Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Positive Crankcase Ventilation: Service and Repair


1. Check hoses and connections for leakage or clogging.
2. Disconnect PCV valve from breather chamber, then start engine and run at idle.
3. Place finger over PCV valve and listen for clicking noise. If there is no clicking noise, replace PCV valve and repeat steps 1 through 3.
4. Install PCV valve, large end down.
5. On models equipped with blow-by filter, proceed as follows:
a. Ensure filter does not allow oil to drip or seep through. Replace filter as required.
b. Ensure filter is not clogged and covered with dust or dirt. Replace filter as required.