When you replace plugs, do you need to replace the gasket too?
Please share how-to video link that I can follow
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Have a 2016 SE and 2006 CE Siennas. For what it’s worth, had the original spark plugs replaced at the dealer on the 2006 at 200kmi, they looked brand new…no oil or wear.

in terms of DIY, the tears are pretty tough to get to.

 

First of all, the manual for my 2014 recommends 120,000 interval. As of 2017 the Sienna Gen 3 was given a different V6 so they may have reduced the interval. Check your manual for the right interval if you've not already done so. In the future you should state your year, trim, 4 cyl. or V6 if applicable to the year, and also FWD vs. AWD if applicable to the year. That's best done in your profile so it shows up below your screen name.

Further, the 2014 manual has a footnote saying spark plug maintenance is "required under the terms of the Emissions Control Warranty." That's strange since no emission system component is warrantied past 80 months / 80,000 miles. See what your manual says on this matter.

The youtube videos told you what you need to know about difficulty--a lot of disassembly / reassembly to get to the rear spark plugs. A dealer is probably going to charge 3-4 hours labor. Expensive job, somewhat cheaper with an independent buy I'd look for one with experience doing this job. I would not want to be somebody's educational experience.

For the earlier Gen 3 V6 engine such as mine, I've seen several reports of folks going well past 120,000 and finding the plugs were still in good shape. Some fewer reports have said they found the plugs were seized. It's your call. I'm at 119,000 miles and I'll be paying the dealer probably $200 more than an indy at my next oil change because 1) I've yet to find an indy I'd trust with the job, 2) I have money and 3) the dealer I go to does good work and does not try to foist unnecessary stuff.

 

I added the year and engine …it’s 2015 and V6

 

Not a video, but I posted a picture thread here when I did them at 120,000 miles on my 2014 (same engine as you): 2GR-FE Spark Plugs - A How-To Picture Guide (2014 LE)

Hard? Depends how much experience you have working on cars. It’s definitely time consuming.

The interval is 120k, not 100k, so you’ve got another 20k to go.

 

I replaced mine at 100k and again at 200k (2016 Limited)

Both times went smoothly with no need to replace the donut seals or valve cover gaskets

Plugs looked new each time and since I rack up miles pretty quick with a 200+ mile daily commute (currently at 276,xxx), I plan on pushing my next interval to 400k

 

When you do replace, might as well replace the 3 back coils and save them if your front 3 go bad. Also clean the TBI and manifold, replace gaskets as necessary. There’s also some hard to reach hoses to consider back there if desired.

 

I just did this a couple months ago on my 2014 XLE at ~124k miles. It's not a hard job but you need work methodically. I used blue painters tape on both ends of everything I disconnected and numbered them so I knew where everything went back. I watched these videos a several times before I started:

2011 - 2016 Toyota Sienna DIY Replace Spark Plugs, Coils, Intake Manifold Gasket V6 3.5L (2GR-FE)

How to change spark plugs on V6 Toyota and Lexus 2GR-FE 3.5L engine

Should you clean your Throttle Body and How to clean it on Toyotas

Like copydoc said, replace the 3 rear coils and clean the throttle body while you're in there.

Gaskets are inexpensive so I replaced the throttle body gasket and 3 intake manifold/surge tank gaskets. I replaced the PCV valve too.

Take care when disconnecting the coils because the connectors break just by looking at them. I started on the front plugs and I'm glad I did because I snapped the tab on the first connector I touched. It was easy to de-pin and replace as shown in L35's video.

The hardest part of reassembly was the rear surge tank bracket. The Car Care Nut video discusses this in detail. You have to do it blind so take your time and you'll eventually get the bolts in.

I recommend you use OEM coils and spark plugs. Yes they cost more but you're saving a bunch of money doing this yourself and you don't want to go back in there next year.

Good luck!

 

Here’s the laundry list I asked the shop to quote. Fwiw, it’s been a week and no response yet. Typical with these dealership bozos, it’s not rocket science. Tbh it’s nothing I could do and small shops around here often cringe when I say it’s for a Sienna 6cyl. So…


+Replace Spark Plugs x6, Iridium (keep old parts for owner)

+Replace Rear Coils x3 only,
(keep old parts for owner)

+Clean Air Intake Manifold
+Replace Air Intake Manifold Gaskets (Top Only)

+Throttle Body-Plate Cleaning/Service
+Replace Throttle Body Gasket

+Replace Hose, Ventilation, No. 2 (OEM Part #122620P170)
+Replace Hose Assy, Ventilation (OEM Part #122600P040)

+Fuel Injection System Cleaning/Service

good luck!

 

This one isn't bad and he calls out the torque values at reassembly. This is the only way to do it - no shortcuts are available.

If you have a decent set of tools and some experience turning them, the job is super easy - just takes time to take it all apart (3/8 drive ratchet with metric sockets, wrenches, pliers, torque wrench that'll do 5-30 ft/lbs (usually a 3/8 drive torque wrench is in this range for the plugs and all fasteners in this job).

Some of the coil on plug (COP) wiring connector clips WILL break. They're brittle. Decide before if you want to zip tie them or get some replacements beforehand. The video above covers this.

If you have compressed air, use it to blow out the dust just before you're ready to remove the upper intake plenum. Also good to have a shop vac to clean up after you remove the plenum. Put some clean shop towels in the intake ports. Murphy is present and dropping a bolt or nut in the hole will cause angst and wasted time fishing it out.

