I remember seeing somewhere saying that it will come back eventually. Doesn't seem right at all, but i guess it's something we need to replace from time to time.

 

Revival! What is the cost for the cam gear replacement? Mine is out of warranty and rattles at startup as well.

 

check out the site i went to dealer for this reason and this is the results they gave me...

https://www.clublexus.com/forums/can...rio-trash.html

 

My wife's IS250 started to sound like a diesel tractor on start up as well. Took it to the dealer and was told they could not replicate the problem and sent the car home. I did very little research, (ie a google search "rattle on start is250") and found the Toyota service bulletin on this. CAM GEARS!
Took the car back with the service bulletin and got it fixed. Car now had 72,000 miles and 4 years of age. Warranty on this issue was 70,000 and 5 years. After raising a stink, Toyota agreed to pay for parts, I still had to pay $600 in labor.
I have owned many brands of cars before this IS250. This one has been in the shop more than any other. My last car was an Acura Legend. We had it 14 years and put 200,000 miles on it. Other than routine maintenance, it never, ever broke down. Kinda wish I had stayed with them.