Spark Plug Wires on my 02' Toyota 4Runner 3.4 L V6.

Well, today I had a small battle.  I did my spark plug wires on my 02' 4Runner.  This one is pretty easy to work on as you can see by the straight shot of the engine bay (with a little Southern Utah sandstone mud from four wheelin'):

Toyota products are some of the easiest to work on for most repairs (at least from my experience).   This job was no exception.  One of the reasons why Toyota has made some of the most reliable vehicles on the road is due to their simplicity.  This engine above is no exception.  If taken care of, these engines go 400,000 miles without any major work done. 

Since my 4Runner engine is non-transverse mounted, it was easy to take pictures of everything I did.

First I acquired the necessary parts:  

Top is the spark plug wires, bottom is dielectric grease.  Many people skip the dielectric grease, but I think it is important.  It's purpose is to grease all the connections between the spark plugs, and the spark plug wires.  The grease is special because it conducts electricity, and since these wires will be in here about 50,000 miles before I change my spark plugs again, it will make it much easier to remove the wires when the time comes.  When the spark plug wires can not be removed because the dielectric grease is omitted, they can break upon disassembly later.  The grease was about $1, and $1 well spent.

Next, the acquired the tools, which I owned already:

The tools necessary to do this job are:  pliers, Phillips screwdriver (plus sign), common screwdriver (flat blade), socket set, needle nose pliers, a 11" x 3/8" ratchet extension, a 6" x 3/8" ratchet extension, ratchet, and spark plug socket.  All these tools are very common and can be acquired with ease at any tool store. 

First I removed the air intake hose (circled in red):

I undid the clips that hold the wire onto the air intake hose.  The clips are marked in green.  To do this, I used my needle-nose pliers.  I then loosened the clamps with my Phillips screwdriver (circled in blue). The air intake hose is now ready to be removed from the vehicle.

This is the result:

Now we are ready to change the spark plug wires.  Here is where my brother failed.  You only do ONE spark plug wire at a time.  DO NOT REMOVE ALL THE WIRES AT ONCE.  Each wire has a specific place, and if you can't remember where it goes your car will not run right or at all.  It doesn't matter which wire you do first.

When my dad was in high school, his friends thought it would be funny to remove all the spark plug wires and throw them on the ground while he was at a school dance.  His car was a V8 so he had 8 spark plug wires to figure out where they went, in what place on the engine and what length of wire went where.  It took my dad and my grandpa (who is a retired mechanic) hours to fix his car and make it run again.  In my 4Runner, it has a different setup.  I have 3 spark plug wires for 6 cylinders.  This is due to these special coil packs.  The coil packs say "Toyota" on them in the picture below.

I removed the three bolts holding the coils down onto the engine (circled in red), removed the connectors going into the coils (green) then I removed the spark plug wire connector (blue):

Since we are dealing with electrical connections let me give a huge caveat.  DO NOT force apart any electrical connection.  Take your time and figure out how it disconnects before you start tugging on them.  NEVER pull on the wires themselves.  In this picture above, the green circles have a tab that push in.  Using my thumb, I pushed in on the tab and pulled out at the same time.  DO NOT use dielectric grease on these connections.  Since they are well covered with the plastic connector, it is not necessary.  The connectors came apart easily with no trauma:

I then pulled the coil pack out, it has a long tube sticking down on the underside of what you see in the picture.  Next the spark plug wires have to be disconnected and were a little tricky.  I removed ONE wire at a time.  They disconnect by not pushing in on a tab, but inserting my flat blade screwdriver at the bottom of the spark plug wire connector and lifting up.

I then followed one single wire to the other side of the engine:

To make things easier, I did remove the small bolt (10 mm) and the "DIAGNOSIS" connector above and to the right of where my hand is.  As you can see, the wires are different on this side of the engine.  To remove these, you twist and then pull up where the wire goes into the small circle.  DO NOT pull up on the wire itself.  Twisting the wire before pulling breaks loose the connection to make it easier to pull up.  With one wire removed from the vehicle you get this:

I then removed the spark plug using my 11" x 3/8" ratchet extension.  I acquired a special extension where it locks the socket in place.  The spark plug socket has a piece of rubber in it to hold the spark plug in the socket so when you pull the spark plug out, it comes out with the socket.  When installing a new spark plug without the locking mechanism, you can pull out just the extension and not the socket.  It is a little frustrating to try and pull out your socket by itself. 

I then put a little bit of dielectric grease on top the spark plug where the wire is going to connect to the wire.  I then put the spark plug back in the engine.

To install a new spark plug you apply a high-temp anti-seize compound onto the threads of the spark plug.  It looks like metallic grease.  I then put the spark plug into the socket attached to my extension.  ALWAYS start threading the spark plug by hand.  If you get immediate resistance, you have the spark plug cross-threaded.  Loosen it and try again.  There should be minimal resistance for a few turns.  I then tightened the spark plug with my ratchet.  I put a fair amount of torque on the spark plugs.  DO NOT ratchet them down until you can't turn the ratchet anymore.  THIS WILL CAUSE SERIOUS ENGINE DAMAGE!  You want the spark plugs to be tight, but not super tight.  A too loose spark plug can loosen itself, cross thread, and tighten itself.  If you tighten them too much, you can strip the threads out for the spark plug.  Either way, the threads for the spark plug are deep within the engine and require a tedious and expensive process to fix. 

Now it was time for a new spark plug wire.  All the new spark plug wires had different lengths.  So, with the old wire and the new wire side by side, I could easily see which one it was:

I then put dielectric grease on the small end (right side in picture above):

I used my finger to move the grease all around the silver part in the center.  I ran the wire where the old one used to be.  I made sure that the new wires were well connected and tight by pushing down in the center of each end of the wire.

I then ran the other 2 wires and put dielectric grease on the 4 remaining spark plugs using the same procedure I have explained.   I put dielectric grease on all the connections between the spark plugs, and spark plug wires.  On the left side (driver side) of the engine, it was a little bit more hairy to get the spark plugs and wires out.  For the remaining 2 wires, I did have to remove some brackets and move some other things out of the way.  In my opinion, it makes auto repair much easier to move things out of the way if you can.  This gives you room to work, just remember where everything goes when you put it back together.  You shouldn't have any bolts left over.  This picture shows what I thought was necessary to move out of the way in order to change the spark plug wires.

On the left of the picture, I already removed that bolt.  The bottom circles a bolt that connects that big black bracket that runs to the top of the engine.  I loosened the bottom bolt and undid the top bolt (indicated by the red arrow).  This allowed the bracket to swing toward the back of the engine to get it out of the way.

I then put everything back in it's place in the order I removed it.  Many removal procedures in auto repair are this way, but don't always assume that it is.  

Next, I double checked my spark plug wire connections, and started my truck:

It runs beautifully!  If the engine doesn't run right, shut off the engine, and double check all your connections.

Me = 4 Cars = 0.

Next post will probably be front brake pads on my 2000 Honda Accord EX V6 Coupe.  I took it in for inspection yesterday and they are getting pretty low.  I got an "Advise" on my inspection report.