2001 Suzuki Vitara

Engine Cooling problem
2001 Suzuki Vitara 6 cyl Four Wheel Drive Automatic 142000 miles

I have a 2001 Suzuki Grand Vitara 4x4. I have changed the water pump, thermostat, sent it to a radiator shop and changed the fan. It keeps overheating and the water of the backflow container keeps flushing out and the truck is burning through a quart of oil within a week. Mechanic says we need to remove the engine to change a gasket but it would be a lil costly to do that and it not be the problem. If you can please tell me of any other possibilities.
April 15, 2010.

Get it block and pressure tested to rule out the headgasket cracked head or block and intake leak

Apr 15, 2010.