Unreliable Gas Guage

[Thom Bonnell]

Hi- i just joined and have a low mileage 2001 Exporer Sport. The gas guge under 1/4 tank is totally strange. it goes up and down and up and down. Was there any fix for this annouced? Do I really have to always have a full tank of gas? I am 70 now,and am so tired of buying gas. Can anyone suggest anything? Thanks.

 

[MyTrac]

Don't let it go too far below a 1/4 tank Mine does that too. I think it stems from a poorly made sensor in the gas tank. I have tried all the gas treatments in the world and it still doesn't help. Generally, I think the gauge going up and down is driven by the fuel pressure within the lines. When you accelerate, the gauge goes up due to higher pressure. when you are at a light, the gauge goes down bc pressure is lower. Still doesn't explain the gauge being accurate over 1/4 tank. But.....im no mechanic or engineer

 

[Schitbrick3633]

I have the same problem in my 02...doesnt make sense

 

[05dakotatrac]

its not un-common on the larger gas tanks in trucks to have a fluctuating gas guage at lower levels. reason being fluid movement at a 1/4 tank you have only 6 gallons and in a large surfaced tank that means maybe 1" of depth wen you accel it flows to the back of the tank nearer our floats but when stopping or stopped the fluid flows forward by momentum causing a lower reading on the gauge. most accurate reading is level ground no motion.

 

[swshawaii]

Don't let it go too far below a 1/4 tank Mine does that too. I think it stems from a poorly made sensor in the gas tank. I have tried all the gas treatments in the world and it still doesn't help. Generally, I think the gauge going up and down is driven by the fuel pressure within the lines. When you accelerate, the gauge goes up due to higher pressure. when you are at a light, the gauge goes down bc pressure is lower. Still doesn't explain the gauge being accurate over 1/4 tank. But.....im no mechanic or engineer

Fuel treatments and fuel pressure affecting the gauge sender? :thumbdwn:

There's a float in the tank that has variable resistance and sends the signal
to the gauge. As mentioned, very inaccurate unless level and stationary.
Try watching a boat gauge, you'll get a much better reading with a dipstick.