KJ sucking gas way too fast

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 8:56 am

Okay some background info on my KJ for those who do not know it...

2006 Jeep Liberty Sport
Auto transmission
2.5" Daystar Spacer lift on stock OEM suspension parts (besides the rear shocks)
16" Renny wheels with 245/75/16 BFG KM2s, Flowmaster Super 40 muffler and Fram air filter.
Removed carpet and rear seats...

SO my question:
Why is my KJ using up gas so quickly? Last night it was little under 1/4 of a tank and I put $50 init which put it little over FULL. I live 7 miles from town and from driving to the first light in town, to the Speedway 3 lights down, up to a turning lane to turn around and getting to the college not even 3 miles away...My KJ went from FULL to being in the middle of 3/4 and FULL!!! When I first got into town I turned O/D OFF. I was sitting at the light to around after I left Speedway and I look down at my gas gauge to see it had used 2 GALLONS just sitting there with O/D OFF!!!...I don't know if it's because I'm running Mud Tires or because I gased it to beat the traffic (leaving Speedway). My point is THERE IS NO WAY I could have used 4 gallons driving from my house, to Speedway and then to the college. Which is only 10 miles maybe?

I'm thinking my fuel filter maybe getting clogged up or there could be a different problem. I wanted to ask YOU ALL since some of you may have had this problem before. I'd hate to sell my Jeep because it's just being a gas hog! :evil:

PLEASE I WOULD LIKE TO SEE A REPLY TO THIS BEFORE THE END OF THEY DAY... :cry:

audiboy86 · **Posted:** Tue Mar 29, 2011 9:12 am

First of all do you smell gas anywhere? Because even with the heavy mud tires you shouldn't drop below at 15 miles to the gallon. Next of all when was the last time you changed your spark plugs? Because i know that my ex didnt change her about 30k and her mileage was horrible. After a quick Seafom i changed the plugs and the oil and you could tell the difference right away.

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 9:25 am

audiboy86 wrote:

First of all do you smell gas anywhere? Because even with the heavy mud tires you shouldn't drop below at 15 miles to the gallon. Next of all when was the last time you changed your spark plugs? Because i know that my ex didnt change her about 30k and her mileage was horrible. After a quick Seafom i changed the plugs and the oil and you could tell the difference right away.

Only time I smell gas is when im filling up or the gas trucks are filling up the gas wells at the gas stations. When I took out the carpet in the rear cargo area...I did notice that those welds had cracks in them...and when I turn my jeep on I can hear this whistling sound from the rear. From the muffler making noise

NewOldTimer · **Posted:** Tue Mar 29, 2011 10:04 am

When I first got my KJ back in October, I too was concerned that I was getting
only an average of 13 mpg with little, if any highway miles.
I accepted it as normal after reading the MPG forums, and didn't think anymore
about it until 3000 miles later when I changed the oil.

The place I went to said my fuel system was "quite dirt" and offered to use a couple
of products they had to clean out my fuel system, to the tune of $70!!!! :shock:

I politely declined, then went to the local auto parts store, and picked up a bottle of
fuel system cleaner for $8.00, poured it in the gas tank, & filled up.

My mileage has improved from an average of 13.5 to 15.8. :BANANA:

My plan is to add the fuel system cleaner at every oil change interval.
So far, the best $8.00 I've spent on the KJ.

audiboy86 · **Posted:** Tue Mar 29, 2011 10:23 am

Seafoam oil change and plugs if i was closer i woulc help you knock it all out in about and hour but now that you have tools enjoy your wrench time with your jeep

. And when you are done go out and drive it and wheel it. I don't believe to much in the intank fuel system cleaners but Seafoam poured in the intake is a once a year must on these motors.

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 11:09 am

NewOldTimer wrote:

When I first got my KJ back in October, I too was concerned that I was getting
only an average of 13 mpg with little, if any highway miles.
I accepted it as normal after reading the MPG forums, and didn't think anymore
about it until 3000 miles later when I changed the oil.

