90-94 2.2l with sudden valve clatter

[tiki85westy]

All of the sudden there is valve clatter. I removed the valve cover and determined that the top (intake) valves are the quilty offenders. It is the hydraulic valve lashes in the rockers (non adjustable). I put different ones in, started engine and within a few minutes the clatter comes back. I changed the entire rocker assembly and again the same thing it starts quiet then gets bad with in a few minutes. I checked oil pressure and got 70psi at cold at idle. I ran a cleaning mix of 2 qts oil and 2qts ATF for nearly 2 hours, fresh oil and filter with no changes. Engine runs fine, loosing a bit of power but not much. THE QUESTION, What would cause this oiling problem (blockage) to the hydraulic adjusters on just the intake valves on one side on engine? Any way to clear a blocked oil passage with out full remoal and service of the head?
Thanks for any thoughts or suggestions

[tiki85westy]

Strange resolve to this unanswered question. I just continued to drive as I never found anything to fix, and Had plans to just change the engine. What I never said was that this 2.2 is in a 85 vw vanagon. I started the van the other day for my drive home and the ticking was gone. Three days now and no valve clatter. Wish I could explain how and why. Only thing I can figure is I managed to get a chunk of sealant, from changing and sealing the pan, in to the oil that was blocking an oil passage.