Photo Essay - How To Replace Prius Spark Plugs

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Phildo, Mar 23, 2017.

  1. Phildo

    Phildo Member

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    I bought a 2007 Toyota Prius a couple of months ago that will most likely be converted into a taxi. Until then, it’s been used occasionally as a personal car.

    The Malfunction Indicator Lamp (ie MIL - the orange engine warning light) came on a few weeks ago. I checked for diagnostic codes at the time and got codes that related to spark plugs, so wasn’t excessively fussed about it at the time.

    Tonight I decided to fit new spark plugs. I went looking for Denso SK16R11 plugs but the only supply was a nearby Toyota dealership. They quoted me $A24 per spark plug, and even when I asked about a taxi trade price it only dropped to $A22 each (I should be paying around $A14 each). I went elsewhere and bought NGK IFR5T11 spark plugs for $A10.80 each instead.

    I started the night by checking for codes again. I got the following:
    P0300
    P0302
    P0304
    U0073
    U0121
    C2318

    The P030X codes relate to spark plugs, which is why I knew that it was time to change them. I also want to do any maintenance possible on the car now, as once it becomes a taxi I will have limited access to it.

    The C2318 code relates to a low charge in the 12v battery, but the car hadn’t been driven for a couple of weeks. I’m not yet familiar with the U0073 and U0121 codes.

    [​IMG]

    [​IMG]

    I bought this car at auction, and although the user manual has all the required stamps, there were no invoices for previous maintenance (ie meaning that I don’t know what’s been done on the car in recent years). The car currently has 147,688km on it (ie around 91,769 miles).

    [​IMG]

    This is the engine bay area. I replaced the air filter on the day that I bought the car. To access the spark plug area I started with removing the relay box.

    [​IMG]

    There are two bolts holding the relay box in place. I removed them both with a 10mm socket.

    [​IMG]

    Once the relay box has been moved to one side the four coils can be seen (ie one per spark plug).

    The coil with the white lettering was only put on recently. When I got the car it had another, incorrect coil there. The car ran, but the coil was taller than the others. I bought a secondhand coil and put it in.

    [​IMG]

    Each coil has a bolt holding it in place. These bolts also have a 10mm head.

    [​IMG]

    Once each bolt is removed the coils can be lifted out. On top of each coil is a rubber seal to keep moisture out of the spark plug cavity.

    [​IMG]

    I started removing the spark plugs. I used a 1/4” drive ratchet, a 150mm extension bar, a universal joint and then a spark plug socket.

    [​IMG]

    As I couldn’t find Denso SK16R11 spark plugs for an acceptable price I bought NGK IFR5T11 plugs instead.

    [​IMG]

    There is considerable debate about whether or not to put anti-seize on spark plugs. Until tonight I have never put anti-seize on a spark plug in my life, but I’m going to start to. Right now I have another taxi that is well overdue for replacement spark plugs, but the existing ones are seized in. I can’t get them out, and nor can a mechanic that I referred the car to. We’re stumped.

    I didn’t put the spark plugs in that car, but considering the difficulty it is currently creating I’m going to start putting anti-seize on spark plugs from now on. And remove then at least every 50,000km to make sure that they’ll come loose.

    I bought this bottle of Loctite 38650 copper-based anti-seize a while ago and never used it until now.

    [​IMG]

    The spark plug socket that I use is a Bikeservice BS9133 16mm Thin Walled Socket. I bought this to fit a KTM enduro motorbike as normal 16mm spark plug sockets don’t fit in the head cavity. The thin walls on the Bikeservice socket give the socket a thinner diameter than other sockets.

    That socket has a 3/8” drive but I used 1/4” stuff when changing spark plugs so have a 3/8” to 1/4” adaptor plugged into it.

    [​IMG]

    This photo shows the thin walls of the socket, and now this makes the socket thinner than other 16mm sockets.

