I experienced a problem that may be the same problem as the Lexus valve spring problem, or related to it. The mechanic said it was caused by a design flaw. Here is part of a letter I sent to Lexus in March 2010: I own a 2006 Lexus IS350, which I had been very happy with until February 1, 2010. As I was driving to work, there was a loud noise from the engine and the dashboard lit up with warning lights. I pulled over, read the owner"S manual, and drove to a Lexus dealership. The four year old car only had about 27,000 miles on it. Unfortunately, my warranty ended in December 2009. Since it was a Lexus, I wasn't expecting a major repair, but that"S what I got. The mechanic explained to me, that because of the engine design, it does not burn off carbon from the gasoline. The carbon collects in the engine, interferes with the valves and causes a misfire. I was told my 6 cylinder car only had 5 operational cylinders. The total cost to fix it was $995.20. I never received a response from Lexus. An apology would have been nice. The mechanic informed the consumer she will need to get the carbon cleaned out of the engine/fuel system on a regular basis, otherwise she would continue to experienced cylinder misfires. Updated IVOQ 12/01/10

- Lorton, VA, USA