wpbmed

Does any one know if anything other than the upper plenum needs to be removed in order to change the rear plugs? Does the intake have to come off? Just want to get the gaskets before I tackle changing the plugs. Thanks in advance for any help.

oldgrump

Basically the plenum only. You might also want to remove/separate the throttle body from the plenum which will allow you to leave the throttle body connected to it's coolant hoses and harness connectors. You may have to work around/move aside a couple of large harnesses etc. Ensure that you vacuum any dirt/grit from each spark plug tube after removing each coil and before removing each spark plug. This may be of assistance to you: http://lexus.sewellparts.com/oem-cat...S350-2011.html

wpbmed

cool thanks!

frankbcnt

i just changed mine and didnt remove it. only 1 plug was a pain but still wasnt too bad with a swivel. I did 5 of them in less then 10 minutes and the last one prob took 5 minutes itself.

oldgrump

I looked at the space available and it looked like the coils were more the problem than the plugs.

Paul3637

Over on the toyotanation Camry forum, someone with the same engine as lexus ES350 on a 2010 Camry changed them & posted pictures, links to how to videos on youtube, etc. He changed them at 80,000 miles and the lesson learned is that the plugs are good for the full 120,000 miles as instructed by the Toyota/Lexus maintenance guide.

http://www.toyotanation.com/forum/10...nterested.html

frankbcnt

I changed mine out at 45k and yes they were still good but I see that one plug looks like its halfway fouling. I think maybe one of my coils is getting weak.

wpbmed

Thanks for the info, I appreciate it. But I have to disagree, there is no way the plugs can last for 120k miles. It's just not reality. That is the car manufacture making that claim, and stating that leaving them in there for that long will not void their warranty. Check with the maker of the plugs, and they tell you a different story. The physics and chemistry just will not allow the plugs to heat up and cool down repeatedly while firing billions of times over the course of thousands of miles. I tell you from experience, my dad had his own shop for 35 years, with master techs working for him. I have seen with my own eyes hundreds of cars with problems which stemmed simply from falling for the hype being passed off as fact now a days. You can't leave coolant in a car for a 100k miles, you can't leave oil in a car for 15k miles, you can't leave spark plugs in a car for 100k miles and expect to keep the engine in top running condition. Do a little research on the net and you'll see 60k miles for iridium is expected. After that, you're wasting gas. (Don't go to the denso web site, look at independent reviews)

frankbcnt

Yea it's really not that hard to change them. I don't bet against them lasting 100k but that doesn't mean they are performing at 100%. For 45 bucks I'll change em out.

dreyfus

I just changed mine out at 120,000 and they were fine.

LexBob2

Did you notice any change/improvement in performance or gas mileage after the plugs were changed?

dreyfus

That would have been nice, but no. It has only been a couple of hundred miles since the change so I'll pay attention to see if my mileage improves.

wpbmed

Don't know how in the world you possibly changed the rear ones without taking off the upper intake, but I had to remove mine, as well as the strut bar. Which brings up the next question, does anyone make a better strut bar for the ES?

oldgrump

Why don't you like the strut bar?

wpbmed

Its cheap, want a stronger piece