from wikipedia : "Additionally, oiling problems were common, and added to the poor reputation of the North American 2.9. Although these problems mainly affected poorly maintained or high mileage engines, it occasionally affected low-mileage engines with proper maintenance as well. The symptom of these problems is serious valve train noise. This is due to a number of design faults. Valve train oil pressure was entirely dependent upon a supply fed through the two center cam bearings. Even slight bearing wear could cause complete loss of oil pressure to the hydraulic valve lifters, rocker shaft, and rockers. Excessive internal "bleeding" through the half-moon camshaft thrust plate also contributed to this, though this can possibly be remedied by reinstalling the thrust plate in an upside-down position."
google 2.9L v6..this explains why 2.9's "tick". I wonder if the 2.9's in the Merkur scorpio cars have this problem? last time i was at the junk yard i saw a couple of them.. made me go "hmm..."