I already changed the front five plugs in my 2002 Xterra SE 4x4, here's what I did for that hidden 6th plug...

I Searched this and other Forums, got a bunch of tips, and today I got that 6th spark plug changed.

Here's what I did -

1. Blow out the back of the engine with an air hose. Now remove the hood. Oh come on!!! It's only 4 bolts and a w/w hose!!! What I did to make it easier to get back on was to drill two "D" letter size holes through each hinge & hood and cut the threads off a 1/4" x 2" socket head cap screw so I could quickly align the hood hinges when I replaced it.



2. Now I could lay on top of the manifold and get my hands in the space between the manifold and the firewall, after I unbolted several brackets holding throttle cables, ABS lines, and a vacuum hose. I used a cut up large cardboard box to lay on. Here's the brackets I removed/moved.



3. I used two 6" x 3/8" drive extensions and a 3/8" x 5/8"
universal spark plug socket with a 3/8" universal between the two 6" extensions. I duct-taped all these together. I used a 1/2" ratchet with a 3/8" to 1/2" adapter for breaking the plug loose.

4. Pushing all the cables, wires, hoses and brackets out of the way, I was able to get my left hand in an opening behind the passenger side manifold -



- and feel the plug wire, and by pulling the lead with both hands get it off. I could just feel the top of the spark plug to guide the socket down to it, and tap it in place with my hand. I put a piece of scrap wood between the firewall and the extension, pressing the extension up against the manifold, and applied pressure to the ratchet. It came loose, and alternately tightening/untightening it for a few turns, it came free. When it starts squeaking, you know it's good to come out.

5. I never-seized the new plug, and guided it down to the area where the hole was (I couldn't see the hole itself) with the socket/extensions. Turning it in by hand, with the extension tilted slightly back and to the left, it went in easily. Tighten it up, re-attach the plug wire, pushing down until you hear/feel it click in place on the plug. Remember to angle the lead back & to the left also or it won't go on.

6. Reassemble all brackets, hoses, and clips, and start it up and check it out. Shut it off, put a couple old rags or cardboard above where the hood hinges are, put the hood on top of the engine, and prop it up in place with an old broomstick or board. Start all 4 hood hinge bolts, then stick the SHCS pins in the drilled holes and then tighten all 4 bolts down and remove the SHCS pins. Replace the w/w hose and it's done.

Thanks to all here for the tips!

I had the shop do it when they did my timing belt. Just didn't tell them what a pain it is.

Jeff!

Wow, that's a lot of work for just for one plug. I just used of extensions, a swivel, and something to cover the engine and got it done in a 20 min of fiddling. Done this at least 5-6 times without any issue.