It's a very simple DIY, at least compared to my 2nd gen GS. Just remove the engine cover, remove the intake tube, and there you go. There are also a ton of videos that show how to do it. That being said, there are pretty serious/expensive consequences if a person messes up, so $220 might be worth it for some people.

 

Yeah I have seen spark plug replacement videos before, but I'm just not too sure about the parts where they have to gap the spark plugs and "tune" the engine. Probably best to leave it to the dealer for the peace of mind.

 

$220 is actually pretty cheap, compared to getting it done on a transverse like a Camry V6 (2GR-FE) which takes twice the amount of BS to get to the plugs (because the ones in the back are blocked by a ton of components) Most places have wanted like $400+ to do the plugs on my Camry.

That said... it is pretty easy to do yourself if you get the correct directions and have a torque wrench.

-Mike

 

2013 GS350 Maintenance schedule

I made this from the published schedule, easier to view in table form.

 

I would change the spark plugs at the recommended 60k interval. The 58k mile spark plugs that I pulled from my car were starting to show a quite a bit of wear on the center electrode. Plus, if you are under warranty and anything happens to the engine they will look for any excuse to deny warranty -- not following the service interval will fall under this. Changing the spark plugs on a GS350 is super easy and can be completed in under an hour. If you can do brake fluid flushes and oil changes then you can definitely change the spark plugs in this car. Other fluids to consider changing would be differential and coolant. Lexus claims the transmission fluid is "lifetime" but I find that laughable.

 

I am thinking about doing a transmission drain and fill...any tips would be appreciated. My '13 F-Sport AWD is about to hit 70K, so not too worry about warranty anymore but would like to change the spark plugs to get it out of the way. Dan, would you able to put together a Youtube video of how to change the spark plugs? Or pics of the plugs locations? I changed the plugs on my wife's car before, after the dealer quoted me my right arm and left leg. So I know it won't be hard, just need to know the locations of the plugs on my car. Love your videos on Youtube, man. Thanks!

 

Spark plug change is recommended under the Emissions Control Warranty.
It merits inspection but not necessarily replacement.

Also what changed about the spark plugs? My GS430 had 100-120k before recommending a plug change.

 

My dealership said that since we had both "ported" and "direct" fuel injectors, the spark plugs take a beating during normal operation for 60,000 miles and should be changed at that point.
Since I can do that work myself, I did change them all and noticed no change in measurable performance.
The engine idled just a bit smoother, but there was not an increase in mileage.

I saw some wear on the old spark plugs, but nothing dramatic. But since I live here in California I'll change the spark plugs at 60000 for emission purposes.

On my prior GS350, (at 2010 model) I did not change the spark plugs at 60,000 miles because I didn't know I had to do it. Since my first 2 GS vehicles were older GS400's, I only changed my spark plugs at 90000 miles along with the timing belt.

So I'm still on the fence about the need to actually change them, but I'll do it to be in compliance with emission laws.
Just my $.02