I was working on the truck and noticed a strange new sound from the engine bay, like a rattling bearing. Thought it might be a alternator bearing going out, so I took a length of hose to pin-point the source and found it was coming from the PCV valve. You can feel the ball vibrating up and down in it.
This is not normal, right? The old one did not do this and when shook, you can feel the ball rattle in it, so it doesn't seem bad (even though it looks like it may be original
). Unfortunately, I've got a FrankenTruck, It's an '81 D150 with a '77 motor and a '75 Carb, and when you look up the different years you get different part numbers from $3 to $6.
Is there a functional difference in the PCV valves that might be causing this?