1. Attachments are working again! Check out this thread for more details and to report any other bugs.

How to Replace Gen II Prius Spark Plugs and PCV Valve

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Zedhomme, Oct 14, 2013.

  1. Zedhomme

    Zedhomme Member

    Joined:
    Aug 3, 2013
    227
    68
    0
    Location:
    Central Florida
    Vehicle:
    2016 Prius v wagon
    Model:
    Three
    I've seen some posts where people have removed the wiper arm assemblies and the cowl to replace the spark plugs and Vent Valve subassembly (PCV). This is not necessary, if you have or buy a tool. It's a 19mm reversible ratcheting combination wrench. I consulted the repair manual and replace my plugs and PCV with much less trouble. I'm attaching an Adobe pdf file of the process.
    Hope it helps someone save some money and get ready to enjoy the NEXT 120,000 miles.
    Here is the text version too. Costs are what I paid for OEM replacements at Toyota Dealer.
    PARTS: (4) 90080-91184, SK16R11 IRIDIUM Spark Plugs @9.70 =$38.80
    (1) 12204-21011 Valve Sub-assembly (PCV Valve) @ $9.12
    (1 packet) Anti-seize compound for plug threads. Buy a foil packet at auto parts store.
    Tools: Torque Wrench, Ratchet, 10mm socket, socket extension, 19mm reversible ratcheting Combination Wrench Cost $22 at Sears, PRICELESS to replace PCV Valve. With it NO NEED to remove wipers and cowl.
    STEPS:
    1) Remove Engine Room Relay Block (10mm socket), hang out of way w/bungie cord
    2) Disconnect Electrical Connector of MAF Meter from Air Cleaner
    3) Remove Air Cleaner Assembly, hose and 2 bolts (10mm socket) Cover Throttle Body Throat
    4) Disconnect Wire Harness (4 - 10mm bolts) Carefully move out of way.
    5) Disconnect fuel injector connector and Ignition Coils (10mm bolts). Check for water damage, cracks on coils. Prius has had issues with water running down the cowl and sitting on ignition coils causing damage and rough running.
    6) Remove Spark Plugs (16mm plug socket, rubber lined)
    7) Install new plugs, use anti-seize compound on threads. Can buy a packet at auto parts for about $1. Start threading new plugs by hand. Then, torque to 13 ft lbs.
    BONUS!! --Replace PCV Valve while these components are off. 19mm reversible ratcheting combination wrench (Tight fit)
    1) Disconnect Vent hose (Clamp)
    2) Unscrew Vent Valve, Replace, torque to 20 ft. lb. Really can't get a torque wrench in without removing brake master cylinder, but don't overtighten.
    3) Reattach vent hose.
    4) Reinstall components. Torque values are in pdf for most bolts.
     

    Attached Files:

  2. northcoaster

    northcoaster Junior Member

    Joined:
    Feb 12, 2010
    32
    2
    0
    Location:
    northcoast
    Vehicle:
    2006 Prius
    Model:
    N/A
    Thank you so much! does anybody have a video of at least part of this?
     
  3. N.J.PRIUS

    N.J.PRIUS Member

    Joined:
    Mar 23, 2011
    139
    49
    0
    Location:
    Fort Lee, NJ
    Vehicle:
    2013 Prius Plug-in
    Model:
    Plug-in Advanced
    Thank-you for posting this! I am at 111,000 miles and will be needing to do both of these procedures soon. A video would be great! Thanks again for posting this.

    My local Toyota dealer just quoted me $108.00 for spark plug replacement.
     
  4. Zedhomme

    Zedhomme Member

    Joined:
    Aug 3, 2013
    227
    68
    0
    Location:
    Central Florida
    Vehicle:
    2016 Prius v wagon
    Model:
    Three
    I didn't have time this weekend. I'll try and come up with one next weekend. It may be slightly abbreviated. Don't really want to pull all the plugs out again, but will try to do the majority of it.
     
  5. Chris Dragon

    Chris Dragon Junior Member

    Joined:
    Dec 16, 2012
    22
    6
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hi Zedhomme,

    Thanks for the guide!

    When you say "USE SOCKET WITH RUBBER-LINED 16MM PLUG SOCKET TO REMOVE AND INSTALL PLUGS TO
    AVOID BREAKING CERAMIC.", do you mean just use a normal plug socket adapter and add rubber? Like a bike tire tube, maybe? You should include those bits in your list of tools required.
     
  6. uart

    uart Senior Member

    Joined:
    Sep 7, 2009
    4,215
    1,200
    0
    Location:
    Australia
    Vehicle:
    2005 Prius
    Chris, the rubber lining (washer) is included as a standard part of most spark plug sockets. The main purpose of this rubber insert is to hold the spark plug firmly and allow it to be easily inserted or removed (from the spark plug well).

    BTW. A 5/8" spark plug socket will fit just as well.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    A further purpose of the insert is that it keeps the deep socket properly aligned with the spark plug to avoid damage to the plug. If you use a 5/8" or 16 mm deep socket without a rubber insert, it is easy to place the socket so that the plug is not exactly coaxial within, which will result in stress on the ceramic tail and some likelihood that the tail will break off.
     
