Well, after about 100 more miles it didn't sound right. Idle was better, but 2500-3500 rpm sounded like it had a loose valve. After reading some posts about valve springs I opened her back up to check. The valve spring strength on #2 compares favorably with #3 so no problem there.
Then I began to suspect something with the rocker, shaft, or foot. I took them out and bingo! The cam lobe is worn and the rocker has an "interesting" profile. New guides and a valve grind was done about 2 years ago. There is a charge for "make piece for back of cam" which I believe was when he installed the 911SC cams.
I don't think there have been a lot of miles since that time as a month previous there were 90k miles on a reciept. There are currently 108k miles on the car.
So here's the big $$$ question. Where do I go from here? If the cam is lubricated by a faulty sprayer then I need to check/fix it. I don't know what the chances are of a single bad lobe on these cams, but not knowing the origin of the cams I am concerned.
Given that the rocker has a double cup profile now I suspect that one cup is the original cam's life and the second one was the SC cam wearing down. What else should I think about replacing when I go in to take care of this? The can of worms is now open...
