First off, I am no expert mechanic. I have some basic understanding of vehicles and use the internet to find out more. Since day 1 of buying my vehicle new, I've done all of my own maintenance thanks the awesome users of this forum. THANK YOU GUYS! Also, I should mention that this is my first attempt at changing spark plugs, so hopefully it can give others confidence to do the same and save them some money too. If any real mechanic would like to chime in to let me know I did something wrong or should have stated 'this or that', feel free.
For any maintenance posts, I like to be as thorough as possible to cover things that a newbie like myself might have questions on. I didn't see a completely thorough post on how to get this done although some very good ones! So I wanted to post up something detailed. I hope it helps someone else.
First off, thanks again to all the other posters in the following threads. After reading all of these threads, I had the confidence to tackle this task myself.
Good short writeup on changing spark plugs on 2008 4.0L 4Runner
http://www.toyota-4runner.org/4th-gen-t4rs/85813-2008-4runner-4-0l-spark-plug-diy.html
Interesting debate er...conversation on Spark Plugs for 3rd gen 4Runners
http://www.toyota-4runner.org/3rd-gen-t4rs/13126-spark-plugs.html
Great tips from TINMAN080 on this forum, some of which I also mention below:
Hard to change spark plugs?
According to http://www.sparkplugs.com, the type of spark plugs that are compatible with my 2008 V6 4Runner are:
Tech Bulletin from NGK: Anti-Seize Compounds on Spark Plug Threads
http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf
After much reading, I decided to go with the NGK Laser Iridium Spark Plugs. I bought 6 of them at a local O'reilly Auto Parts store. They cost about $10/each.
NGK Laser Iridium - Part #4904
NGK Laser Iridium 4904 - Spark Plug | O'Reilly Auto Parts
Tools:
Small 1/4" drive ratchet with 10mm socket
Large 1/2" drive ratchet with 8" extender, and 5/8" Spark Plug Socket
10" clear vinyl tubing (1/2" OD and 3/8" ID)
Small (but long) flathead screwdriver
Soft towel for protecting paint on fenders while working in engine bay
Soft towel for laying new spark plugs on to protect against ground scrapes.
Towel for cleaning grime off ignition coils
Six new NGK Laser Iridium Spark Plugs
Some notes:
I did not use anti-seize (see tech bulletin above).
Gap specification in my 4Runner manual says 0.043.
Gap specification listed on NGK's website for the Laser Iridium is 0.044.
Clean off ALL dirt and grime around the area BEFORE doing any work.
Be careful not to drop any bolts, plugs, hose clips or tools down the engine compartment.
Be careful dirt and grime doesn't fall into engine block when plugs are removed.
Do not drop the spark plugs on a hard surface as it will damage them.
Drivers side plugs are more of a pain to access than the passenger side plugs.
My ride has 67,000 miles and most of them have been highway.
I have a 2008 Sport Edition V6.
4th gen were first 4Runners with aluminum engine blocks (I think?).
Steps I took to replace each side of spark plugs: (passenger side first)
1. Pop the engine hood. At this point I always lay a towel over the fender to help protect the paint. It also helps to keep your shirt clean as you lean over to access certain areas of the engine compartment. I chose to remove the plastic cover on the engine, although I don't think this is required to reach the plugs. There are two 10mm nuts to remove the cover.
2. Reposition the engine air filter for access. Pop the two clips on the engine air filter and carefully push the engine air filter out of the way. You can now see the ignition coils.
3. Unclip the electrical wires. Use a small flathead screwdriver and carefully unclip the electrical wires that are plugging into the top of the ignition coils. My clips were extreme tight and it took some careful prying with the screwdriver. I had to squeeze the little release mechanism really hard and then I placed the screwdriver in the small gap between the male and female parts of the plug and then gently rotated the screwdriver (like I was unscrewing a screw) to force the plug out. If you can't mentally keep track of which wires go on which plug, you should label them accordingly, immediately after removing each one. Toyota makes it relatively easy though as the placement and length of the wires really dictate exactly where they should go.
Middle electrical wire I bent back to get it out of the way.
4. Remove the bolts on the ignition coils. Grab your small socket wrench and remove the three 10mm bolts holding in the ignition coils. There is one bolt per coil. I used one with a short handle because it works well in tight areas. Although the bolts are the same size, I prefer to keep them ordered and place them back into the same hole from which they came. So be careful to label them if you want to replace them in the same hole.
5. Remove ignition coils. This is easy. Just pull up on each one to remove out of the spark plug wells. It is important to note here that BEFORE you remove these, all dirt and grime should be thoroughly removed from the area. You do not want dirt and grime dropping into your engine block as you pull out the spark plugs. There is also a rubber washer that might be a little stuck to the engine. Be sure to gently remove these with the ignition coils. I was also careful to keep these in order as well and replaced them in the same well from which they came. It's probably not necessary but I prefer to do this anyway.
