my buick does that 1 qt every 5K Im bad about posting info that is not needed but searching the GM DVD i foudn this and it applies to the 2004 3.8 engine so jsut the fact this exist may say there is a potential problem.
Adm Msg - 2004 Grand Prix, Bonneville, LeSabre, Park Avenue Impala with 3800 Engines - Excessive Oil Consumption #VSS20040234 - (Aug 26, 2004)
2004 Grand Prix, Bonneville, LeSabre, Park Avenue, Impala with 3800 Engines - Excessive Oil Consumption
2004 Buick LeSabre, Park Avenue
2004 Chevrolet Impala
2004 Pontiac Bonneville, Grand Prix
The following should be considered when diagnosing oil consumption complaints of more than 1 qt in 2,000 miles. This information is based on powertrain observation, analysis and findings of engines returned from the field for excessive oil consumption:
Perform an oil consumption test as outlined in Corporate Service Bulletin Number 01-06-01-011A.
Check the PCV system. Remove the PCV valve and verify that no components are missing. Check all the O-rings for nicks or cuts. Replace any components that are missing or damaged. Perform another oil consumption test IF any components were found to be missing or damaged.
Perform a cylinder leak-down test using J 35667-A. Follow the instructions provided with the tool and record leak-down of all cylinders. Leak-down rates should be between 12-18%. Cylinders with 30% leakage or greater are considered defective and will require service.
With all 6 spark plugs removed, note the coloration and condition of the spark plug electrodes. Note any unusual coloration, electrode build-up or oil on spark plug threads. Oil on plug threads generally indicates a valve seal/guide issue.
Visually inspect the valve seals for proper installation. Improperly installed valve seals can and will create an oil consumption issue. The intake valve seals are colored blue (and have the letters "IN" molded into the top of the seal) and exhaust valve seals are colored light green (and have the letters "EX" molded into the top of the seal).
Evaluation of engines recently returned from the field for oil consumption concern revealed one consistent concern of exhaust valve seals not fully seated. If the valve seal is detected to be out of position, correct this condition by simply pushing down on the seal until it seats properly.