Well it's done. You can replace the plugs on your RX330 without removing the engine. ( I ran mine 140,000 miles)
6 iridium plugs. Mine spec'ed Denso 90080-91180 that I got from a Toyota dealer for $10 each (Lexus wanted $14)
Note: do not gap the plugs as you will ruin them.
1 PCV Valve
1 Air Filter
1 Can throttle body cleaner spray
1 quart coolant
1 tube permatex anti-seize (small)
1 tube blue loctite (small)
1 3/8 flex head ratchet
1 3/8 regular ratchet
1 5/8 spark plug socket
1 6" 3/8 socket extension
1 10" 3/8 socket extension
1 10mm 3/8 socket
1 12 mm 3/8 socket
1 5mm allen head socket
1 10 mm open end/box end wrench
1 19mm open end box end wrench
1 pair of pliers
1 pair needle nose pliers
2 phillips screwdrivers (1 long 1 short)
2 flat bladed screwdrivers (1 long 1 short)
1 piece of rubber tubing 8" long that will fit snugly over the top of the spark plugs but still pull off.
1 pack of stick on labels & sharpie marker
1 trouble light
1 small wire brush
3 shop rags
All instructions are oriented to be facing the engine (battery on your right)
ENGINE MUST BE COLD
Remove black cover (4 push clips) and put to the side.
Remove the silver engine cover 3-5 mm allen nuts ( note the nuts screw over studs so be careful to lift the cover easily) There is a spring clip underneath the cover ( right beneath the Lexus logo) that pulls up an off. There is nothing to detach as it pulls straight upward. Put cover to the side being careful not to lose the allen nuts.
You will now see the front bank of plugs. Do one at a time. Remove 10mm retaining nut on coil. Unplug wire connector from coil. Wiggle the coil by turning slightly to break it loose form the plug. Pull upward and the coil & boot assembly will come right out. Using 3/8 ratchet & long extension break plug loose and unscrew a few turns until it turns freely but do not remove plug. Remove ratchet and slide rubber tube over end of spark plug and finsh removing the plug.
(Note: I removed the rubber insert form my spark plug socket for fear of having it stick to the spark plug inside the plug well.)
Coat new plug threads LIGHTLY with anti-seize and use rubber tube to get the plug started back in so as not to cross thread. Tighten with 3/8 ratchet ( you can torque the plugs on the front but don't expect to on the back side). Re-install coil and wire clip and 10mm retaining bolt
Repeat for other two front plugs.
YOU ARE NOW 20% DONE :-) Take a coffe break The real work is just ahead.
Remove air filter top cover and set to the side. Number each rubber hose and connection point with labels for ease in re-assembly.
Remove ALL air intake hoses & plastic pieces in front of throttle body. Number hoses & connection points again
Unclip electronic plug from front half of throttle body and push out of the way. Remove all hose connections to throttle body. Two are coolant lines so you will lose some coolant (put a rag under the open hose ends as they will continue to drip) Label all hoses & connections.
Remove front half of throttle body (4 bolts) and place aside (label bolts)
Remove the throttle body bracket bolt on the back half of the throttle body (1 bolt)
Remove back half of throttle body (4 bolts) and place aside (label bolts)
Remove PCV hose & unscrew PVC valve & remove (discard)
YOU NOW HAVE ACCESS TO THE REAR BANK OF PLUGS... (this gives new meaning to the term reacharound :-) )
When replacing the rear plugs do not disconnect the wires from the coils or you will have difficulty getting them back on. If a coil tube assembly is stuck use the long flat bladed screwdirver to GENTLY pry upward on it. It will come loose. You will have to push them out of the way to R&R the plugs. There is not a lot of room to work but it can be done if you are patient. This where the rubber tubing is a lifesaver and be sure to use anti-seize. I was able to get the driver side plug & middle plug form the drivers side and the passenger side plug from the passenger side. If there are vacuum hoses in your way remove & label.
Clean throttle body ( do not spray the black electronic plug on the front half)
Install new PCV valve
Install new air filter
Re-install everything in reverse order using loctite on the throttle body bolts.
The new PCV will come with sealer on it. If not use loctite.
NOTE: The Haines Manual says you need to remove the plastic intake manifold. NOT TRUE.