One problem related to engine failure has been reported for the 1996 Lexus ES300. The most recently reported issues are listed below.
Engine failed (seized up) due to oil sludge, despite the fact that the car's oil had been regularly changed. In fact, the car's oil was changed every 3-4,000 miles, not every 5,000 as recommended by Lexus. Car was also completely serviced by Lexus at 70,000 miles and they obviously didn't look at the engine very well . . . There must have been evidence of sludge by that time.