The place I went to said my fuel system was "quite dirt" and offered to use a couple
of products they had to clean out my fuel system, to the tune of $70!!!! :shock:

I politely declined, then went to the local auto parts store, and picked up a bottle of
fuel system cleaner for $8.00, poured it in the gas tank, & filled up.
E
My mileage has improved from an average of 13.5 to 15.8. :BANANA:

My plan is to add the fuel system cleaner at every oil change interval.
So far, the best $8.00 I've spent on the KJ.

The last fill up before this I bought a STP fuel injection cleaner. Cost like $3 and it helped abit. I just had the tranny and diff fluids changed last week so the jeep is running AND shifting better. I'll check all of my tires for low tire pressure. Seems like one of my tires had thump thump feel this morning. I did take off the rear tire carrier but I doubt that would decrease mpg. Another thing, when I took off my front doors; my gas needle hardly moved! :shock:

Either my gas gauge is hooked up through the driver door or I get better mpgs without the front doors.

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 11:16 am

audiboy86 wrote:

Seafoam oil change and plugs if i was closer i woulc help you knock it all out in about and hour but now that you have tools enjoy your wrench time with your jeep

. And when you are done go out and drive it and wheel it. I don't believe to much in the intank fuel system cleaners but Seafoam poured in the intake is a once a year must on these motors.

Well thank you for offering to help wench on my jeep

Even though I have my own LIMITED tool supply I still do not know how to work on it(mechanically).

Maybe that fuel injection cleaner caused the problem :?:

Another thing... When I drive around 60-65mph, I get better mpgs than if I drive the speed limit.

Does mean I should regear to 4.10s this year instead of redoing my lift set up? I find it awkward to compensate my awful mpgs that i have to speed to get decent mpgs...

What do you all think?

LibertyCRD · **Posted:** Tue Mar 29, 2011 2:59 pm

I think you should put 150 or 200 miles on it, fill it back up, and see how many gallons it takes to fill it. The KJ fuel guage is notorious for being innacurate. My wife's 3.7L KJ was way off. It would show empty sometimes with several gallons left in the tank. She could run it to "E" on the guage, fuel light on, and then fill it up and it would only take 13 or 14 gallons to fill it up (it's a 20.5 gallon tank)! So the guage, BCM, cluster communication is wack-O on those Jeeps sometimes.

I'd hand calculate your mileage by seeing how many miles you are actually getting on X number of gallons and then we can go from there and figure out the cause. Your mileage might not be as bad as you think.

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 3:10 pm

LibertyCRD wrote:

I think you should put 150 or 200 miles on it, fill it back up, and see how many gallons it takes to fill it. The KJ fuel guage is notorious for being innacurate. My wife's 3.7L KJ was way off. It would show empty sometimes with several gallons left in the tank. She could run it to "E" on the guage, fuel light on, and then fill it up and it would only take 13 or 14 gallons to fill it up (it's a 20.5 gallon tank)! So the guage, BCM, cluster communication is wack-O on those Jeeps sometimes.

I'd hand calculate your mileage by seeing how many miles you are actually getting on X number of gallons and then we can go from there and figure out the cause. Your mileage might not be as bad as you think.

Back in the day when gas was ohhh $2.49...I had to be really carefully when I did fill up my Jeep. Because it wouldstill over flow even when it kicked off. I'm thinking bad sensor somewhere. But now I don't worry about that since it takes every dime I have to fill it up. I reset my trip meter (the things that counts the miles you drive). So when my Jeep is on EMPTY I'll look at that Trip Meter and see how many miles I went on a full tank. May not be the most accurate way, but seemed to be the easiest way for me. Sometimes, I think I get paranoid too much about my Jeep. And with my pockets running low on cash, I'm just nervous. and anxious to find out if I get unemployment next week or not. Until then, my nerves will be SHOT! :shock:

infernicus · **Posted:** Tue Mar 29, 2011 3:35 pm

I usually fill up at a half a tank.
Now I've been waiting until 1/4 of a tank.
I usually get around 300 miles to a tank.

