Photo of the six plugs, original from the 2011 with 230K km. Threads were oily but not the electrodes.

 

Those spark plugs look to be in great shape. Denso and NGK iridium plugs have been known to last the life of the vehicle.

 

You just need spark plugs to ignite the fuel and I've never had a failure using Denso or NGK on my 500hp Mitsu Eclipse so Im sure they be great on a stock RX.

 

Pulling the windshield wiper mechanism and tray is actually the same procedure the Toyota repair manual (TIS) shows for the 10-15 RX.

 

Thanks for providing the link.

 

I was just curious the difference between the Lexus and the Toyota dealer price quotes for the spark plug replacement so I called to get a comparison and Lexus wanted $960 vs Toyota's quote of $250.
Do you think the Toyota dealer is going by what they charge for the Highlander?

 

If you've ever looked at parts, you will quickly realize the same part is always more expensive on the lexus websites vs toyota. Luxury vehicle and they want to take a bit out of your luxury wallet.

$250 isn't totally insane, but I would still do it myself.

 

Can anyone please help confirm the gap for the spark plugs and the socket size for the spark plug socket?

Thanks.

 

My car is Rx350 2011 and it had 100.000 miles on it. I just did this job last weekend. I started with the non intake manifold removal procedures and then switched to the one requiring removal of intake manifold. The reason for that was I could not disconnect the connector on the middle rear spark plugs and the one closest to the driver side. Here are some takeaways if I have to do that again. The picture of the 6 spark plugs attached for your reference.

1. The Sparkplug socket size is 5/8. I asked and no one answered me :-(
2. Using a needle pliers to press on the connector tab. This makes it super easy. I did break 4 out of 6 tabs with the hand press method. With the plier, I did not break the last two in the back and it was fairly easy to disconnect. One hand pressing the tab with the needle plier while the other one pulling the plug. You dont have to go forcefully with the tab. I used the pier from Husky with medium length handle (not too long but no too short). I applied just enough constant pressure so I can see the tab lifted up on the other side.
3. I did not have to gap the spark plugs. It came pre-gapped although I did check the gap with the gauge and it matched with the ones I pulled out. Maybe I was just lucky.
4. If I do it again, I am going to use the intake manifold removal procedure. The other method I dont think worth it for the vehicles with so many years on it. All the connectors were so hard to remove even when they are there in front of your eyeballs.
5. The wiper were the beasts to remove. I needed to stop my job and waited for the Wiper Arm puller. It took me a few hours just to attempt getting it out by hand hammering it, tapping it. Nothing really heped. I even used Blaster penetrating oil, the one I used to knock the hardest rusted pluming bolts. It still stayed on tight. With the puller, it came straight off. You need to make sure you marked the positions of your wiper arms before removal otherwise it might take you sometime to work it out right when installing it back. Also, with the driver side arm, it might not have enough clearance for you to stuck the puller under the bolts like the other arm. What I did was using masking painting tape on the arm around the bolt so I was not scratching it. Then, I stuck the puller under the arm but higher next to the bolt.
6. Use Blaster penetrating oils or WD-40 for the bolts you can not remove.
   https://www.lowes.com/pd/Blaster-PB-...E&gclsrc=aw.ds
7. When removing intake manifold, make sure you have a clean rag or a lot of paper towel ready to make sure you do not contaminate.
8. Make sure when you lift the intake manifold. You lift it all the way up and not dragging it to the side because you can easily push all the dirts to the inside chambers. For my intake, there was some small animal wster on the intake manifolds and a lot of dirt accumulated over the time. Although I cleaned it up well before doing the service, there are small tiny gaps that I could not fit anything it to vacuum it out.
9. Make sure you buy intake manifold and throttle body cleaner before doing the job because you are going to need them. :-)
10. Make sure you do Star Patter when tightening the bolts.
11. It is best to have the gasket for the manifolds ready to replace. I reused it because I did not have it on hand but I cleaned it and the mating surface very well with the cleaner before putting it back. So far so good. Finger crossed.
12. If you can, buy a new PCV valve. It is cheap and if you are going to do the intake manifold, you can easily replace it.
13. Make sure you have a lot of zip ties handy to tighten the connector to the plug coil in case you break the tabs Below is a reference on how I zip-tied it up. Sorry for the focus, I was taking the picture of the radiator cap but I believe you can still see the ideas on the back
14. 
15. Disconnect the battery terminal before doing the work :-)
16. You dont have to disconnect the connectors on the 3 front spark plugs coil to replace them.
17. 

