I have a 2007 f150 5.4 with 315000 miles on it

i Just started having a problem where I’m using 5x more fuel. At first I thought it was the gauge malfunctioning reading 2.4 to 7.4 mpg. I’ve noticed my fuel going down as well so that ruled out malfunctioning gauge. What I don’t get is the truck runs normal and there's no smoke or gas smell..

 

Are you basing it off the mpg indicator or did you do an actual manual calculation of gas mileage?

 

Post more info:

do you have codes?

How long have you owned, and what was it getting prior?

what were the last repair/mods/changes before you noticed this?

e-85?

 

Sounds like someone is filling their tank using your tank.

 

Absolutely
Something is bad wrong
If running that rich, you would not be able to drive it IMO
It would be belching black smoke and running like crap, flashing check engine light etc.

 

Suggest that you manually calculate MPG as follows:

1. fill up tank and record mileage
2. drive normally for 200 miles or more
3. fill up again and record mileage and gallons
4. subtract first mileage from second to get miles driven
5. divide miles driven by gallons to get MPG

 

I was having a P0345 so replaced the vct solenoid in bank 2 which cleared that code. It’s obvious now the two are not related. I’m thinking it could either be a pcm problem or a circuit board problem with the dash. I live on bumpy dirt roads so there’s always a lot of vibration and with as many miles as I have on it nothing would surprise me. One other thing . As soon as I put $20 worth of gas in it starting acting normal like 16 to 23 mpg which would lead me to think it’s a sender problem. My question is, is the gas gauge tied directly with the mpg gauge? Thank you for all your responses.

 

you need to obtain and share real actual data, see post 6, and report back with those details (the more miles and fuel you use in this exercise the more accurate the info/calculations will be).

until then, it’s not even clear if you have a problem with abnormal fuel consumption.

 

Use the same pump, same station & facing the same direction on the fill-ups for accuracy

 

^^^ Lol ^^^