How to change rear spark plugs
Replacing the back "bank" of spark plugs will require that you remove the Intake Manifold/plenum. Some have got to them without it, but a little more worth and swival/extensions.
I replaced my 2005 Sienna rear plugs without removing the Manifold by removing the Windshield Wiper Housing (5 Minute job). It gave you 6 inches of room to get your fingers in there. Trying to remove the left rear without removing the wiper housing is near impossible.
These are the steps: 1 - Remove the wiper bolt and wiper. Then Pop out the plastic cover. It is just held by plastic "V" inserts. 2 - Unscrew the bolts in the metal bottom and pop out the bottom. All easy 5 minute job. 3- You can easily see the Plugs and the bolts to remove. there are few things with sharp edges. Use tape or something to cover them if you don't want to get cuts. 4 - Rest is simple plug removal. I tried to remove the left rear plug previously for hours without removing the wiper cover and could not do it. It took me less than 10 minutes with the wiper cover off.
I changed sparkplugs on my 03 sieanna same motor.i got left rear plug on passenger side out by removing hose from pcv , and got the other two out with a lil patients.i didn't have to remove nothing to get to plugs just that hose from pcv.i used a 1/4 ratchet and abot a 3inch extention,and a 3/8 to 1/4 adapter.that way way I could use a 3/8 drive sparkplug socket.i recommend getting a magnetic sparkplug socket fom autozone.that way you wont have to worry about that rubber brooment coming out.also use ngk or denso long life laser iridum plugs.my van has went from 308 miles per tank full to 370 per tank full in city.havent drove it on hwy yet.just remove plastic engine cover,scope it out and take your time.it took me 2hrs 30mins.
the 2003 is a different motor johnboy84. It is the 3.0 litre v6. Much easier to work on. 2004 they switched to the 3.3.
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