    [​IMG]

    When removing sockets I remove the rubber part inside the socket as it makes it difficult to tighten sockets (ie the rubber tends to stay behind, on the socket). I use the socket to loosen each spark plug, and then poke a telescopic extendable magnet down to remove each spark plug.

    Or, you can retrieve each spark plug by poking a coil down and retrieving it (ie the spark plug will plug into the coil).

    [​IMG]

    The telescopic extendable magnet is also useful for retrieving nuts and bolts from distant corners after dropping them, which I sometimes manage to do.

    [​IMG]

    Toyota specifies 18Nm for the spark plugs (we use metric here in Australia) but subtract 20-30% when using anti-seize. I figured that I’d tighten them to 15Nm with my Snap-On TECH2FR100 digital torque wrench, but it was feeling too tight and I wimped out at 12.3Nm. I gave up on using the torque wrench and put it away for the night.

    The Snap-On digital torque wrenches vibrate as they approach the preset figure and then beep when they reach that figure.

    There is a smaller version, the TECH1FR240, which would have been much better suited for this. If I ever see a new-near one go cheap enough on eBay then I’ll buy it (as I did with this one).

    [​IMG]

    I then loosened the spark plug and retightened it with a 1/4” ratchet.

    [​IMG]

    As with the anti-seize, there is debate about whether or not to put dielectric grease in the coil ends. On another car that I have as a taxi (Ford Falcon) the coil rubber tends to stick to the spark plug, making the coil extremely difficult to remove. Using dielectric grease has helped with that, so I’m going to do the same with my Toyotas.

    [​IMG]

    The coil for cylinder 2 had some moisture on it, which would explain the misfiring when the car is cold.

    As mentioned, the car had an incorrect coil for number 2 when I bought the car. This meant that there was no seal at the top of the spark plug cavity.

    I like to keep my engine bays clean, so washed it on the day that I bought the car. Not knowing about the lack of seal on coil number 2, water would have gone down that cavity.

    [​IMG]

    I set the car to idle and left it running for around half an hour. I then removed the four coils and left the car as it was for another hour or so, to let any remaining moisture evaporate away.

    [​IMG]

    I then put the spark plugs, coils and relay box back in place.

    I put the spark plugs at the base of the windscreen, in matching order of which cylinder each one came from.

    [​IMG]

    Once I was finished with the engine bay, I took the spark plugs into my shed and had a look at them. Number 2 was darker than the others, presumably from misfiring as a result of moisture. The other three all looked the same as each other.

    [​IMG]

    The spark plugs that came out are NGK PFR5B-11. Although they did the job, they’re not considered to be the ideal spark plug for the Prius.

    [​IMG]

    Spark plug number 2 had corrosion from previous moisture.

    [​IMG]

    Whereas the other three spark plugs had no signs of any corrosion.

    [​IMG]

    I recently bought a Midtronics HYB-1000 Hybrid Battery System Analyzer. I still don’t know if it’s going to be of any long-term use, but at least it checks for diagnostic codes. I checked and there were no codes. I’ll drive the car around town for a couple of days and then check again.

    [​IMG]

    I checked on the display and saw that the 12v battery was showing 14.1v, which is fine. After the earlier C2318 code I was expecting to have to replace that battery, although I possibly still will anyway.

    [​IMG]

    I also have a Midtronics MDX-P300 battery tester, so decided to use that to test the 12v battery.

    My previous taxis have been Ford Falcons, and I use a SuperCharge MF50 battery in them. That battery is rated at 650CCA and 107RC. I find that once the battery gets below 600CCA it’s time to replace it as then I have problems with the onboard taxi equipment (ie it resets and stuffs up when the car starts because of the starter motor using all the power).

    [​IMG]

    The 12v battery in the Prius is rated at 325CCA, and tested at 384CCA (ie as good as new). I like how the Midtronics tester can print out the results. I write the date on each bit of paper and put it in the bag with the tester. Over time I can monitor the gradual wear of a battery, and replace the battery before it leaves a car stranded somewhere.

