I don't know whats going on but over the last 6 months or so my gas mileage has been dropping consistently. It's an all stock 2000 Cherokee w/ 155k. Aside from the mileage it runs fine. I made it 100 miles before having to fill up this time and thats driving extremely conservatively. I first noticed this 6 to 8 months ago when i started getting 12 mpg w/ mixed driving and has now dropped to about 6 mpg mixed. Any ideas?
6 mpg on stock Cherokee 4.0
- Thread starter jbarada
- Start date
TheGhost45
New member
Just spit balling ideas here but fuel pump maybe? Or perhaps your engine is extremely full of sludge and carbon and all that other fun stuff that builds up in your engine that eats the **** out of gas mileage.
Is your check engine light on?
See if you can pull some engine codes from it using this:
http://www.jeepz.com/forum/reference/21652-chrysler-engine-codes-late-1990s-up.html
See if you can pull some engine codes from it using this:
http://www.jeepz.com/forum/reference/21652-chrysler-engine-codes-late-1990s-up.html
Dakotanative
New member
Could be a brake dragging or a bearing that has went south. Put it on a very slight grade and see if it rolls. I would think the thing would be running like crap if the gas useage was a fuel problem. Maybe you have a small fuel line leak that only occurs when the pump is running. Do you have better mileage if you drive a hundred miles in one shot vs 10 miles 10 times? Does the vehicle fire off as soon as you hit the starter cold or warm?
No check engine light. I use it mostly to drive 10 minutes to and from work. It does seem to do much better on long trips. Usually about 15 to 17 mpg on the highway, but only 6 in town. It rolls on any slight grade, so i don't think it's brakes or bearings. It usually fires right up w/ no problem. Is it possible it could be leaky injectors?
TheGhost45
New member
If it was leaky injectors I'm almost 100% sure you would smell it.
FloridaCherokee1988
New member
Could be a vacuum leak as well, does it idle high or low at times? I know I lost a vacuum line on the trail (didn't notice it) and my gas mileage went way down in the city. Replaced the $2 line and my city mileage is back up to its normal 14 lol but my engine idled high which is what tipped me off.
Are you relying on a computer or are you manually calculating MPG?
FloridaCherokee1988
New member
Ya i'd try to hunt down and fix that vacuum leak and go from there, who knows it might fix it but atleast its a lead.
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