While we are very fortunate with an all metal PCV valve, you should still take the time out to check and replace it as needed. This guide will show you how to remove, check, and replace the valve - and it is a very cheap and easy maintenance item.
Difficulty: Easy
Frequency: Check as needed
Estimated time: 15 minutes
Estimated cost: Using the genuine Toyota part (Aisan), the cost is around $5
Toyota OEM PCV Valve:12204-31110
MSRP: $6.79
Tools Required: 19mm deep socket, breaker bar, & flex head ratchet
Although you may not have a check engine light, replacing your PCV valve may help you prevent future problems. A PCV (positive crankcase ventilation) valve, is a critical one-way valve that allows unburned gases to be recirculated into the engine instead of building up into sludge or venting directly into the environment. So if the valve gets gummed up, the valve could be sealed closed and can cause rough idling and blown gaskets. To me, replacing a $5 part every few years is a no brainer.
To locate the PCV valve, take off the engine cover and look on the driver's side of the engine. Near the back, you will see the tubing connecting the valve to the intake manifold.
The spring clamp should not be super tight, like a transmission hose or coolant line. You should be able to easily squeeze the tabs and remove the hose from the line. If the clamp has dug into the tube, I recommend replacing the tube and clamps with OEM parts.
With a 19mm deep socket and breaker bar, loosen the PCV valve and remove by hand.
Upon removal, compare the valve with the new component. A good PCV valve should rattle and should be free of any gummy residue. This is not the only test for a PCV valve since there are springs inside, but if you remove it - I would just replace it. Its $5 after all and you can easily keep track of replacement intervals - check every year/check every two/etc. to maintain an ideal frequency without wasting money.
According to the Toyota Technical Information System (TIS), they recommend applying Toyota adhesive 1324/Threebond 1324 - I do not personally recommend this, especially if you are going to incorporate this into your maintenance routine. I also do not recommend using Loctite as a substitute either - remember, this is an aluminum block.
Reinstall the PCV valve to 20 ft-lb. Remember this is a valve and the hex of the valve should not be bottomed out against the block.
Reinstall the tubing and the spring clamp and you are done. Rest easy knowing that this small part is operating as it should and will save you from future problems.
