Lexus Troubleshooting Questions? Ask a Lexus Expert
Hello. Welcome to Just Answer. Please allow me to assist you. Engine mounts are absolutely critical to isolate the engine vibrations. When they get weak, or wear out, they collapse. This allows no resilience or isolation form the engine to the front sub-frame assembly. If you only replaced half of the mounts, you most assuredly need to replace the ones that were not replaced.