Car stalls when the fuel tank goes below half

[theonew]

A short while ago the fuel gauge on my 1995 525i Touring just sunk to empty and the reserve light came on. I resolved to just keep an eye on my mileage and fill accordingly until I could get around to replacing the fuel level sender. So I'm taking a short drive around town, confident that I'm at half a tank of gas when the car stalls, oddly enough right in front of a garage. One of the mechanics comes out while I'm tinkering and gets in the car and tells me that I'm out of gas. And I laugh a bit and tell him that the fuel level sender is broken. He tells me to crank the motor which just barely catches before it dies and he repeats that I'm out of gas. I'm able to roll the car up to the pump and put in 10 bucks of gas and crank the engine confident that my calculations where proper and that the car failed because of other mechanical difficulties, and sure enough it starts. I drive away very embarrassed.

Today I fill the car up to the brim and take off on a 300 mile journey. After about 240 miles of driving it starts to sputter on the highway. I'm just barely able to limp off an exit ramp and get about 500 feet away from a gas station when it completely dies. I walk to the station and get 1 gallon of gas and put it in and after a few cranks it starts right up. I drive to the gas station and fill up the tank and it only took about 10 gallons to fill it.

I'm guessing its the fuel pump.
Anyone have any ideas?

[shogun]

When the car stops the nxt time, open the fuel tank lid and check if there is a hissing sound. If that is the case then there could be somthing wrong with the de-airation of your fuel tank = vacuum builds up in your tank.
You can also try to leave the fuel cap a bit loose on the tank (not tightened so much, that air could enter the tank). If you have a spare cap, drill a small 1-2 mm hole in the fuel tank cap and thry that one.
If that helps you are on the right track.

[Bill R.]

tank has collapsed from a vacum problem by looking under the car at the tank, and also look to see if something has dented the bottom of the tank from being run over, any of those things could push the bottom of the tank up so that the pump is sucking air when its half empty.. if thats all fine, then the pump itself may have come unsecured from its bracket at the bottom of the tank and somehow tipped sideways so the fuel pickup is not flat at the bottom of the tank.. If all these things look ok then there's a problem with the pump itself being weak on the suction side and will have to be replaced.












A short while ago the fuel gauge on my 1995 525i Touring just sunk to empty and the reserve light came on. I resolved to just keep an eye on my mileage and fill accordingly until I could get around to replacing the fuel level sender. So I'm taking a short drive around town, confident that I'm at half a tank of gas when the car stalls, oddly enough right in front of a garage. One of the mechanics comes out while I'm tinkering and gets in the car and tells me that I'm out of gas. And I laugh a bit and tell him that the fuel level sender is broken. He tells me to crank the motor which just barely catches before it dies and he repeats that I'm out of gas. I'm able to roll the car up to the pump and put in 10 bucks of gas and crank the engine confident that my calculations where proper and that the car failed because of other mechanical difficulties, and sure enough it starts. I drive away very embarrassed.

Today I fill the car up to the brim and take off on a 300 mile journey. After about 240 miles of driving it starts to sputter on the highway. I'm just barely able to limp off an exit ramp and get about 500 feet away from a gas station when it completely dies. I walk to the station and get 1 gallon of gas and put it in and after a few cranks it starts right up. I drive to the gas station and fill up the tank and it only took about 10 gallons to fill it.

I'm guessing its the fuel pump.
Anyone have any ideas?

[winfred]

i've seen a couple e34s with their tanks sucked almost flat due to mud dauber nests clogging the vent

[bimmerd00d]

i've seen a couple e34s with their tanks sucked almost flat due to mud dauber nests clogging the vent

I had this exact problem, luckily i caught it before it did any sort of real damage.