6. Now remove the spark plugs. You can see the park plugs down in the wells. Grab your large socket wrench with extender and carefully loosen each plug. Turn counter-clockwise. (Please note, my 5/8" deep well spark plug socket did not have the rubber insert that sometimes comes with these special sockets). I loosened each spark plug about 3/4 of the way out. Then I took a 10" piece of clear vinyl tubing and pushed it gently down the well and onto the spark plug until it snuggled onto the top of the plug. Then I simply rotated the hose a few times to remove each spark plug. You'll notice that my tubing is curved. That's the way it came off the roll at the local hardware store. To fix this, I took my long but narrow screwdriver and slid it into the tube. This helped keep it straight while rotating the tube to get the spark plug all the way out. I found out on the first plug that if you use the ratchet to unscrew the plug all the way out, then it falls (tilts) against the edge of the well and it's more difficult to get the tubing to slide onto the top of the plug.
7. Now install the new spark plugs. I used to the vinyl tube trick to get each plug started when installing the new plugs and screwed them in with a few turns of the tube before switching to the socket wrench to tighten all the way down. I tightened them pretty good but I was very gentle and careful not to over-tighten.
8. Reinstall the coils carefully. Don't forget the rubber rings.
9. Reinstall the 10mm bolts that hold the ignition coils in place.
10. Reattach the wire plugs to the ignition coils.
11. Reattach the engine air filter.
****
Now for some notes on replacing the drivers side spark plugs.
First, the drivers side was quite a bit more difficult to access. I started out by cleaning the area. Quite the pain. Luckily my hands aren't that big so I could get my towel in there and clean things up ton remove the larger dirt particles. This side had more grime on it than my passenger side for some reason.
Second, I removed only the vacuum hose and some electrical plug, as indicated on the photo below. At first I thought I was going to have to remove much more, but you can get it done by only removing the hose labeled below.
Third, the removing the middle plug on this side was an absolute *****. There is barely enough wiggle room and you have to use one hand to bend hoses out of the way while holding on to the damn ratchet extension while trying to make little tiny 5 degree rotations back and forth. It took me way more time to get this one out than all the rest.
After you're finished with the plugs on the driver side, don't forget to plug in the small electrical connector and the vacuum hose. Fire that puppy up and if it starts, you're done.
****
Extra notes.
For my OEM plugs I had three Denso plugs on the passenger side, and three NGK plugs on the driver side.
For any maintenance posts, I like to be as thorough as possible to cover things that a newbie like myself might have questions on. I didn't see a completely thorough post on how to get this done although some very good ones! So I wanted to post up something detailed. I hope it helps someone else.
First off, thanks again to all the other posters in the following threads. After reading all of these threads, I had the confidence to tackle this task myself.
Good short writeup on changing spark plugs on 2008 4.0L 4Runner
http://www.toyota-4runner.org/4th-gen-t4rs/85813-2008-4runner-4-0l-spark-plug-diy.html
Interesting debate er...conversation on Spark Plugs for 3rd gen 4Runners
http://www.toyota-4runner.org/3rd-gen-t4rs/13126-spark-plugs.html
Great tips from TINMAN080 on this forum, some of which I also mention below:
Hard to change spark plugs?
According to http://www.sparkplugs.com, the type of spark plugs that are compatible with my 2008 V6 4Runner are:
Tech Bulletin from NGK: Anti-Seize Compounds on Spark Plug Threads
http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf
After much reading, I decided to go with the NGK Laser Iridium Spark Plugs. I bought 6 of them at a local O'reilly Auto Parts store. They cost about $10/each.
NGK Laser Iridium - Part #4904
NGK Laser Iridium 4904 - Spark Plug | O'Reilly Auto Parts
Tools:
Small 1/4" drive ratchet with 10mm socket
Large 1/2" drive ratchet with 8" extender, and 5/8" Spark Plug Socket
10" clear vinyl tubing (1/2" OD and 3/8" ID)
Small (but long) flathead screwdriver
Soft towel for protecting paint on fenders while working in engine bay
Soft towel for laying new spark plugs on to protect against ground scrapes.
Towel for cleaning grime off ignition coils
Six new NGK Laser Iridium Spark Plugs
Some notes:
I did not use anti-seize (see tech bulletin above).
Gap specification in my 4Runner manual says 0.043.
Gap specification listed on NGK's website for the Laser Iridium is 0.044.
Clean off ALL dirt and grime around the area BEFORE doing any work.
Be careful not to drop any bolts, plugs, hose clips or tools down the engine compartment.
Be careful dirt and grime doesn't fall into engine block when plugs are removed.
Do not drop the spark plugs on a hard surface as it will damage them.
