Unlikely a blocked return would cause this. You'd still get pressure to the bearing.
Originally Posted by stevodotorg
I did change the valve cover gasket 3 months ago, but shows no sign of leaks, is it possible something fell down in there during the process?
+1 on Zell's hypothesis of oil pump nut.
Gotta check all the others for pre-fail.
Last edited by Stinger9; 11-15-2012 at 10:20 PM.