I'll parrot the other guys - drop the filter, dissect it, drop the pan and pull the valve cover. Check the crank area for scores and watch for shavings and oddities near the connecting arm seats on the crank. Anything that resides near or has a bearing, check it if possible. Bearing jackets (housings) that are eating themselves due to wear and possibly poor lubrication / mechanical defects will "shave off". I've done that in the past with an old V8 that I inadvertently starved of oil @ 120 KM/H (crank bearings).
Daily driver 1: 2007 Jeep Wrangler Unlimited Sport "S"
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.