One problem related to radiator has been reported for the 2008 Lexus IS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Lexus IS based on all problems reported for the 2008 IS.
It Is known as the valley plate leak. And it's radiator fluid leaking out which causes damage to the compression and also causes the vehicle to over heat easily. It happened when I let the car sit and started it and I noticed the valley plate started leaking.