I bought this car late last year. The car was maintained by Bavarian Machine Specialties (HIGHLY recommended) in Houston for the past 8 years. All service intervals were followed religously. I noticed the noise back around March, but got around to doing the valves in early May. When I open an engine, I always check the valve clearances. In this case there were only a couple of valves that were slightly loose. I adjusted all the valves - the noise did not get any better or any worse. I have tried to pin-point the source of the noise witout success
The car, unfortunately, has an automatic. Considering the service history and relatively low mileage of this car, and the reputation of the big-six, I'm at a loss.
Thanks for your input!