About to change the plugs in my '05 TL (at 82K miles) and though I have changed plugs in many cars back in the day, this is my first time dealing with aluminum heads so I'm a bit nervous about getting the torque right. In all the discussions and the DIY instructions on this forum it is suggested I use anti-seize and torque to 13 ft-lbs. But the NGK site (I'll use the stock NGK plugs) says to not use anti-seize (see http://www.ngksparkplugs.com/pdf/TB-...1antisieze.pdf). So what's the consensus out there? And if I don't use anti-seize, what's the torque spec?

 

Use antisiege or the spark will back out and destroy your heads

 

I didn't use anti seize and torqued it to 16-18 ft/lbs.

I also changed my spark plugs recently with 82k miles on the factory plugs.

 

Not clear to me how anti-seize will keep the plugs from backing out. Loc-tite, sure, but anti-seize?

 

You don't need to... this is taken stright off NGK's site:
NGK spark plugs feature what is known as Trivalent plating. This silver or chrome coloured finish on the threads is designed to provide corrosion resistance against moisture and chemicals. This coating also acts as arelease agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize.

 

Have never once used antiseize on a spark plug. Have never had one backout, and have never had one seize in the head. I say just torque them properly and your good. The factory doesn't put anything on the threads as far as I've seen.

 

Service Manual specs call for A/S and 13ft-lbs. I used A/S on my one SP change (torqued to 13) and have had no issues (63K miles so far).

If you don't use A/S, I'd torque them to 18 - 21 ft-lbs, based on the NGK charts for Al heads. IMO, 16 ft-lbs is too low of a torque value for a non A/S install of NGKs. The link to that chart has been posted before, I'll see if I can find it.

Edit: Actually, it's 18-21.6 ft-lbs (scroll down the page a bit):

http://www.ngksparkplugs.com/tech_su...nml#installing

Overall, I think the key may be to match the appropriate torque to which ever method you choose (A/S or no A/S)...

I'd be interested to hear any supporting documentation for this statement.

 

I'd like to correct myself. I torqued them to 18 and not 16 like I mentioned before. I remember looking at the torque spec ratings for aluminum heads on the NGK website and went with the lowest number in the range which was 18 ft/lbs

 

I'd go with the spark plug manufacturer's recommendation.

 

Thanks to all for the great input. I think nfnsquared hit it right on - 13ft-lbs with anti-seize or 18-21 without. And that makes sense too. Question is whether one wants to go with the service manual or NGK. My first inclination is to go with the service manual, but like others since I've never used anti-seize on a spark plug I'll probably go without.

 

factory don't come with anti-siege since they do have the coating on them. But how many people have had blow spark plugs on their first set of sparks.

http://www.ngksparkplugs.com/pdf/tb-...1antisieze.pdf

Do 13 with anti-siege or higher like everyone suggest for non-anti-siege usage.

 

I don't know if that is true or not. Do you have some proof of this? Hard for me to believe that they come from the factory without A/S when the SM specs call for it.