Hey all I just bought a 1997 F 250 XLT 2WD and I believe I am having some issues with either my gas gauge or maybe even my gas tank. I just filled it up the other day around 12 gallons and it said it was completely full on the gauge. Now I started a new trip once I filled up. Now I'm at 86 miles into that trip and the gauge has a quarter of a tank left. Now I do have the dual tank reservoir system and the front one is the one I filled. From what I've read both should roughly hold 19 gallons. Any suggestions on what to do or check. Please keep in mind I'm not good with cars and this would require a detailed explanation. Please and thank you for any future help that you may give me.

 

Hello, A couple things, what body type is the truck? Crew cab? regular cab? and what bed length is it? Also what engine, 351 (5.8) or 460 (7.5)? Also before you put in the 12 gallons where was the gauge at? The front tank might only be about a 16.5 if it is stock on a regular cab and means you may be getting bad gas mileage, but that is extremely low even for just bad gas milage, on the extreme side it could be a fuel pump, does the rear tank do about that bad on milage? Mine did something similar and needed new fuel pumps and put milage right back up to normal! (about 9-11mpg depending on my moods lol) When the engine is running can you hear a kind of whistle/air moving sound that is in waves? This might be an exhaust leak and if severe enough can make milage horrible, I got about 6mpg's running no exhaust part of the summer. These are just some ideas from my experience.

 

So it's a regular cab and bed with 460. I started it with the hood open I didn't hear any whistling noises it sounded fine to me. It just doesn't seem right to me that a big truck would only get a 100 miles per tank. No matter the mpg.

 

Very common problem with fuel transferring from one tank to the other on these trucks. It's caused by a sticking or faulty shuttle valve in the tank that is getting filled. I suspect the front tank is filling the rear as you run down the road.

 

So what you are saying is when I'm driving there is a valve that is not closing all the way. So when I stop the gas will slush from the front gas container to rear one even though the switch in on the front tank.