    [​IMG]

    And that was it. I’m still quite new to the Toyota world but it was late at night, I was doing this in the driveway and it started to rain. Later on I’ll tinker with, and maintain, a few other items in the engine bay.
     
  2. edthefox5

    edthefox5 Senior Member

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    Pretty good. Great pictures.

    Referring to the car that you can't get the plugs out get a Dewalt 1/4 inch
    Impact drill. Attach it to your same set up with the universal joint.
    Put it in reverse and apply mild impact. Just sit there mildly impacting it in reverse for a few minutes.dont blast it. Just bump it.
    The constant mild banging will loosen it up. Don't go full impact as it may strip it out. It will come out at full impact guaranteed but it may damage the threads.

    I always use anti seize. You have steel plugs and aluminum head.

    Only thing different I would have done is blow out the spark plug well with compressed air before pulling the plugs.

    And under the air cleaner box is a 10 mm throat clamp. If u remove box and then don't tighten it then u will have a lot of unmetered air in the system and car may run poorly.

    Lastly the mfd shot if the 14.1 volt reading of the battery is the charge voltage. You went one step to far. You want to see the voltage of the battery in ignition. Or just measure it in the morning with a DVM at the front jump points before u start the car.
     
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  3. valde3

    valde3 Senior Member

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    Good info.

    For the spark plugs coper anti-seize might not be the best option as the plug is nickel coated in the aluminum head. Nickel anti-seize (which seems very hard to find in stores) or aluminum anti-seize might be better option.
     
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  4. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Great write up and post. Thank you for taking the time to do that. The thing that always amazes me is how little wear there is on the electrodes. Irridium is an absolutely amazing metal for sparkplugs.
     
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  5. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Can you post a pic of what a Ford Falcon looks like in Australia?
     
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  6. Stevewoods

    Stevewoods Senior Member

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    Don't know if this Web site will work for you in the South Hemisphere, but it is the Toyota Motor Corp. site for owners to register their vehicles.

    It will at least tell you if any official recall work has been done on the vehicle and should tell you about any work done at any Toyota dealer.

    Again, that is in the USA. It may work for your country, or there may be another site that Toyota has for your region.

    Log into Your Toyota Owners Account | Toyota Owners
     
  7. Phildo

    Phildo Member

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    Ford stopped making the Falcon in September last year. It was a fairly large, 5 seat car that was made in sedan, station wagon and ute form. There was once a panel van version as well.

    The Ford Falcon was made in 6 cylinder and V8 versions. There was also a turbo version of the 6 cylinder motor, and that one was actually quicker than the V8s.

    For decades, almost all taxis in Australia were Falcons. In recent years there has been a move toward Toyota hybrids as they are cheaper on fuel.

    I used to drive my Falcon taxi but pulled the pin on that a year ago. Uber has wiped out the taxi game here, and it's all about poverty for taxi drivers now. My car was a station wagon, and I used to belt it around pretty hard. I even put Brembo brakes on it (repeated stops of a 2,000kg car results in heat fade on standard calipers).

    [​IMG]

    [​IMG]

    In the whole Holden (ie our version of General Motors) vs Ford thing I was always a Holden person, but as I developed mechanical skills and familiarity with the Falcon platform I bought a Ford Performance Vehicles (ie FPV) ute. That one has a turbo 6 and produces 270kW at the engine:

    [​IMG]

    It will soon be replaced with another one that was modified by a previous owner to produce 353kW (473hp) at the rear wheels:

    [​IMG]
     
    #7 Phildo, Mar 23, 2017
    Last edited: Mar 23, 2017
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  8. Phildo

    Phildo Member

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    I spent a bunch of time last night Google searching and reading through various different car forums. There were all sorts of opinions about whether or not to use anti-seize, and if so, what sort to use.

    There were numerous posts recommending to use copper anti-seize, and Loctite's official info on it recommends that particular one for use on spark plugs. I went with a majority vote and decided to use the copper stuff that I've already got (ie it was after midnight, so there wasn't an option to go shopping).

