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How to Change the Spark Plugs in Your 2004-2008 Toyota Sienna

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George likes to do his own maintenance on his vans and trucks. Occasionally, he makes stuff out of wood.

It's Gotta Be Done

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Toyota recommends the replacement of spark plugs, typically when your vehicle reaches 120,000 miles. This routine maintenance can be very costly. The dealer I talked with proposed $900 for the job, which seemed unreasonable for a set of cheap spark plugs. Let's look through the work that is required, and you can make the decision yourself whether to do it yourself.

Since I have done this already myself, this article should serve as a helpful guide for those of you in the same predicament. There really isn't any need to disassemble a large part of what's under the hood. I try to show how to get the spark plugs replaced with the least amount of work required. I estimate it will take two to four hours, but you need a long reach and strong, nimble fingers.

What Do I Need?

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
  • 4- and 8-millimeter Allen wrenches
  • 10-, 12- and 14-millimeter sockets (the 10-mm will be used most often)
  • Rubber spark plug socket (5/8 inches)
  • 10-millimeter wrench
  • 12- and 14-millimeter ratchet wrenches (makes things easier...)
  • Small ratchet with extensions
  • Flexible ratchet
  • Gloves
  • Standard and needle-nose pliers

Optional

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
  • Paper towels
  • Flathead screwdriver
  • Duster
  • Electric tape
  • Hat (your hair will be brushing against the vehicle a lot)
  • Towel (to cover the parts that you will be lying on)

First Disconnect the Battery

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

While wearing gloves, use the 10-millimeter wrench to loosen the bolts on the battery. Carefully remove both sides and separate them from the battery, being extra careful not to touch both connections at the same time (otherwise you could get shocked). There should be a slight sizzling sound, which is okay.

Place a towel over the battery area, or otherwise, make sure the area is safe for working. There will be lots of time spent leaning over this area, so make sure it's set up in a way that is safe.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

First Set of Three Spark Plugs

The spark plugs are split into two sections, three in the front and three in the back. The front three plugs can be replaced in about 15 minutes, but be prepared to set aside an additional two to four hours for the rear three plugs.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Remove the Cover

Grab the smaller Allen wrench and unlock the three bolts on the front of the frame. Once you unlock them, it should be fairly quick. If you have trouble getting a bolt to unlock, use pliers on the Allen wrench.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Change the Spark Plug

First, remove the bolt on the side, unclip the wiring, then gently pull the long tube out of the hole.

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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

The Special Spark Plug Tool

There is a 5/8th-inch socket specifically designed for spark plugs. This socket has a rubber lining which allows gripping and gentle installation. Connect this to a ratchet with a long extension, along with the socket, and unscrew the spark plug from the hole. Once it is pulled out, place the new spark plug in the socket and gently screw the new one into its place.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Replace the Other Two Front Spark Plugs

Repeat these steps to replace the remaining two front spark plugs. On the three rear plugs, the method will be the same, but with less room. On the rear plugs, no detaching of the wire assembly should be necessary (as they made the cables long enough to pull the spark plug tube out without detaching the wiring).

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Remove the First of Three Items

To get to the rear spark plugs, you will have to detach three items. The first and simplest is the set of cables above the exhaust manifold, just above the new spark plugs. It's in the way and will need to be moved. Only three 10-millimeter bolts, a cable, and a few pipes need to be detached and moved. Disassemble so that this piece can be moved over the front spark plugs, out of the way, but there is no need to take anything out of the hood yet.

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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Start Removing the Exhaust Manifold

Just to continue in this section, remove the four bolts that require an 8-millimeter Allen wrench. No need for any extravagant tools here. Once the bolt is unlocked, it can be removed by hand. After removing the four bolts, remove the two 12-millimeter bolts on each side, and then remove the metal framing. Take this piece of framing out of the hood and set it down for reassembly later. Unfortunately, this is only the beginning of getting that exhaust manifold off.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step

Remove Item 2 of 3: The Air Filter Unit

Proceed by removing just the tubes and bolts so you can pull out the air filter unit. It's fairly simple. There are two small 10-millimeter bolts and several tubes to disconnect. Pulling the large tube off the exhaust manifold on the right should take a little force, but you can easily reassemble it later. Place this piece outside the hood, next to the engine cover and exhaust manifold bracket taken out earlier. This is the last piece that will be pulled out completely.

how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step
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how-to-change-the-spark-plugs-in-your-2004-2005-2006-2007-2008-toyota-sienna-step-by-step