  8. Chris Dragon

    Chris Dragon Junior Member

    Joined:
    Dec 16, 2012
    22
    6
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    Ah, cool. I was confused because the plug sockets I was looking at on Amazon never mentioned rubber, but maybe it's just assumed, or not all have it. This one does mention rubber. This one says it has a "rubber retaining ring" while this one says "rubber insert". I wonder if they're the same thing? "Rubber insert" sounds more promising.
     
    Okinawa likes this.
  9. neez

    neez Member

    Joined:
    Jan 9, 2014
    194
    37
    3
    Vehicle:
    2011 Prius
    Model:
    Two
    You aren't supposed to use anti-seize with plated plugs, like iridium. It's not necessary because the aluminum doesn't contact the steel, and the anti-seize acts as a lubricant allowing for people to over-torque the plugs. Generally all cars use iridium today, and you won't see any anti-seize on the plugs from the factory.
     
  10. MtBiker

    MtBiker Junior Member

    Joined:
    Sep 20, 2006
    26
    4
    0
    I'm considering buying this X-Beam design 19mm wrench for this job due to it's flat surface area in which to apply more pressure. I'm concerned though that this design might interfere with something during the plug change. Is there plenty of room for the X-Beam wrench or should I stick with the regular design? Thanks.
     
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The purpose of a 19 mm wrench is to remove the PCV valve. This adds no value regarding the spark plug change.
     
  12. MtBiker

    MtBiker Junior Member

    Joined:
    Sep 20, 2006
    26
    4
    0

    I know that. If you look at the two different wrench designs, the x-beam design has a wider shank profile when turning than the standard design and could interfere if there isn't enough room for it. I want to know if there's enough room, in whatever turning angle is available, to use the x-beam design to remove the PCV valve.
     
  13. Zedhomme

    Zedhomme Member

    Joined:
    Aug 3, 2013
    227
    68
    0
    Location:
    Central Florida
    Vehicle:
    2016 Prius v wagon
    Model:
    Three
    There is very little room to get a wrench on the end of the PCV and also not much room to turn it when removing the PCV valve unless you remove the master cylinder. That's why I opted for the ratcheting 19mm. At least you can get each small amount of turn much more quickly.
     
  14. DarkPri503

    DarkPri503 Junior Member

    Joined:
    May 1, 2013
    68
    12
    0
    Location:
    Salem
    Vehicle:
    2005 Prius
    Model:
    II
    Thank you for the write up guys. Got my plugs done in under an hour taking my sweet time :) I wasn't prepared for how dirty the throttle body was and will go back in for a go a cleaning it up. I opted not to change the PCV this go around, as this Prius hasn't shown any signs or symptoms of ailment yet! :)

    My next project will be the coolant and possibly 12v, though I'll have to check its myToyota service record as it was babied and lots of maintenance was done prior to needing it.

    Here is a shot if the plugs being pulled at 124k. They look incredible for that many miles, mostly in 100° AZ weather!
     

    Attached Files:

  15. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

    Joined:
    Jul 29, 2011
    3,159
    988
    0
    Location:
    Tucson, AZ
    Vehicle:
    2005 Prius
    Model:
    Four
    As usual, they look perfect still.
     
  16. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,464
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Those old plugs look so good, I'm tempted to ask you to send them to me............
     
    DarkPri503 likes this.
  17. DarkPri503

    DarkPri503 Junior Member

    Joined:
    May 1, 2013
    68
    12
    0
    Location:
    Salem
    Vehicle:
    2005 Prius
    Model:
    II
    Ha!

    I have a concern though. After driving it the past couple days, it doesn't seem as zippy :/

    I checked the gap and it looked okay, though I might have been look at it wrong (between .040-.050 I believe, using the old coin measurer) and the igniter coil didn't really click when pushed in. I couldn't find my torque wrench so I hand tightened. I'm wondering if any if these concerns could be causing the perceived loss of power?
     
  18. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

    Joined:
    Jul 29, 2011
    3,159
    988
    0
    Location:
    Tucson, AZ
    Vehicle:
    2005 Prius
    Model:
    Four
    Hand tight????? That's not near tight enough. You need to find a torque wrench. I think the gap is supposed to be 1.0 mm (check on that though).
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    ^ Just a couple of thoughts:

    A lot of the high end plugs warn against adjusting gap. They're set at time of manufacture, and are not adjustable. Check on website what your's say.

    This is one time I would have hunted high and low till I found the torque wrench. They're typically pretty low torque values specd. 15~20 foot pounds. A smaller torque wrench with that range is best.
     
  20. DarkPri503

    DarkPri503 Junior Member

    Joined:
    May 1, 2013
    68
    12
    0
    Location:
    Salem
    Vehicle:
    2005 Prius
    Model:
    II
    Sorry, hand tighten plus 1/4-1/2 turn more for snug fit.
     
    Mendel Leisk likes this.
  21. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,464
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II

    Hand tightening doesn't always seat the plug properly. Sometimes it's still not tight even if you give it an additional 1/4 or 1/2 turn. Did any of them feel loose after the 1/2 turn? Like you can give it another 1/2 turn without effort? When I don't have a torque wrench handy, I normally seat it using a wrench and then tighten it an additional 1/4 turn.