300 miles driven/20.5 gallons to fill up=14.6 miles to the gallon.

Measuring the whole tank is the most accurate, or at least a half a tank and do the math yourself to see how many miles you have driven and how many gallons it took to fill up. The 3/4 to full portion is never accurate.

blackwidowkj06 · **Posted:** Tue Mar 29, 2011 3:53 pm

infernicus wrote:

I usually fill up at a half a tank.
Now I've been waiting until 1/4 of a tank.
I usually get around 300 miles to a tank.

300 miles driven/20.5 gallons to fill up=14.6 miles to the gallon.

Measuring the whole tank is the most accurate, or at least a half a tank and do the math yourself to see how many miles you have driven and how many gallons it took to fill up. The 3/4 to full portion is never accurate.

When gas was $2.49 I did the same thing...fill up at half full. But I realized that was costing me way too much. Since then, I have lost my job in Jan. '11 and have beeing waiting since then to find out if I get unemployment in April. Because of loosing my job, I've cut back on driving soo much and going on spare-of-the-moment offroad drives. I've been living off what Financial Aid was left over from the college getting their cut. Got that money back in late Feb/early March. So far I've done really good, but now I'm getting low low on money. Partly because it's taking $40-$50 each time to fill up my Jeep. OH, and I can't forget the $1,000+ in bills I had to pay in one month :dizzy:

Man, I really do miss the $2.49 gas prices. $20 would go a long ways for me on that price.
I've done already what most of you have mentioned, except the SEAFOAM thing. Which I have NO CLUE about.

Sparks plugs(check), new air filter(check), fuel injection cleaner STP (check), regular oil changes (check)

Anything I've missed that could cheaply be done? I mean my Jeep has 63,350 miles almost. Do any of you think it's about time for a new fuel filter? I know that will cost an arm and a leg. I'm due for another oil change in about 500 miles. Thinking if I use some GUNK REMOVER before I take it to the dealership to have the oil changed, that MIGHT help. I haven't done that in awhile and probably needs it. :shock:

P.S. I only go to the dealership to have my oil changed because when you buy a vehicle from the Jeep Dealership where I live, you get FREE OIL FOR LIFE. Which means you only pay for the oil filter Only costs you $6.36 in the end.

Khaki-KJ · **Posted:** Wed Mar 30, 2011 12:03 am

I did not see it on the list of things you have changed, but did you change the PCV valve? If it is gummed up it can also affect your mileage. They are pretty cheap to replace, around $5.00 +/-.

blackwidowkj06 · **Posted:** Wed Mar 30, 2011 12:25 am

Khaki-KJ wrote:

I did not see it on the list of things you have changed, but did you change the PCV valve? If it is gummed up it can also affect your mileage. They are pretty cheap to replace, around $5.00 +/-.

Nope and don't know how.

I know they're cheap and easy to fix but lime I said I have no clue how to...I don't even know where the thing is!

Khaki-KJ · **Posted:** Wed Mar 30, 2011 10:12 pm

The rubber hose might be a little hard to get off if the PCV has not been changed in a while. It takes about 5 minutes to make the change.

I copied this from the service manual;

PCV VALVE
REMOVAL
The PCV valve (6) is located on the oil filler tube (4).
Two locating tabs (2) are located on the side of the
valve. These 2 tabs fit into a cam lock in the oil filler
tube. An O-ring seals the valve to the filler tube.
1. Disconnect PCV line/hose (5) by disconnecting rubber
hose at PCV valve fitting.
2. Remove PCV valve at oil filler tube by rotating PCV
valve downward (counterclockwise) until locating
tabs have been freed at cam lock. After tabs have
cleared, pull valve straight out from filler tube. To
prevent damage to PCV valve locating tabs,
valve must be pointed downward for removal.
Do not force valve from oil filler tube.
3. After valve is removed, check condition of valve
O-ring (1).

