Recently our 2000 A6 4.2L has been having a warm start issue. It starts right up when it's cold but once the engine warms up it won't start up again for a couple hours. When I turn the key it does absolutely nothing. It doesn't try to turn over or fire. Once it's cooled down it fires right back up and drives great. There is no CEL and it isn't throwing any codes. I replaced the ECT today and it had no effect. Anyone have an idea?

 

It could be a problem with your transmission shift linkage. Next time this happens, put the car in neutral and see if it starts