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Spark Plug Change 1MZFE Engine - The Easy Way
Lots of posts here on doing the back 3 plugs, removing the air intake and parts, hoses, etc. Absolutely not necessary! Those 3 plugs can be changed in less than an hour, the front 3 in about 15 minutes.
I guess some of the posts recommending removal of the air intake and associated parts were directed at fixing a valve cover leak, which be a no-brainer to do plugs while the top of the engine is clear. Regardless, this is a greatly exaggerated job in terms of difficulty IMO. I postponed it for 6 months needlessly.
I'm using Toyota's cylinder numbering, which is 1,3,5 for these hard-to-see plugs, viewed from the front of the engine.
1 3/8" drive ratchet
2 6" extensions
1 5/8" sparkplug socket (has a rubber insert to hold the plug)
1 3/8" drive torque wrench.
1. Set up some lighting to illuminate behind and under the intake. Grip the plug cap for #1 and pull it firmly up, off the plug. Get it out of the way of the tube. Do the same for #3 and #5. I removed the wires from the little holder to make this easier. The 3 plug tube holes should now be easily visible. The cap removal exercise will familiarize your 'mechanics hands' with the 3 plug holes. Most of what follows is done by feel, as you won't be able to see much while you work.
2. Attach a 6" extension to the plug socket and fish it into the #1 plug tube/hole. Get it firmly onto the plug, attach the ratchet, and turn the plug out. Mine were very stiff, probably not changed in over 200,000KM's. Remove the ratchet, then the extension with the socket and plug.
3. Remove the nut holding the PS hard-line hose to the intake. Fish the 6" extension and socket into the plug tube for #3. Insert the second 6" extension into the first, then the ratchet to turn the plug out. There is plenty of room to work, the ratchet will just fit next to the cowl welting, above the intake. When it's out of the threaded hole, detach the second extension and remove the plug/extension/socket from the tube.
4. #5 is the same drill as #3, except there is no PS hose in the way of getting a straight shot at the plug, but you may find this one easier to work at from the driver's side.
5. Put some anti-sieze on the threads of the new #1, insert in the socket, fish it into the tube and start the plug by hand 2-3 turns to ensure it's not cross-threaded. Attach the ratchet and turn it in all the way. Set the torque wrench to 13 ft lbs and torque it in place.
6. Do the same for #3 and #5, using 1 6" extension to get the plug started, then attach the second extension and finish with the torque wrench.
7. Replace the caps, the PS hose bracket nut, and put the wires back into the little holder. #1 goes on the bottom. I also dabbed a bit of die-electric grease on each plug tip before inserting into the socket.
8. The front 3 plugs, #2, 4 and 6, are super easy. Just detach the 2 wire leads from each coil, undo the 10mm bolt, remove the coils and change the plugs.
I measured the plug gap on the new plugs (Denso double electode platinum) at 1.12mm. The old ones were 1.22mm. They were all a nice light brown colour though, so I think the engine is in good shape.
Last edited by donbryce; 04-22-2009 at 05:54 PM.