There actually is a fix to
There actually is a fix to the carbon build up. Your issues sound identical to mine with exception of the smell and low oil light. Those we have not experienced. The carbon build up is due to how the fuel on that particular motor passes through the valves. There is a kit that re-routes how the fuel is injected. It first has to undergo a chemical clean consisting of three different cans of solution. Ultimately these chemicals eliminate the carbon and glass like build up off the valves. The kit re-routes how the fuel is injected. Surprisingly, the mechanic charged only $400.00 for what exceeded six hours of work. I suspect that was a gift as they had done a top end cleaning 8,000 miles before. Lexus dealerships have since adopted this same procedure. As you experienced, Lexus is worthless kidding themselves and the customer regarding the carbon build up. If you want the name/supplier of the kit and technicalities, you can email me. Darthflex@aol.com