Where are the spark plugs on a 2001 Toyota Highlander?
The 3.0L 1MZ-FE Engine, California, Highlander Limited V-6 Like
many Japanese cars, they are screwed into the top of each cylinder
head. The 3 spark plugs closest to the front of the car are
recessed deep through the valve cover, so you must first remove the
flimsy plastic engine cover (held in with Allen head nuts), and
remove the three (3) DIS (Distributor-less Ignition System) Spark
Plug Connectors from the Valve Cover. The DIS Spark Plug Connectors
are each held in place with a single 6mm bolt (so they don't come
loose). If you look down the "Tube", you will see the top of the
spark plug. The other three spark plugs are in the rear side valve
cover and have the same DIS Spark Plug Connectors and bolts.
Unfortunately, the Upper Intake Plenum and Throttle Body must be
removed if you need to get to these spark plugs. Also, to remove
the Upper Intake Plenum and Throttle Body, the Strut Tower Brace
has to to be removed to give you enough room to work.