mmatheny

Can the rear bank plugs be replaced without removing the intake plenum?

03 ES

yes. it is very possible but also a pain in the a$$.
you also need to have the right tools as well, and a great deal of patience.

mmatheny

OK - another question - is the plenum gasket metal?

ASG14

iTrader: (1)

Yes, it;s metal, BUT I;d still replace it if it has high miles. It should be around $12-$16.

Exactly.

llcoolpass

no need to replace that gasket. and i prefer to take the IM off, myself, to do them... but you technically don't 'have to'

and here is the thread that will help answer the yes portion of your question:

https://www.clublexus.com/forums/es3...ug-change.html

mmatheny

Yeah, but I have the plug over coils - little more involved than just a plug wire. Think I'll just pull off the plenum, then I can check other stuff also.

mmatheny

Actually, this is all conjecture - my iridium plugs only have around 45k on them - I pulled the front 3 and they look great.

mmatheny

Yeah - these Jap cars need a hot plug - the Bosch don't run hot enough. NGK all the way.

llcoolpass

and these 'jap' cars run, on whatever they were designed for, best. it's worth knowing that some spark plugs are pretty crappy, and bosch has had some notable failures in the past in quality control. NGK and DENSO are what toyot... lexus recommends.
the NGK iridium plugs are some of the best plugs available. They should last the life of the engine. doesn't mean you shouldn't remove them and check them out every 5 years [maximum] to make sure that they dont get too attached to their home, if you know what i mean. and don't forget to gap them, if youre skilled and brave enough. i did. i f-ed one of them up. 7 dollars down the krapper.

capnfred

when you install the plugs put some high quality aluminum anti seize on the threads, then tighten them with a torque wrench.... they don't get tightened very much.... w/o looking it up 13ft/lbs sounds right... but I would look it up just to be sure... as for the plenum... its sooooooooo easy to take it off... and will save your temper and bruised knuckles... my experience with the gasket is that its very re-usable... I have taken off and rplaced my plenum more times than I want to think about t/s a miss, that turned out to be a combination of bad bosch plugs and a bad ecu..... but that is another story.

capn

mmatheny

Do you put any kind of gasket seal on the plenum gasket when you reuse it?

ASG14

iTrader: (1)

^ No, just hope that it's still perfect is all. If you need to put a sealant on it, it's not good.

capnfred

The gasket appears to be stainless steel with a plastic or rubber coating, as long as the coating is intact it can be reused.

ASG14

iTrader: (1)

^ It's not a plastic or rubber coating. It's some sort of hard paint.

capnfred

never looked at that close.... if the coating is all there then is seems to be ok... hav'nt had any problems with it... but if your worried its not expensive at all....