Mobil 1 5W30: Annual Protection Vs Extended Performance Vs Advanced full synthetic


The hose exiting the valve cover adjacent to the oil fill cap seems to be the main vent and it should be checked to make sure it is not restricted or have any leaks.


From this picture, it is part #9 (pipe breather) and #11 (Tube, Breather):
#5 is what connects to the PCV
#6 - not applicable to my car - it is ā€œLā€ shaped as you mentioned originally

#9 is mostly metal) but there are tubes connected - that is where some damage - a friend put a tape over. Discontinued part.

If you say any of these are very critical, I would change them before my next SMOG?