Lexus Troubleshooting Questions? Ask a Lexus Expert
Hello Bill and thank you for your question,Are you feeling this vibration in the seat or the steering wheel or can you tell?
I do not suspect this vibration is caused by a bad timing belt. If anything I would suspect you may have a bad engine mount or a bad drive axle and I would start with having these checked first. One or both being worn can cause this type of vibration.