Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Toyota Sienna Care & Maintenance



  • Thanks for all the help here. I should have done this before deciding to do the plugs myself. My s-10 pickup was so difficult I just returned the plugs.
  • jeproxjeprox Posts: 466
    yes we are talking about two different things. the plastice piece you referred to is just a cover - just like what pjksr mentioned. the 3 plugs for the rear bank are not under that cover! i wish they were though! :)

    yes the piece i'm talking about is the black plastic piece (cowl) that runs along one side to the other. (the one with the sticker). yes, that whole piece needs to come off! i seem to recall that the wipers needs to come off before that piece can be removed! so you can just imagine how much work is involved to replace the 3 plugs in the back! if you don't remove the cowl, you won't have enough room to get in the back and under the manifold. the rear bank is very close to the firewall. from what i remember, you need not remove the manifold to get access to the plugs.

    while you are back there working on the plugs, i recommend you to change your pcv valve as well since you're already back there! :)

    PJKSR: i painted the plastic cover myself along with the air filter box, battery terminal cover and a few other things. i used ford blue high heat paint. don't know if you can see on the pictures but i also installed an invisible bug screen behind the grill. :) works great in protecting my radiator.
  • jeproxjeprox Posts: 466
    my suggestion to you is start early on a saturday morning if you want to replace the last 3 plugs. i can guarantee you that you need at least 1hr for the job, if not more.
  • pjksrpjksr Posts: 111
    To all who are reading, you may know that you can't buy a Chilton's manual for your Sienna.

    However, I have found in my local public library, a "reference" Chilton's manual that has a section on the Sienna. Look for a large manual that covers Trucks and Vans; these manuals come out yearly and cover many auto-shop-type procedures.
  • jeproxjeprox Posts: 466
    yes there are no chilton manual for sale.
    the one i have is the oem repair manual for 1999 model.

    gsafarz: i just looked at my manual and yes you have to remove ventilator louver and then the cowl. after you remove the wipers of course! :)
    once everything is off - you will get good access to the plugs. u can try gaining access from the bottom, you may be able to get away with it.

  • 1846618466 Posts: 46
    Just replaced ours about a month ago from under the hood. Took some doing but I only removed the plastic engine cover (two allen bolts) and managed to reach behind the intake with a 3/8 inch rachet and extension and a couple of bruised knuckels. Do this when you have nothing to do for a few hours. You can reach the sparkplugs by reaching under the part of the intake that is connected to the throttle body. You won't see what you are doing but you can trace the wires. Remove them one at a time and then remove each plug. I did all 3 back plugs one at a time by reaching under the back of the intake by the throttle body (enough room to swing a rachet back there ). As for the sparkplugs Autozone has the same ND plugs that were in our van (double ground electrode platinum) for about $6.00 each. On a 2000 you don't need to remove any of the engine compartment cowl. I don't know about the later ones (2001+)with the VVT if there is enough room. Good Luck!
  • pjksrpjksr Posts: 111
    18466, What was the condition of your plugs?

    Does your 2000 require "Iridium" plugs like the 2002?
  • 1846618466 Posts: 46
    At about 62000 miles the plugs looked a little worn. The gap on the plugs seemed to be almost twice that of the new ones. There was no noticible change in performance or mileage between the old and new plugs (Van has always ran good). The insulators on the old plugs were a light brown. The plugs for the 2000 model are platinum with dual ground electrodes.
  • pjksrpjksr Posts: 111

    Well, I'm looking forward to changing my plugs in about 2 years. Like you said, it sounds like a job for a Saturday morning.

    BTW, 18466, and anyone else, have you checked or had checked your valve clearances? I'm wondering how common it is for them to be out of spec...
  • mrk4mrk4 Posts: 9
    Going in for another oil suggets tranny fluid change as well. Could not find this service mentioned in manual. Does anyone know when this service item should be changed? Sounds like dealer will be doing my plugs after reading this board. I believe 60k is recommended time frame?

  • pjksrpjksr Posts: 111
    mrk4: There's no interval for the change, unless you operate under "special conditions;" then, it's each 30,000 miles.

    Now, how much will they charge you, and will they just do a "drain and refill," or will they do a flush? IMO, a drain and refill is good enough; you can do it yourself for less than $10, using quality fluid (like Havoline) and a little effort; there's a discussion about this earlier. At any rate, changing ATF is cheap insurance for keeping that silky smooth tranny workin' right. And double-check your fluid level after anyone touches it.