    Loctite's info: "A premium quality copper anti-seize and thread lubricant that may be used to prevent seizing, corrosion and galling where high temperature conditions exist. Temperature range: -30 F to 1800 F. Provides good electrical conductivity. Typical applications include spark plug threads installed in aluminum, exhaust manifold bolts, engine bolts, oxygen sensors, knock sensors, thermostat housing bolts, fuel filter fittings and battery cable connections."

    I actually removed the spark plugs from this car a week ago and put them back. They were quite difficult to initially loosen, which motivated me to put anti-seize on spark plugs for the first time in my life.
     
    #8 Phildo, Mar 23, 2017
    Last edited: Mar 23, 2017
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  9. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Thanks for those pics. It is so interesting to see. Those look like pretty nice cars. Nothing like the Ford Falcon's we know here which were made in the 60's and early 70's. Lol. :)
     
  10. edthefox5

    edthefox5 Senior Member

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    Thats a nice looking station wagon there.

    Interesting that Uber is so popular there too.
     
  11. Phildo

    Phildo Member

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    In other news, here’s what a blocked Prius catalytic converter looks like (from another car):

    [​IMG]

    [​IMG]
     
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  12. b100

    b100 Member

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    Dude change your brake fluid too!
     
  13. Phildo

    Phildo Member

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    That's on the list of things to learn and do.

    On previous cars (ie Ford Falcons), I used to flush the brake fluid every six months.

    I paid way too much for a Wurth brake fluid tester a few years ago. Useful, but I should have bought a cheaper generic one.

    [​IMG]

    I bought and used Speed Bleeders to replace the brake fluid nipples. They have a one-way valve inside them, which meant that I could flush the brake fluid on my own late at night.

    Speed Bleeders: Australian Ford Forums

    [​IMG]

    I'll be doing the same with the Toyotas... but I need to study it a bit and learn how to do it without stuffing up the ABS unit.

    Australian Ford Forums

    Speed Bleeders: Speed Bleeder Bleeding Brakes Bleeding Motorcycle Brakes Automotive Bleeder Screw Brake Bleeder

    [​IMG]
     
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  14. SFO

    SFO Senior Member

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    Looks like a good victim for trying out an acid bath.

    Also curious what color the liquid turns after bathing.

    Acid bath and P0420 | PriusChat
     
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  15. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC U0073 and U0121 are logged by the electric power steering ECU and indicates it does not have communications with the skid control ECU.

    Interesting that the spark plugs had previously been changed (although with the wrong type) when the car had fewer than 90K miles.

    I recommend that you consider cleaning the throttle body interior and throttle plate, and also the MAF sensor, using the appropriate cleaning sprays. The throttle body just needs some cleaner sprayed on a clean cloth, then use that to clean the plate and the interior as you rotate the plate 90 degrees by hand. Don't drown the throttle body in cleaner as some of the cleaner fluid may get into the throttle plate motor.

    If you still have a problem with the seized spark plugs on the other vehicle, would it help to squirt some penetrating oil into each spark plug well, and let the oil soak in overnight?

    Regarding the spark plug socket with the loose rubber, I recently bought a set of Craftsman spark plug sockets (sold as a set of 4) and used the 5/8" socket yesterday when changing the plugs on my daughter's 2007 with 102K miles. The rubber insert works as it should, with that socket. The benefit to having the rubber insert is that it helps to cushion and protect the porcelain spark plug tail.

    I use a 3/8" socket wrench on the spark plugs (vs. 1/4"). I think the improved leverage with a longer wrench helps to ease out the old plugs in a controlled manner.

    I also remove the wiper motor and the sheet metal tray that the wiper motor sits in, for access to the PCV valve. The PCV valve is hidden by the engine wiring harness running across the cylinder head cover. Your photos show that the PCV valve is clearly visible, and apparently that is an example of a different wiring harness arrangement for vehicles sold into a different geo market.

