Lexus RX300 motor making ruttling noise and is not drivable on Lexus RX300

Some Lexus RX300 owners report experiencing a rattling noise from the motor that renders the vehicle undrivable, which may indicate serious engine issues. Common causes include a worn timing chain that produces rattling sounds, particularly after a cold start, and valvetrain problems characterized by ticking or clicking noises due to worn lifters or damaged camshaft lobes. Additionally, loose components such as heat shields or exhaust parts can lead to clattering noises, while a failed exhaust system may cause a rumbling sound. Owners experiencing these symptoms are advised to seek prompt inspection by a qualified mechanic to prevent further damage and potential engine failure.