Bring out the garlic and wolfsbane, I 'fixed' my flickering oil 
light this weekend.  Scenario:  '85 1.9l with a hot idle oil light flicker.  
Previous fix attempts:  new sender, 10-40 oil, 20-50 oil, always a 
Fram filter, no avail.

Current fix:   uhhhh, a VW oil filter (!!!) and a crankcase of 
Castrol 5-50 synthetic.  Now I won't even attempt to ascribe the fix 
to one or the other but the flickers are 100% gone.

I will grant this:  Yes, I must have border line oil pressure because 
many of you run any oil and Fram filters without the flickers.  Yes, 
synthetic oil (I'm so excited about the 5-50 wt!) is wonderful.  and 
yes, the VW filter was constucted of better materials (the sealing 
o-ring was much more substantial, overall 'feel' was better).

Folks, the rest of this thread is yours!