13 mpg??? WTF

[bmwnvue]

I am a new member on here and because of some issues with the site, I have yet to post my problem.

here goes,

the car is a 2003 Vue with the 3.0l.

long story short, I am getting about 100 to 115 miles on a half a tank. I know I know the first thing to check would be the air filter but the air filter is fine its a brand new K&N so we are good there. Then on to the plugs and wires, pulled the plugs and they are in surprisingly good shape seeing that the car ha 65k on the clock. Then on to the fuel system which I found out that when it was under warranty, it had a full fuel system service and the throttle body was cleaned. But finding that little bit of info left me with no where to turn. I have no clue why I am getting such crappy gas mileage. I thought it might have been a tank of bad gas but this has persisted for four tanks now.

please help me out.

Thanks

bmwnvue

[davidsky]

It might have codes if it's running poorly enough to cause poor fuel mileage.
Any excessive smoke?
Maybe it's leaking?
Someone stealing your gas?
How far can you go when you fill the tank up? It's best to determine fuel mileage the proper way.
1. Fill tank til it clicks
2. Reset trip odo
3. drive around til you need gas
4. Go back to same pump and fill tank til it clicks
5. divide mileage on trip odo by amount of gas you just put in the tank. Make sure you add the partial amount too. Don't round up or down.
6. Do that for several weeks or months to determine actual fuel mileage.

[sblarson]

Did the mileage drop happen all at once, or has it been a gradual decline?
Is the car running OK otherwise (idles OK, hard accel OK, no idiot lights)?
Do you smell gas at all?

Check the tires (though they'd probably have to be completely flat to get that mileage)!
Check the brakes to make sure you don't have a caliper sticking or something.

[bmwnvue]

It might have codes if it's running poorly enough to cause poor fuel mileage.
Any excessive smoke?
Maybe it's leaking?
Someone stealing your gas?
How far can you go when you fill the tank up? It's best to determine fuel mileage the proper way.
1. Fill tank til it clicks
2. Reset trip odo
3. drive around til you need gas
4. Go back to same pump and fill tank til it clicks
5. divide mileage on trip odo by amount of gas you just put in the tank. Make sure you add the partial amount too. Don't round up or down.
6. Do that for several weeks or months to determine actual fuel mileage.

No excessive smoke, and I thought too that someone might be stealing my gas so I bought a locking gas cap and the problem persists. I was also thinking that it might be leaking but from where??

thanks

Taylor

[bmwnvue]

Did the mileage drop happen all at once, or has it been a gradual decline?
Is the car running OK otherwise (idles OK, hard accel OK, no idiot lights)?
Do you smell gas at all?

Check the tires (though they'd probably have to be completely flat to get that mileage)!
Check the brakes to make sure you don't have a caliper sticking or something.
it dropped all at once. All of the sudden it just started getting ****ty gas mileage. One tank went for 320 and the next tank didnt even hit 270 and its been like that for three tanks now


Taylor

[VUE TO KILL]

Check your tires...Low air?

Change in driving style? I know a guy who used to rest his left foot on the corner of the brake pedal, causing a bit of brake drag

[fdryer]

Just a small bit of info; if you're using a K&N oiled type of air filter this may ruin the mass airflow sensor (MAF) that may be causing the decreased fuel mileage. Early L-series owners tried this and slowly destroyed the MAF sensor's ability to operate due to the oil leaving the filter and depositing onto the delicate MAF element corrupting airflow measurement. An expensive lesson.

[DeliriousGA]

Just a small bit of info; if you're using a K&N oiled type of air filter this may ruin the mass airflow sensor (MAF) that may be causing the decreased fuel mileage. Early L-series owners tried this and slowly destroyed the MAF sensor's ability to operate due to the oil leaving the filter and depositing onto the delicate MAF element corrupting airflow measurement. An expensive lesson.Yep. Same thing has happened to several owners I have talked to with many different models of cars. The K&N oiled filter is fine at first, but when it's cleaned and re-oiled it is usually over-oiled and that starts causing the problems.

You may want to change your O2 sensors too. They are only designed to last around 60K miles and should be considered a normal maintenance item rather than waiting for a code that says it's gone bad. An O2 sensor can be malfunctioning but still within range for a long time before a code pops up. That can really mess up your fuel/air mix.

[chugchug]

I have a 2005 3.5L AWD it also gets 13 miles to the gallon. I have been told that since i only drive 7 miles to work and 7 mile home. It doesn't give enough time for the motor to warm up. Since you burn more fuel at warm up time. I just bought a K&N replacement filter, I have only went though 1 fill up since I bought it and still got 13 miles to the gallon. I will see how it goes on the next few fill ups. So how many miles do you drive to work

[bmwnvue]

yeah thats not the problem with mine. I do have the K&N oil type filter but I just bought a new one when the filter got clogged. I dont have the problem with the short commute. I drive 23 miles to and from work so the problem isnt that my car doesnt have time to warm up. I think I may look into the O2 sensor thing cuz that may be the problem. I hope to god that the oil from that damn K&N isnt depositing on the MAF sensor. I had a buddy that I work with and he had to replace his MAF sensor in his 99 chevy and it cost him $300 just for the damn sensor. So hopefully its not the MAF. I would kill myself if that happened.

thanks
Taylor