INSTALLATION
The PCV valve (6) is located on the oil filler tube (4).
Two locating tabs (2) are located on the side of the
valve. These 2 tabs fit into a cam lock (3) in the oil
filler tube. An O-ring seals the valve to the filler tube.
1. Return PCV valve back to oil filler tube by placing
valve locating tabs into cam lock. Press PCV valve
in and rotate valve upward. A slight click will be felt
when tabs have engaged cam lock. Valve should
be pointed towards rear of vehicle.
2. Connect PCV line/hose and rubber hose to PCV
valve.

BugginKJ · **Joined:** Mon Jul 06, 2009 7:35 pm **Posts:** 4576

On an 06 Liberty the PCV valve is located at the left rear (drivers side) of the engine behind the valve cover, it looks like a large nut sorta with the hose going to it.

blackwidowkj06 · **Posted:** Wed Mar 30, 2011 11:36 pm

I looked at the trip meter on the dash to see how many miles I had driven from a full tank to 3/4. Counting the miles from my house to town before I reset and after I reset I would say it was 30ish miles :shock:

That's not good at all guys, so something is wrong. I'm guess my gas gauge is off :?:

Then in the rear cargo area there looks to be like multiple welds and cracks in between them.

When I start my Jeep, automatically I can hear this whistling noise coming from the rear. Well it's those cracks. Some how air/sound is coming up through them. Also where
I removed the carpet from the rear cargo area, there is a gap between the middle plastic piece and the metal. It's right up against the tailgate when you shut it. I'll get pictures of both tomorrow to show you all so you'll know what I'm talking about.

Might be selling my KJ in the end because I'm trying to finish my last year of college without working so I can do really good. Good Jeep and I really do like; but gas is killing me! Seems I do better on long distances than short :dizzy: Wish I lived 30 miles from town instead of less than 7 miles (like I do now) Maybe I'd get better MPGs then! But counting the 10 miles of driving on country roads and an additional 5 miles on a highway to GET to the main highway (US 27). My logic probably wouldn't work.

Find out if I get unemployment next from being laid-off in January from my job. The decision to keep the KJ or not will come next week.

blackwidowkj06 · **Posted:** Thu Mar 31, 2011 12:33 am

Think I know the cure...

Take the KJ off-roading!!! Seems to do better after a nice run :wink:

Khaki-KJ · **Posted:** Thu Mar 31, 2011 1:34 am

BugginKJ wrote:

On an 06 Liberty the PCV valve is located at the left rear (drivers side) of the engine behind the valve cover, it looks like a large nut sorta with the hose going to it.

I have an 06 and the PCV is right where it says it is in the service manual, on the neck of the oil filler.

tjkj2002 · **Posted:** Thu Mar 31, 2011 9:38 am

BugginKJ wrote:

On an 06 Liberty the PCV valve is located at the left rear (drivers side) of the engine behind the valve cover, it looks like a large nut sorta with the hose going to it.

Only for '07+ 3.7's.

Watch out using seafoam,it's far to harsh for the plastic intake manifold.

blackwidowkj06 · **Posted:** Thu Mar 31, 2011 10:45 am

Went to O'Reilly's today...they man Tony who helps me with my Jeep parts and such; hooked the computer up to it and it said there was nothing wrong with it. I showed him the milege my trip meter said and what my gas gauge said. Miles before resetting+miles after was roughly 60 miles and my tank said it was on 3/4 of a tank :shock:

Tony said there was no way my Jeep could use that much gas within a short distance.

He told me someone has been stealing my gas. I ordered a PCV vavle and he's going to put that on for me tomorrow. I also will be buying a locking gas cap as well. After my last class I'm going back to O'Reilly's to have him drive my Jeep and see if he can tell if anything is wrong otherwise. BlackWidow will STILL be :JEEPIN:

KJ sucking gas way too fast

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