See photos below and on subsequent pages.
2003 V6 AWD 307k miles.
You can do this. The dealer wants $480 for this service, I have done it twice now. The first time was brutal but the second time I must have learned something 'cause it went a lot better. Takes about three hours, start to finish with tools put away. Proper tools and sequence are important. My cost was $35 for plugs purchased on line. A savings of $445.
-3/8 drive ratchet: Pittsburgh (Harbor Freight) w/extender handle. Model 62312
-3/8 drive extension set: Channel Lock Wobble Extension Set 3, 6, and 10 inch. Part No. 350961 (I bought these for this job but had everything else. Nice set to have.)
-Extra extension: standard 3/8 drive 3-inch, Craftsman.
-3/8 drive universal joint, standard, Craftsman
-Spark plug socket: standard (no-name) 3/8 drive by 5/8 inch. Note: I have several of these but the one that works best has a rubber boot inside to grab the plug. You want it to gently hold the plug from slipping out yet loose enough to pull off the plug without separating from the extensions.
-¼ drive ratchet: Pittsburgh Model 62331. Has a longish handle.
-¼ drive extension: Three-inch (Tekton, I think.)
-¼ drive by 10mm and 12mm socket. (standard, Craftsman)
Spark plug tools: Coin type feeler gauge. These type work well to rough-check and adjust the gap. Then I use a flat feeler gauge for precision gap check. Only one of the six plugs needed adjustment (0.044 inch).
-Two 12mm open-end wrenches
-One 10mm gear wrench
-10 inch standard vice grips
-12 or 14 inch extra-long flat screwdriver
-5mm Allen wrench
-paint can opener key
-Good pen light or tactical light
-Magnetic mechanic's pick-up tool (optional)
-short step ladder (optional)
-Spark plugs, six, Denso SK 20R11 Iridium #3297
-Electricians tape, 3M Super 33+ (Tape socket extensions together and to armor your right forearm with wraps of tape. You'll see why later.)
-Permatex aluminum-based anti-seize, #80078 (Light coating on plug threads.)
-Permatex dielectric grease, #22058 (optional, small dab on tip of plug connectors)
Remove engine cover. Under the Toyota logo is a friction fit clip. Once the three Allen head nuts in the front have been loosened the cover pulls up and off. 5mm Allen wrench.
The front plugs are easy-peasy. I'm not going to comment on those except to say that there is no need to disconnect the electrical connectors. There is enough slack built into the wiring loom to remove the coil packs without removing the connectors. Also, the seal ring on the underside of the coil pack can fall off as you pull the pack. Keep track of these. It's easy to re-install a coil and forget to include the ring.
On to the dreaded rear plugs.....each rear plug has a different sequence.
- Loosen two 12mm jam nuts, slide cruise control cable from bracket on the throttle body. Two 12mm open-end wrenches.
- Undo end of cruise control cable from throttle body and flex out of the way.
- Remove cruise control cable mounting bracket. ¼ inch drive 12mm socket on ratchet with 3-inch extension.
- Working from the front of the car, access the coil pack from under the throttle body. This is why you removed the cruise control cable and bracket and adorned your forearm with tape. The underside of the throttle body has rough edges, careful. Using a light you can see the coil retaining bolt clearly below the throttle body. A gear wrench easily accesses the bolt. Unbolt coil and slide up then turn sideways and flex it out of the way. Do not disconnect electrical connector, just let the coil hang there. 10mm gear wrench.
- Slide socket with extensions down onto plug between firewall and cylinder head. Unscrew plug and withdraw. 5/8 spark plug socket, std 3-inch ext., wobble 3-inch ext., universal joint, wobble 6-inch ext., 3/8 drive ratchet. Total 17-inch reach.
- Replace plug. Move on to middle plug. Leave coil pack hanging for now.
- There is a random hidden ground wire above the middle coil pack that is in the way. By feel alone unbolt this wire from cylinder head, flex out of the way. You cannot withdraw the coil pack without unbolting said wire. 10mm gear wrench.
- Access the middle coil pack from under the throttle body. You can just see the coil bolt head and can feel it with your finger tips. The gear wrench can easily get on it. You need to shove your forearm way under the throttle body. Unbolt coil and slide up and sideways, flex out of the way. Do not disconnect electrical connector. Very-very tight clearance. The boot on the lower end of the coil tube will flex a bit to gain clearance as you turn it sideways. This is the hardest coil to pull but it can be done. 10mm gear wrench.
- Slide socket with extensions down onto plug between firewall and cylinder head. Unscrew plug and withdraw. (Same socket rig as driver side.)
- Replace plug.
- Re-install coil pack.
- Re-install driver side coil pack. Move on to passenger side.
Lastly, re-install (in order):
- Working from the fender side. Remove ell-shaped hose from PCV valve. Do not remove PCV valve itself. Once the hose is off the PCV, twist and pull the hose towards the fender to remove it fully. Vice grips for spring clamp ears. Long screwdriver to pry with.
- You need to disconnect the electrical connector from the coil pack (only this one). Tap the connector to loosen accumulated dirt and grit. Use paint can opener to press the connector catch and the tip of the screwdriver to pry the connector off. This is a hard connector to remove. (Tip: practice first on one of the front coil connectors.) Paint can opener and long screwdriver.
- Remove coil pack bolt. Pull coil pack up and towards the fender to clear cylinder head. 10mm socket on ¼ drive ratchet or 10mm gear wrench.
- Slide socket with extensions down onto plug between firewall and cylinder head. You can easily see the plug hole from the fender side. Unscrew plug and withdraw toward fender. (Same rig as driver side only substitute the top most 6-inch extension with 10-inch extension. Total 21-inch reach.)
- Replace plug.
- Re-install coil and re-connect electrical connector. You are almost done.
- ell-shaped PCV hose. Lube ends with a little light grease, slips on easy then.
- Ground cable to back of cylinder head. You cannot see the bolt hole. This will need to be done with finger tips of both hands. Go easy and deliberately. It took me about 10 minutes to get this sucker back in. It's okay to remove your hat and rest your forehead on the firewall. You'll see what I mean. Magnetic pick-up tool, (probably.)
- Cruise control bracket and cable. Note locator pin position on throttle body for alignment of bracket.
- Engine cover. Done! WoHoo!
A few tips:
-Find an assistant with small hands. Especially for pulling the electrical connector off the passenger side coil pack and removing the bolt from that coil pack.
-To install plugs, push the plug into the socket rig then thread the rig down the hole in the cylinder head. The wobble extensions help alot to “bend” the tool down into the plug well. You may need to disconnect the top-most (6-inch) extension then reconnect it once the plug is down the hole.
-Tighten plugs by hand until snug then another ½ turn 'til you can feel the seal washer has crushed.
-Some say anti-seize is not needed for spark plug threads, but I used it the last time (147k miles ago) and the plugs came out smoothly with no corrosion on the threads.
-Pulling the entire intake manifold and throttle body is the other method used to get at the rear plugs. I have not done it but I've seen pictures on the web and it does not look like fun. With the right tools and sequence this procedure is far easier and faster. Good Luck!
Photos, left to right: Sockets-extensions taped together. Go over the top! Socket holds plug nicely. PCV hose. Rig positioned down plug well-drivers side.