Some owners of 2005 Buick LeSabre or Park Avenue models may comment on excessive engine oil consumption on 3800 Series II and III engines. The condition may be caused by the retaining ring on exhaust valve stem seals not securely holding the seal on the cylinder head boss.
The exhaust valve stem seal(s) may move off the boss, no longer providing a sealing function between the exhaust valve stem and the valve guide.
Remove the engine valve rocker arm covers, the exhaust rocker arms and the exhaust valve springs to inspect the seals.
NOTE: Oversize valve stem seals are available. Make sure that the correct valve stem seals are installed. An oil consumption problem can be created by installing oversize seals.
The oversize seals are marked black in color and are not to be used unless installing valves with oversize stems. Exhaust valve seals are green in color and have “EX” molded into the top of the seal. Intake valve seals are blue and have “IN” molded into the top. The correct seal usage on all valves should be verified while checking for correctly seated exhaust valve stem seals.