One problem related to engine failure has been reported for the 2009 Lexus RX350. The most recently reported issues are listed below.
While driving in the very busy freeway, the car suddenly stopped without any prior warning or any signal. Upon Lexus dealer inspection, the cause was , bolts used to secure the variable valve timing control device can become loose, one of the bolts came out and caused the timing chain to break and it broke the engine head, causing the vehicle to stop while being driven. Lexus has not recalled the RX 350 models, however on September 3, 2013 Lexus has recalled is 350, is 350c and GS 350 vehicles for the exact same reason. My car has always been serviced at Lexus dealer. According to Lexus service department, there was no way for me to prevent this or to know. The sudden stop of the vehicle in the freeway as the result of this engine failure could have caused a major accident which was very life threatening. These engines has to be recalled for inspection and repair by Lexus. Lexus did not accept the fault even though they accepted to pay partial part of the cost of the rebuilding the engine as a courtesy.