    Removing that tray also improves spark plug access as that you don't have to contend with the wrench bumping into the tray.
     
    #15 Patrick Wong, Apr 23, 2017
    Last edited: Apr 23, 2017
  16. blaisep

    blaisep Junior Member

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    Today I soaked my catalytic converter in the oxalic/citric acid solution for a few hours. I don't know how much it accomplished yet. I'll look at the liquid in the morning and let you know.
    Backstory:
    My wife's 2008 threw a P420 which I could no longer ignore. It's been going through a lot of oil (~1qt per 3500 miles), so after a lot of homework, my plan was:
    • Replace engine air filter, spark plugs (despite only 60K miles on them), and air/fuel sensor
    • Clean MAF (forgot to do the throttle body)
    • Inspect, clean O2 sensor
    • Acid soak the catalytic converter #1
    I failed to replace the air/fuel sensor because I couldn't find the right tool.
    The spark plugs were a mess!!
    [​IMG]
    I don't know what to make of all the oil seeping into plug #1. The coil shell had spots of oil up and down.
    Acid bath:
    1. Electric hotplate on garage floor
    2. 22 qt Stock pot with 2 inches of water
    3. Plastic cylindrical "tall kitchen" trash can (perfect fit)
    4. Next I hung the exhaust assembly from the ceiling a and lowered it into the narrow trash can so it just touched the bottom.
    5. I slowly poured most of the solution through the hole for the O2 sensor, hoping to push some carbon out the bottom.
    6. Time constrained me to a 5 hour soak and the water temp got only up to 110F or so.
    While the soak was happening, I bled quite a few bubbles from the brakes and adjusted the rear drum pads. The parking brake has less travel now. (but I have warning lights for brake ABS and VSC...)

    I love this forum and I wish I could contribute more often!
     

    Attached Files:

  17. valde3

    valde3 Senior Member

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    Oil leaking into spark plug tube is caused by bad valve cover gasket.

    How did you bleed the rear brakes? You do need Techstream (Mini-VCI is cheap) to bleed them. Prius brakes are not directly operated by brake pedal.
     
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  18. blaisep

    blaisep Junior Member

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    Good call. I'll look into replacing the VC gasket.

    I think I foobar'd the brakes because I tried following the "non-Techstream" method described in a toyota manual PDF and then realized it was for Gen 3 !!
    :cry:
    Now when I try to jumper pins 4 and 13, I don't see any codes and I can't clear the "brake, ABS VSC" idiot lights.
    Amazingly, I can't even get that right.

    I would love to get Techstream, I even have an win XP laptop I can dedicate to it.
    My confusion is that all the ads I see on Amazon an eBay are for cable only and the device driver.
    I have bad experiences with USB cables using cloned Prolific or fake FTDI chips so I would appreciate a specific recommendation for a known-good vendor.
    If anyone in the (Slicon Valley/Santa Cruz Mtns) area wants to do me a solid, feel free to contact me directly. (Actually, I'm a ham radio operator, so a contact from Finland would be really cool!)

    Thanks in advance,
    -Blaise
     
  19. valde3

    valde3 Senior Member

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  20. SFO

    SFO Senior Member

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    Number of miles on the car? (can't wait to see/hear more about the acid bathing experience)

    Those spark plugs have a heavy deposit, most likely from burning oil, but anything relating to the A/F mixture should also be tested/cleaned (how did that engine air filter look?).

    What weight oil are you using?

    Are there any codes being thrown?

    Pretty sure you can turn off the idiot lights by power cycling the vehicle 3-4 times (if the lights stay on there is a persistent issue that should be addressed by reading/scanning the logged codes) or they can be fully cleared by disconnecting the 12v battery for a period of time (best to gather existing logged codes before completely clearing a vehicle).

    Did have a chance to read these two entries on the Hobbit site (towards the bottom, titled: brake fluid) here : 100K maint - 1

    and here : Brake service
     
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