Nissan Pathfinder Engine Knock

Was Driving Down The Road And My Truck Cut Off. When I Started It Back Up The Motor Was Knocking From The Top Of The Motor.

After Starting Engine If You Rev It Up A Little An Upper Engine Knock Starts That Sounds Similar To A Rod Knock But Stops When It Drops Back...

Old Owner Ran Engine With No Or Low Motor Oil.i Replaced Sparkplugs And Did A Full Oil Change.