 

Since the gap on the old plugs is the same as the new plugs, does that mean that in reality, the old plugs were still fine and did not need to be replaced?

Was there any difference in the way the vehicle drives, now that the new plugs have been installed?

 

I tend to do more pro-active maintenance rather than reacting to what was wrong. The Denso spark plugs are well-known for lasting up to 150k miles but my car was 8 yrs old so I would rather change it before it is too late. Since you ask, I did not have any problems with my car before that however I do notice that my vehicle is now super quiet when idling. I could barely hear the car engine running. I am going to do 2k miles road trip so I would let you know after that :-)

 

The whole subject of "blown spark plugs" seems to be nonexistent here which is great.
Over on a Ford Truck/Triton forum, while not a common problem, there are incidents of spark plugs blowing out of the holes stripping the threads.
There are procedures and special tools for dealing with it.
My take on the Ford issue is the OEM plugs were torqued to 13-15 ft/lbs which contributes to the problem, besides the steel in aluminum thing.
When the plugs are left in for over 100K the likelihood of a plug working loose starts climbing, especially when there are 10 plugs, as in our Excursion.
I repaired #3 on ours when it blew out at 108K with a Timesert kit.
I've read of several repairs that have blown out a 2nd time because a helicoil was used, they don't seem to be able to handle the compression pulsing.
We generally torque the plugs to 25 ft/lbs and change them at 50K, but that doesn't seem to be needed for the Lexus which is great.
The plugs are a bit easier to get to in the Fords, the Gearwrench KDT41740 magnetic flex socket set below has been a big help.

 

Is this the apark plug issue wth Ford Triton engines you are referring to?

https://www.aa1car.com/library/ford_...ug_problem.htm

 

No, that is another issue with the later 3v heads.
The OEM Triton 3v plugs in 2004-2008 were a 2 piece plug and the lower section would break off if left installed for a lot of miles.
The lower section would get "stuck" in the bore from combustion crud build up.
Another set of extractor tools have been developed for removing the lower piece.
A replacement one piece spark plug is available (not sure if it's Motorcraft) that eliminates the problem.

 

I changed the front plugs a few months ago and was putting off the rear plugs so finally got to it yesterday. There are several videos on doing this, including the gold RX noted above. I used the video from the Car Care Nut (link below). He is a Toyota certified mechanic by trade and his videos are great. The video he did is on the same 2GR FE engine in my two 3rd gen RX's but looked to be a different model SUV. I followed his video to the letter with one exception. I did not remove the air filter box. I only removed the flexible 4 inch intake hose going from the air filter box to the throttle body. It's a stiff hose but easier than removing the filter box.

Removing the cowl provides a substantial amount of space and if you stand on the passenger side of the car, you can see a good bit of the rear of the engine. I can see how people would try, and do, this job without removing the plenum. With a good mirror, and lots of time, it can be done. I tried doing it this way at first but quickly realized the little things like removing the coil electrical connections, getting leverage back there to remove the coils and plugs, torquing the plugs, etc., would be frustrating and very time consuming, especially for the plug closest to the driver's side. Given that, I decided to remove the plenum. The Car Care Nut's video was excellent and showed just how easy it was to remove and replace it. The other nice thing about it was that he showed it was not necessary to remove the coolant hose from the throttle body so no need to mess with coolant. Once the plenum was out of the way, the plug change was fast and easy. 100% easy and worth it to remove the plenum. It's just a large piece of plastic with 3 gaskets on the bottom. I bought new gaskets for that and the throttle body at the dealer. I also cleaned the carbon off the throttle body while it was separated from the plenum. He had a video on doing that as well. It took about 10 minutes to do. Again, very simple to do and the car idles much more smoothly.

The car had 160k miles and the plugs were shot. I have 2 other cars with the 2GR FE that are around 100K miles so hope to be doing this for them by 120k. As far as time, it took probably 6 hours. I'm older, have arthritis and and not as flexible as I used to be so it took longer. Plus I was slow and deliberate and wasted time trying to get around removing the plenum. Doing it again, it would be much less time.

As someone else noted, the clips for the coil connectors on the rear bank plugs did not break. The clips on the front bank all broke. The hardest part of the job for me has been the very last step, reinstalling the wiper arms onto the wiper motor. I'm still trying to get them on. Hope it doesn't rain anytime soon.