Chrysler Repair: Mysterious knocking in 86 2.2L turbo engine, valve cover gasket, chrysler new yorker

Question
Hi Mr Finston,

Thanks for hearing me on my question.  
I recently acquired a 1986 Chrysler New Yorker.  Car has a 2.2 turbo motor in it and has only 52xxx miles on it.

The car had been sitting for some time but drove extremely well.  When I bought it the 1st thing I did was change the oil.  With a car that had been sitting for time I expected it to start leaking oil.  But I started to go through alot of it.  Like a quart a week.  Mechanic says it has some minor leaks around valve cover and oil pan but not bad enough to justify a quart a week.  Turns out the turbocharger is leaking it.  So I decided to fix the smaller leaks...because I know howto do it unlike the turbo.  
I changed the valve cover gasket just a few days after plugs and wires.  Good news was the car no longer leaks there,  bad news was about 1 day later my engine started knocking.  I don't recall knocking anything into the motor when cover was off.  Seems to be a constant rattle that gets worse when under stress.  However when the car is idling in drive it sounds ok.  I took the sparkplug wires off one by one to see if there was any significant change and there was not.  The knock seems to be on top
I have changed the oil again since then and have kept the levels up.  
I know it is probably hard for you because you can't hear it but maybe some others opinion would help.

My father-in-law says it has a bad bearing on the bottom, but how would that cause the knock on top.

Thanks,
Paul

Answer
Hi Paul,
I would focus on the immediate preceding repair, the valve cover gasket. I wonder if anything could have been disturbed during that job? Is there any chance that the distributor could have rotated such as to advance your spark timing which would cause an engine pinging (pre-ignition) sound that might fit your description? It should read 12 BTDC at curb idle with the plug for the thermostat housing temp sensor disconnected, as far as I know but check the underhood sticker. Other than that it could be a lash adjuster that isn't getting enough oil to pump it up hard due to some dirt in the passageway that supplies it. Did you change the weight of the oil being used? I doubt it is a bearing all of a sudden and the location doesn't sound right. If none of these give you any results, you may have to remove the valve cover and test for the firmness of the lash adjusters. If you find a soft one you may be able to clean it out of any dirt that could be blocking the oil supply to it.  Also check the valve train for displaced rockers, etc.
Roland