How to Replace the PCV Valve
2004-2009 Toyota Prius
I've replaced this part on both of our Prii now and have used two different methods. The first one I did by the book (repair manual) and it was a pain. I did a little more research for my next replacement and found an interesting PDF outlining how you don't need to remove the wipers and upper pan. This tutorial uses the latter method since it's much easier and takes much less time. 60k is the recommended replacement interval for this but on both of my Prii I replaced them over 100k and they were just fine. This is best replaced along with the spark plugs since the same parts need to be removed. You could also combine this with a throttle body and MAF cleaning since access is super easy.
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- Socket wrench set
- Torque wrench (20-200 in-lbs)
- Torque wrench (10-80 ft-lbs)
- Box wrench set
- 2lb dead blow hammer
1) Remove the 2 10mm bolts circled in red. 74 in-lb (8.4 Nm, 86 kg-cm). Use a piece of wire or string to hang the relay block from the hood out of the way.
3) Remove the 4 10mm bolts circled in red, 80 in-lb (9.0 Nm, 92 kg-cm). Next disconnect the 4 ignition coil wiring harnesses (top) and the 4 fuel injector wiring harnesses (bottom), highlighted in green.
4) Pull the tab on the right of this wire harness clamp OUT (towards the front of the car) and then slide it off the holder to the right. You must remove this or you will not have the clearance for the next steps. The tab doesn't need to be pulled out too much either.
5) Pull the wiring harness up as shown.
6) At this point you can finally see the PCV valve as indicated by the blue arrow. Pinch the hose clamp and move it to the right. You can then pull the hose off the PCV valve.
7) Use a 19mm box wrench to remove the PCV valve...easier said than done! There is very little room to work here and the clearance that goes around the PCV valve is pretty small. I got this standard Craftsman box wrench around it fine though. The PDF says to use a ratching 19mm wrench but that's not neccessary, it would just allow you to not have to remove the wrench a few times. Leverage is the next problem. Chances are it will be pretty tough to get it loosened up. What I did is tap my dead blow hammer on the end of the 19mm wrench and it loosened up without much fuss. If you're not taking a one-handed photo like me you will be able to move the wiring harness out of the way a bit more than this pic shows.
New vs. old. Old was not stuck at all.
8) Apply anti-seize to the threads of the new PCV valve.
9) Install the new PCV Valve. 20 ft-lb (27 Nm, 275 kg-cm). It's pretty much impossible to get a torque wrench in there so I just made mine tight, but not over tightened.
10) Install remaining parts reverse of removal.
- PCV Valve Replacement on PriusChat.com, this is the by the book method.
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