Also, it's not a bad idea to replace the back three COP while it's apart. Might as well for insurance. The front three can wait if you don't want to do them all - easy to get to later if needed. You can go genuine Toyota ($90/each) but I've had good luck with Delphi, NGK, Hitachi. Don't buy super cheap aftermarket.

You'll need a throttle body to manifold gasket and intake manifold to engine gasket.

It's good to have anti-seize paste (just a little for the plug threads; don't get ANY on the insulator or electrode) and silicone di-electric grease for the COP boots where they connect to the spark plug tops.

I like Rockauto.com for parts.

 

While the video from L35 in Colorado is the most comprehensive and very detailed where you can't go wrong for a DIY, there are some shortcuts you can take if you are a seasoned DIY'r. One trick is to remove the intake manifold without removing the cowl/ tray etc. See this vid around the 2:35 mark. Apparently, the manifold can be slid towards the driver side and removed.
2011 spark plug diy without removing the cowl

A couple of folks have also changed the rear plugs without removing the manifold, just accessing the rear coils by touch & feel and replacing the plugs. Yes, space is very tight and getting it plugs to Torque or not is also debatable but at the end of the day, it's your car, your time and your dime. Plsn on how you want to do it.
Also, the consensus seems to be that though the recommended change interval is 120K, plugs have been fine when replaced at this interval and it's mostly ok to take it higher. How high is again a personal choice.

 

Yes, It can be done. I have 2006 RAV4 and 2013 Sienna both with same engine. Purchased all the gaskets to do the big job but the middle rear coil pack went bad on the RAV4 before I could get to it. Needed the car so I did it blind. Changed the plug while I was in there. Took about 15 min with the right tools. The right tools being a good magnetic swivel spark plug extension GEARWRENCH 3/8" Drive 6 Pt. 5/8" x 6" Magnetic Swivel Spark Plug Socket - 80546 - Socket Set With Spark Plug Socket - Amazon.com and a compact fine tooth flex head ratchet. I did not have time to do the rest but while I had the tools out I checked and I had access to all 3 back plugs on both cars. There is a bracket on the passenger side that you need to move and the harness also needs to be pushed out of the way. Do yourself a favor and purchase a set of replacement coil pack connectors as they tend to break and crumble. Amazon.com: 90980-11885 Ignition Coil Connector Plug Harness Replacement for Toyota Lexus 4-Way Female (Pack of 6) : Automotive
Don't cut and splice. You can just pull the pins out of your old connector and slip them into the new connector. I used a precision screwdriver to remove them from the new plugs and just squeezed the old ones until they crumbled to remove the wires.
Install new OEM or Denso in the back. You can save money on the front ones if you want to chance it as they are easy to replace but the back ones are hard to do on the side of the road.

 

Great video but it makes me cry watching it

 

I had it done at the dealership~$800. Everything that is suggested you should do it because you are not going back in there again for years to repeat this job. a lot of stuff has to come off. Decide whether you want to replace coils, I think I did. definitely replace gaskets, and clean throttle body, DON'T cheap out and get the crappiest parts you can find....our 2015 sienna has been virtually trouble free because it came that way from Toyota. You could probably do it yourself but what a pain....there is a lot of stuff to keep track of and if you don't have all the tools, you are fkt. Anyway, I had it done!

 

You could probably do it yourself but what a pain....there is a lot of stuff to keep track of and if you don't have all the tools, you are fkt. Anyway, I had it done!

 

Our 12' XLE will hit 125K in a month or so. Initially, I was set to do the plugs at that mileage but then the Van runs just fine, no issues (knock-on wood), so now I am punting it. Will revisit after another 12-15K miles.

 

I thought about punting but I forget what stuff I found about what happens if you run on fumes until touchdown... That's an even older car...probably nothing will become of putting it off.....

 

I had it done at the dealership~$800. Everything that is suggested you should do it because you are not going back in there again for years to repeat this job. a lot of stuff has to come off. Decide whether you want to replace coils, I think I did. definitely replace gaskets, and clean throttle body, DON'T cheap out and get the crappiest parts you can find....our 2015 sienna has been virtually trouble free because it came that way from Toyota. You could probably do it yourself but what a pain....there is a lot of stuff to keep track of and if you don't have all the tools, you are fkt. Anyway, I had it done!

This is every single tool I used to change the plugs on my 2014 Sienna:

Full details on parts & tools required, and tons of pictures and text walking you through it on my thread here:

2GR-FE Spark Plugs - A How-To Picture Guide (2014 LE)

Well, it's time. Following up on my last post on a 2GR-FE water pump change, I now have successfully completed my 120,000 mile spark plug change on my 2014 LE. This may or may not be applicable to 2nd gen Siennas using the 2GR-FE engine. The spark plugs themselves should be, but the process of...

www.siennachat.com

It’s certainly much less of a pain than doing the water pump was!

Whichever way the OP goes, 100% agree don’t get the cheapest parts, and change at least the three rear coils. The front coils can be changed in two minutes on the side of the road with no tools if needed, but not the rear ones…

 

I've finally gathered all my parts, the hoses finally arrived this week. Will be doing mine this coming week. 2013 136k.
I liked this video the best, without removing a bunch of extra items that I saw in another video.

 

It's a placebo effect, but at least you know they're done.