Drivers side plugs are more of a pain to access than the passenger side plugs.
My ride has 67,000 miles and most of them have been highway.
I have a 2008 Sport Edition V6.
4th gen were first 4Runners with aluminum engine blocks (I think?).
Steps I took to replace each side of spark plugs: (passenger side first)
1. Pop the engine hood. At this point I always lay a towel over the fender to help protect the paint. It also helps to keep your shirt clean as you lean over to access certain areas of the engine compartment. I chose to remove the plastic cover on the engine, although I don't think this is required to reach the plugs. There are two 10mm nuts to remove the cover.
2. Reposition the engine air filter for access. Pop the two clips on the engine air filter and carefully push the engine air filter out of the way. You can now see the ignition coils.
3. Unclip the electrical wires. Use a small flathead screwdriver and carefully unclip the electrical wires that are plugging into the top of the ignition coils. My clips were extreme tight and it took some careful prying with the screwdriver. I had to squeeze the little release mechanism really hard and then I placed the screwdriver in the small gap between the male and female parts of the plug and then gently rotated the screwdriver (like I was unscrewing a screw) to force the plug out. If you can't mentally keep track of which wires go on which plug, you should label them accordingly, immediately after removing each one. Toyota makes it relatively easy though as the placement and length of the wires really dictate exactly where they should go.
Middle electrical wire I bent back to get it out of the way.
4. Remove the bolts on the ignition coils. Grab your small socket wrench and remove the three 10mm bolts holding in the ignition coils. There is one bolt per coil. I used one with a short handle because it works well in tight areas. Although the bolts are the same size, I prefer to keep them ordered and place them back into the same hole from which they came. So be careful to label them if you want to replace them in the same hole.
5. Remove ignition coils. This is easy. Just pull up on each one to remove out of the spark plug wells. It is important to note here that BEFORE you remove these, all dirt and grime should be thoroughly removed from the area. You do not want dirt and grime dropping into your engine block as you pull out the spark plugs. There is also a rubber washer that might be a little stuck to the engine. Be sure to gently remove these with the ignition coils. I was also careful to keep these in order as well and replaced them in the same well from which they came. It's probably not necessary but I prefer to do this anyway.
6. Now remove the spark plugs. You can see the park plugs down in the wells. Grab your large socket wrench with extender and carefully loosen each plug. Turn counter-clockwise. (Please note, my 5/8" deep well spark plug socket did not have the rubber insert that sometimes comes with these special sockets). I loosened each spark plug about 3/4 of the way out. Then I took a 10" piece of clear vinyl tubing and pushed it gently down the well and onto the spark plug until it snuggled onto the top of the plug. Then I simply rotated the hose a few times to remove each spark plug. You'll notice that my tubing is curved. That's the way it came off the roll at the local hardware store. To fix this, I took my long but narrow screwdriver and slid it into the tube. This helped keep it straight while rotating the tube to get the spark plug all the way out. I found out on the first plug that if you use the ratchet to unscrew the plug all the way out, then it falls (tilts) against the edge of the well and it's more difficult to get the tubing to slide onto the top of the plug.
7. Now install the new spark plugs. I used to the vinyl tube trick to get each plug started when installing the new plugs and screwed them in with a few turns of the tube before switching to the socket wrench to tighten all the way down. I tightened them pretty good but I was very gentle and careful not to over-tighten.
8. Reinstall the coils carefully. Don't forget the rubber rings.
9. Reinstall the 10mm bolts that hold the ignition coils in place.
10. Reattach the wire plugs to the ignition coils.
11. Reattach the engine air filter.
****
Now for some notes on replacing the drivers side spark plugs.
First, the drivers side was quite a bit more difficult to access. I started out by cleaning the area. Quite the pain. Luckily my hands aren't that big so I could get my towel in there and clean things up ton remove the larger dirt particles. This side had more grime on it than my passenger side for some reason.
Second, I removed only the vacuum hose and some electrical plug, as indicated on the photo below. At first I thought I was going to have to remove much more, but you can get it done by only removing the hose labeled below.
Third, the removing the middle plug on this side was an absolute *****. There is barely enough wiggle room and you have to use one hand to bend hoses out of the way while holding on to the damn ratchet extension while trying to make little tiny 5 degree rotations back and forth. It took me way more time to get this one out than all the rest.
After you're finished with the plugs on the driver side, don't forget to plug in the small electrical connector and the vacuum hose. Fire that puppy up and if it starts, you're done.
****
Extra notes.
For my OEM plugs I had three Denso plugs on the passenger side, and three NGK plugs on the driver side.
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Thanks to the OP for the guidance. Btw I encountered the denso and ngk combination too. I also purchased a magnetic spark plug socket so had no need for the plastic tube...Thanks all for the encouragement and insights! This forum rawks!
