gauge seems to be counting down pretty accurately (although I think the float needs a little adjustment) but, after I fill up the tank it keeps counting down until it shows empty! Then the next day after sitting all night, the gauge shows the correct amount.
I have let the tank run down until almost empty and then filled up and have refilled the tank with only 1/4 gone and both times it does the same. I am really confused.
Planning on taking it out myself this weekend to see if the mechanic goofed something up. Hoping someone could maybe shed some light on this.
thanks!

 

Your fuel gauge is shorted out, happen to my Mini over 2 years ago. When I filled it up it would show one moment 90% full with one bar not lit, then it would show 2 bars lit on a full tank.

 

When searching, I ran across Systemlord's thread about it here. May be a good idea to check things out and see if it may be your cause before replacing more parts.

 

How funny I forgot about my own thread with two YouTube videos and a very annoying GL in the passenger seat!

 

thanks for the replies. I read your other post Systemlord and my gauge glows bright and dim as well.
Where should I look for the short? Under the rear seat by the pump and/or filter? I did have the filter replaced as well.

 

With my R56 I had the same problem, tried replacing everything short of the fuel tank with no dice. I just started keeping track of mileage and would fill up at around 280 miles.