Hmmm? Didn't do that right away? PCV system, sludge? Oil return from valve covers? Runs well so this may work out.
Perhaps slow cleaning (I don't like oil flushes - too fast!) with just one oil change with a qt of ATF and dump it the same day for a regular oil change with filter - go cheap but with SAE ratings for new cars and dump that after 500-1,000 miles depending on how fast you add up miles and then switch to a synthetic 10-30 - new filter again and it just might snap out of it.
I'm basing that on sludge and some varnish being a problem. Taking a valve cover off for inspection would tell better what the state of the state really is...... Just an idea,
T
Tom Greenleaf - MetroWest Boston - USA
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