Fuel guage not working correctly

[paphillyman]

Hi , I just got a 1996 BMW Z3 1.9L with 83000 miles on it . I went to fill it with gas and it only took like 3 gallons of gas and the gas guage read 1/4 tank , as I drive it after like 60 -70 miles the light goes on saying I'm close to empty . . My question is , do I still have like 9 or 10 gallons left or do I need to refuel , I do realize I probably need a new fuel pump or sending unit , but just wondering if I can still drive it and rely on how many miles I went and wait til I go 250 miles or so before I refuel , just don't want to run out of gas and get stuck somewhere.

 

[Low Rider]

You should be fine refuelling ever 250 miles. I have a 2.2 I'm getting 290 miles per tank

 

[colb]

Sounds like the tank sender is at fault but check the guage out to see if it works across the full range by doing an instrument self test using the odometer button. Details here on how to do it.
http://www.zroadster.net/forum/viewtopic.php?f=18&t=20201&p=191422&hilit=instrument+test#p191422

 

[paphillyman]

ok , well that sounds good , was afraid I would have to take it in and have a mechanic look at it and fix it , at least I can drive it and just watch how many miles I go after I fill it up and I will check out doing an instrument self test using the odometer button . One thing I did do is pulled fuse # 31 and #46 but that didnt work so I will try the instrument test thing , thanks for the tips

 

[ZZZZZ]

The tiny white ceramic circuit board in your fuel sender unit is broken or super dirty. You can find the specific snall part on fleabay for a few bucks instead of buying a 400$ fuel sender unit. Google it, a gazillion topics worldwide on all BMW (z3) forums about this issue. Eventually ANY Z3 will suffer from it, design flaw in tank breathing systen.
Replace your active charcoal filter as well otherwise this problem returns in no time.