the valve is on lower side of engine near fire wall.
The PCV valve on a 1997 Toyota Avalon is located on top of the engine. It connects the left valve cover with the intake.
A cloud
The PCV valve is located on top of the valve cover in the middle.
On the valve cover, with a large vacuum hose attached
The EGR valve in a 1997 Nissan Altima is located at the top of the motor in a position near the firewall. The EGR valve is held in place by a vacuum line and 2 nuts.
like a boss
The engine is building up back pressure which forces oil into the breather. Check the air inlet hose and see if it is pulling a vacuum. If not you will need to clean it and replace the PCV valve.
A vacuum leak or a faulty IAC (Idle Air Control) valve.
Not familiar with that term for a Rav4. What are you trying to do?
Not sure which valve you are talking about, but it sounds like a vacuum check valve. If so, that's easy...air should flow one way and not the other...just blow in both ends to see if you can.
You have to install the thermostat with the jiggle valve in the 12 o'clock position.
if its a3.3 engine its located at the back of the planum, follow rubber vacuum hose comming out of the valve cover to the PVC on the planum