Have an 850 GLT with about 100k miles on it. Have an oil leak that the repair shop has not been able to fix. First, they replaced the camshaft position sensor seal. Still leaked. Then they resealed the rear cover plate at the rear of the cylinder head. Still leaked. Now, they removed camshaft sensor and there was a puddle of oil sitting in the bottom ring. They said it's very unusual (of course) and there may be some problem within the camshaft. Does anyone have an idea what the problem could be?