FlexyLexi

Just bought a GX470 from the original owner with 216k miles. He had all the service records from the dealer (90 pages!), and I couldn't find any evidence of the plugs ever having been changed . So, I decided I better do it. I went with the NGK iridium IX which was ~$7 a plug. There are more expensive iridium plugs but who knows what the difference between "laser" and "IX" is. Everything went pretty smoothly. Only tip I have is it would probably be slightly easier with a cool engine...I was playing hot potato with the plugs and plug wrench lol!

dchan865

I was amazed that the spark plugs last so long for the rig. I had my original ones replaced for the 1st time recently at about 215K miles when I had my timing belt done. Most of the mileage are freeway miles so not sure if that help with the longevity.

FlexyLexi

Mine seemed to be in decent shape too. Still probably a good idea to change them more frequently-you don't want them to get seized in the engine block!

deeken

Just replaced my plugs last night. Took me about 2.5 hours to complete. I took my time doing it and wasn't in any hurry. I cleaned up all the connectors and added dielectric grease for a nice, secure connection. The original plugs were NGK laser Iridium's. I replaced them withDenso SK20R11. When I first started up the car it started revving up high around 2.5k RPMs and started to fluctuate from low to high. I thought I broke something. Eventually it settled down around 1k. I took it for a little spin and it seemed a little peppier. I also cleaned out the throttle body while I had the intake off. One less task for me to complete.

bkingsle8

Nice write up - OEM plugs is the way to go (NGK/Denso)! Definitely do this on a cool engine, if the heads are hot, and the plug threads are softer, you run an increased risk of cross-threading them if inserted wrong.

RockfordRX

Here is my experience:

BCriss

Hello All,

I have used this forum for several years but first time posting. First off thank you to all of the dedicated posters who have written DIY's! I finally got around to doing the spark plugs today and came across this coil pack and spark plug which are severely discolored. It seems like the plug may have been loose for quite a while. Should I change out the coil or try to clean it up and properly torque the new plug. The spark plug hole on #5 is also severely discolored.



Thanks for the input!

chiph9

If the threads are clean, I would go ahead and thread a new plug in there by hand until it bottoms out and is snug. Only then would I whip out the torque wrench.

If you aren't getting misfire codes set, you could keep using that coil pack. But I hate the sight of it and would replace it, personally.

Was the old plug wet with oil? If so, time to replace the spark plug tube seals and valve cover gaskets.

Chip H.

BCriss

Plug and Coil pack were dry but coated with dark brown dust...

BCriss

I got the plug snugged hand tight. It did seem much more loose than the other plugs on that bank.

IanB2

I'd maybe put that coilpack on a cylinder that's easy to reach, in the event it does cause misfire codes in the future so it's easy to swap out for a new one. With any luck you'll even notice a performance/economy increase with the sparkplug being tight in the head, lol.

Lexus4321

Check out using the NGK G plugs.

Works fine for me, I replace plugs at about 75kmi, about to be on my 3rd set. And over 224kmi (2006) I have used all types of gas.

NGK 7092 BKR6EGP G-Power

BCriss

I was able to torque the spark plug to 17.5 Nm and cleaned up the coil pack as best as I could. Seems to run much smoother now. I always heard a slight tick and I'm wondering if that wasn't a tiny amount of compression blowing by the loose plug.

DMV703

Hey All,

I replaced my spark plugs over the weekend using these instructions: https://www.clublexus.com/forums/gx-...-gx-470-a.html

Everything went smoothly but after putting everything back together and starting the car, the drivers side window switches aren't working. I can open my drivers side window and the sun roof seems to be working (although the auto open/stop isn't) but I cant operate any of the other 3 windows with the drivers side switches. Only the individual door switches for each window.

Anyone have an idea as to why this may have happened? I did leave the drivers side window down when I originally disconnected the battery to work on the car (to reach inside and grab tools etc.).

ALSO secondary note: I'm replacing my rear shocks soon. one of my rear height sensors is malfunctioning and I'm wondering if its worth replacing the sensor or just doing the coil conversion when I do the shocks? Lexus wants $700 to do the sensor. Thoughts?

Thanks.

NEPAKevin

Anytime the battery is disconnected, the windows have to be reprogrammed/reinitiated. Procedure is in the manual and there are lots of videos on youtube, etc. as well as threads on this forum on how to do this. Short version is you go to each window and the sunroof and run them all the way down and all the way back up. Has something to do with setting the auto up/down feature("I don't know tech stuff"). Sometimes the window vent shades I have interferes with this and I have to hold them out until the window goes all the way up.