kaloman

Hi Everyone,

I'm going to attempt changing out my GS350 spark plugs this weekend, but I can't seem to determine if anti-seize should be used or not on the plug threads. I've seen posts say both yes and no.

Does anyone have a definitive answer? Also if anyone has tips to making it easier. I'm basically going to follow the DIY thread from the IS forum.

Thanks in advance!

93SCMax

I can't say I have a definitive answer (there's always multiple opinions), but anytime you are going to have spark plugs in an engine for 100k, anti seize will certainly make it easier for the next person who changes out the plugs. Why risk the chance of breaking off a plug or stripping threads, possibly damaging the cylinder head? Far more work with these failures then adding anti seize when you change them out.

I use anti seize every time I change plugs on all my cars, and some plugs are changed every 30k. Never had a problem with the seal or removing the plug.

Just my opinion.

SILENTM

The thing is to not use too much. A thin coat around a few threads is good

MJG87

I would definitely do it, have changed plenty of plugs without it and it isn't fun, even after 15-20k kilometers. Have never seen it cause a problem if used correctly.

LoveThatV8

iTrader: (1)

Can this be used on 14mm bolts that connects the catalytic converter to headers?

MJG87

Normally for exhaust fittings you would use a high quality stainless steel through bolt. There is a type of Anti Seize compound for high temperature applications you can use but I am not sure which one would be best. From memory the spark plug stuff won't hold up to the heat.

ibidu1

iTrader: (1)

Not necessary on these engines, I did it without it. Ford engines have problems with their spark plugs they break inside the heads, because they use special plugs that you must use anti seize. The GS plugs are pretty standard normal style plugs. Just make sure to use oem or denso plugs, any other plug and the engine may run funny.

lobuxracer

iTrader: (2)

Lexus says no. I used to do this when I road raced motorcycles, but the plugs didn't last very long and frequent (less than 5k mile intervals) plug changes in those days would remove the threads in air cooled aluminum heads fairly quickly. With modern plugs (read platinum and iridium) the plugs are in the head for a long time. ND and NGK know this and build the plugs to stay put and not destroy the head when they are removed. Read what NGK recommends in their "Spark Plug 101". It will prevent you from making foolhardy mistakes based on Internet lore. Nippondenso also says no, do not do this.

MJG87

Great link and interesting bit of information. I have used Iridium's in a number of my vehicles (Evo/VR4/Skyline) and always used anti seize, of course making sure not to over tighten the plugs. I think it's just a habit and I have never read that information from the makers before telling me otherwise. Good link.

93SCMax

Great information from NGK and Nippondenso. Thanks for sharing! What's implied is that Lexus says no because NGK and Nippondenso don't recommend it. I'd love to see something specific from Lexus or Toyota...a technical service bulletin or factory assembly procedure.
If I don't use anti seize and pull head threads or break a plug later, I don't expect NGK or Nippondenso to warrant the failure. At 100k miles (1st change interval), it's far outside the Lexus warranty, so I'll continue to do as I have always done, be proactive and use the right amount of anti seize to reduce any possibility of not being able to get the spark plugs out later. Of course I heed all warnings and make sure the plugs aren't over torqued due to the addition of anti seize.

Once again, thanks for the spark plug manufacturers recommendations. Hopefully someone can share the "definitive" Lexus recommendation. Until then, I'll coat my threads based on personal experience. I'll keep this car a long time and will most likely be the guy changing the next set of plugs so my decision only impacts me. Other forum members can choose to use or not use anti seize based on the info presented. Either way, good points of view for opposite sides of the debate.

lobuxracer

iTrader: (2)

There is no admonition or endorsement from Lexus in the repair manuals, the owner's and technician's manuals, or in their technical training that I can find. I subscribe to TIS, so I can search anything and everything Scion/Toyota/Lexus. For the 2007 GS350 Lexus simply says:

(a) Install the 6 spark plugs.

Torque:

18 N·m {184 kgf·cm, 13ft·lbf}

MJG87

As an aside. Iridium plugs are usually "suggested" to last 100k kilometers between changes, personally I have never seen them make good in this, but I have usually seen them used in high temperature / high performance turbo applications. Do they recommend changing them every 100k MILES in the U.S, thats 60% more than the mileage of what they recommend to us over here in Australia. That is a huge number of miles.

93SCMax

I came up with the 100K from post #5 of the following thread. It states that Iridium plugs typically last 90-120K.

https://www.clublexus.com/forums/mai...nance-faq.html

In the US, Lexus "Warranty and Service Guide" states spark plugs being changed out at 60K to comply with the Emissions Control Warranty, which runs thru 80K. The Lexus dealer the car was purchased from recommended they be changed out at 100K, so my service was bypassed at 60K. The next spark plug change under the "Warranty and Service Guide" is the 120K service.

I apologize for mis-speaking the official interval...the dealer said every 100K and the Maintenance link said 90-120K, so I've been using 100K as the baseline.

kaloman

Thanks everyone. I ended up not using anti-seize and everything went well. The old plugs, which had 60k miles on them, came out fine and the new ones screwed right in. Just took my time. One thing that I did to prevent a socket mishap was to electrical tape it to the socket extension. This ensured that the socket would not come off and be left inside of the cylinder.

Hopefully this saved me a few hundred bucks at the dealership.

MJG87

Good job mate, saves money and feels great to work on the car yourself. I started working on mine years ago and have had some great times, made some great friends, and saved a fortune. Can you post a pic of how the old plugs looked after 60k miles?