99 grand cherokee limited 4.7

by dean9021 - 4/3/10 11:24 AM

I need help please. I own a 99 g.cherokee with a 4.7 v-8.
I always got 16 to 17 mpg, over night it changed to 10 mpg. I changed plugs,o2s,air filter and had it scoped by a tech. he said 1 muffler clamp was leaking so i changed that. any ideas?
Also there is a noise that sounds like a marble rolling when i stop.
it is comming from transfer case area,I changed fluid with special fluid for quadra drive t-case. Thanks for looking