Hi,
I have a 200 ES 300 and had similar problems, due to "oil gelling" which eventually caused the engine to seize. Fortunatley Lexus has a program which replaced the engine free of charge. The coverage is for 8 years from the date of original pruchase, regardless of ownership/mileage. Take it to a Lexus dealer, or call Lexus.
Good Luck!
JamieVT