    There are other obvious things to change too, as I'm sure you're aware, including the air filter and pcv valve...
  • 1846618466 Posts: 46
    I never checked the valve clearances. I was told by a mechanic at the Toyota dealer that they don't really need to be adjusted if they are not noisy. As far as changing the tranny fluid I open the drain plug (10mm Allen) and drain and add new fluid every 15000 miles. It's probably overkill but it only takes about 2 1/2 quarts to do this (Dextron III). You can't dump the fluid in the converter so I do this just to keep it fresh. I don't like tranny flushes because if there is some dirt you dont want to lodge it into somewhere where it could cause problems.
  • pjksrpjksr Posts: 111
    18, Thanks for the valve clearance info...

    You may want to check early in this thread, because there's a procedure for draining the ATF, kindly posted by an owner who called Toyota on it. Upshot is that if you drain the differential and tranny drain, you'll get out much more than 2 1/2 qts; more like 5 1/5 or more. At any rate, even 2.5 @ 15k would freshen the fluid pretty well.
  • 1846618466 Posts: 46
    I researched it and found that if you drain the differential with the tranny you can drain only 3.7 quarts of fluid. Which is what some dealers normally drain when they service the transmission. More than the 2.5 quarts I get when draining the tranny only. Toyota service manual describes servicing the tranny only. You are right this gives it a fresh recharge when I service it every 15k. It takes about 5 minutes to do on the Sienna.
  • I have a question on removing these plugs. This is a coil on plug type designed engine. Don't you have to remove each of the coils to gain access to the plug?
  • 1846618466 Posts: 46
    There are only three coils. They are above the front spark plugs. These coils have to to be removed to remove the front plugs. Each coil supplies spark to two cylinders one front and one rear. If you look closely at each coil you will also see a spark plug wire going to each of the rear plugs. These coils fire twice for each cycle of the engine, once for the power stroke and then again on the exhaust stroke Because of this only three coils are needed for a six cylinder engine. This is why the type of plug is so important. They fire twice as often and wear twice as fast. This is the major reason that Toyota only recommends the dual ground electrode platinum or iridium plugs for the Sienna.
  • Guys, I am a do it your selfer. I no longer want to pay to have the dealership change the transmission fluid. I also have never performed this task. Can you give me just some basic things to look for and follow. ie drain bolt, fluid refill point, and or any thing else that would be really handy. I know i wont have a problem with this, and as everyone knows there are no generic service manuals for siennas. I know just after a conversation or two with you guys i will know all i need to know.
  • lsaclsac Posts: 22
    Remove drain plug and drain the ATF.
    Reinstall the drain plug securely(NO TORQUE MENTIONED)
    With engine OFF add new ATF thru the filler pipe. (3.7 qts)
    Start engine and shift the shift leveler into all positions from P to L and back to P.
    With engine idling, check the ATF. Add ATF up to the COOL level on the dipstick.
    Check the fluid level at normal operating temperature, 158-176F and add as necessary.

  • You can change the fluid by way of just draining the fluid. Or you can drop the pan and clean the filter/screen as well as the pan and magnets I would suggest you drop the pan every 30,000 miles and then drain in 15,000 miles. This is not specified anywhere by Toyota - they just say change it at 15 if you are a severe user, etc. In my mind it is cheap insurance to follow this schedule. You won't end up posting one of these "my Sienna only has 65,000 miles on it and the transmission failed... the manual never said anything about changing the fluid....

    I got a Mitchell repair manual ( on CD. So, there is a "generic service manual for Siennas...." My only note is that for my 1999 LE, there is not much info on the CD - I refer back to the 98 model year.

    The drain bold is on the pan. You will also see a differential drain plug right near the pan, but I cannot remember its size. Mine took the 3.7 quarts of fluid as specified in the owner's manual to refill.

    In regards to rear plug changing, you can get a tool from Snap-on that will get to the back plugs without removing the Cowl. I would not invest the $50 for the socket/u-joint combo since you only have to change these plugs every 60,000 miles. The Cowl and plenum takes about 15 minutes to remove. (The guy who said 10 seconds has obviously never removed each piece... and I have an air wrench to remove the screws quickly...)

    Hope this is of help.
  • 1. when i refill with new atf fluid, does this get added thru the aft dip stick shaft?

    2. obviously, just draining thru the drain plug sounds easy. it has been about 25k miles since the last atf fluid change(it was at the dealer ship where they flushed thru the torque converter). so with the info you guys gave me i am thinking about dropping the pan since its been 25k miles. Now, when i drop the pan, do i need to replace the gasket??

    3. when i clean the pan, what do you use to clean the pan? parts cleaner? brake cleaner? non residue spray?

    4. Is there any filter that i should change?

    5. is there a torque specification for the pan bolts?
    I will check out the web site on the sienna manual!
    Thank you for your input, it is a great help!!!
Sign In or Register to comment.