My truck is burning oil like crazy. im always toping off in between oil changes up to 4 quarts. i dont see any oil leeks! its a 97 ford expedition 4x4 with a 4.6

check the dipstick but I suspect that with 6 quarts ( gallon and a half)in an already filled sump that takes 4 quarts max is trouble in itself
coming to a stop and shaking indicates a vacuum leak or problem injectors
take it to an accredited service center , have the oil level adjusted and have the fault codes read

buy 4 qt.
fill to top mark,
always buy extra oil, so you can keep it full , im sure any 92 burns oil,tad more than new.
or if you drive fast , it sure will burn more.
fsm quote 3.7qt

4 QUARTS W/FILTER CHANGE

There should be no less than 5 quarts of oil including what is retained in the oil filter. In some Ford Heavy and medium duty applications as in pick-ups and truck chassis based SUV's you will find it has a seven quart capacity.

Four quarts on 5000 miles is quite a lot. You should see white smoke from burning oil. If not then it's leaking out. After a trip top off the oil and place a sheet of cardboard under the van when parked overnight or longer. Then check the cardboard if there is oil on it it's leaking either from the drain plug or oil filter. Regardless always check your oil level and do not run it if it is low by any means. Also a visual check with a good light source should be done too. Feel the drain plug area and oil filter area for wet dripping oil. Be careful and don't do this when hot.
Good luck and I hope this helps
burdfrenzy
http://stores.ebay.com/Pittsburgh-Joes-Pants-Nat

Possible solution..Expedition uses a vacuum solenoid on the firewall that controls vacuum to the 4-wheel drive actuator. Vacuum "unlocks" the 4-wheel drive, so you may have a leak in the line to the actuator so the 4-wheel drive is always on. Seems backwards, I know.

change your oil and filter.try a oil designed for high mileage.caser oil and vavoline both make a good product.i hope this helps but your car is burning oil and ussually thats a mech failure. you might also try a premium oil additive like lucas. be sure that you dont over fill the crank case.for every quart of something you add you have to subtract a quart so the total meats factory specs

WIth that many miles, the most likely thing is that the rings are worn and oil is getting into the cylinders and being burned with the gas. If you're getting a bit of blue or grey smoke when you crank it up after being left overnight then it's absolutely this.

There's really nothing to be done about it short of rebuilding the engine but if it's otherwise running good I'd just be careful to watch the oil level and keep using it.

fill till over 1/4 over full usually 5.5 to 6 qrts

dirty or clogged lifters,either use an engine detergent or 1 quart of diesel fuel in the oil,idle only for about 20 minutes,then change the oil and filter and see how it is now.