Going to replace plugs - 86 k miles. 2007, 2.4 l.

Assuming new plugs, and anti-seize, what is a good nominal torque via torque wrench?

What about setting torque by going a certain fraction of turn past contact?

And how about torque for used plugs. This might come up for many reasons.
One idea I have is to go in every 25 k miles, say, and break the plugs loose, then re-torque, to ensure that they don't get welded in.

 

someone will chime in with the correct ft-lbs, but I didnt tighten mine hard at all, I know they can be fragile. 15 ft lbs would be my guess, or a hair tighter than hand tightened

oh and mine came out pretty easy at 55,000 or so miles

 

15 lb ft is right on the money. Which is equal to 20 N.m according to GM.

 

blacky.....

a previous discussion on this forum, many moons ago, revealed spark plug manufacturers use a dry anti seize on the new plugs.....I believe someone stated the info came from the manufacturers websites. But I think many still apply their own compound.

I personally haven't used it ever, and never had a problem....but I don't experience the change of seasons and the possibility of moisture entering the "equation".

Obviously reinstalling used plugs would necessitate the application of compound.

 

I have always done the anti seize and contact then 15 foot lbs on all three 2.2's in the family never had a stuck or broken plug, my brother in-law has had to replace heads twice for broken plugs and I had a look the last time he had the issue turns out he followed the rule of thumb for washered spark plugs, tighten too contact then 1/4 turn tight aand he never used anti seize, live and learn

 

X 2, I believe I was in that discussion long ago..

 

Does GM specify, or discuss, clicker v. beam torque wrench?

 

I've always used a clicker type wrench, beam wrenches are a bit old fashioned and and inaccurate compared to a freshly calibrated clicker wrench.

One thing that seems to have escaped mention, always change the plugs on a cold engine, changing them without letting the engine cool down is courting disaster.

And even though they are brands that HHR's hate. NGK, Bosch, and Denso specifically recommend against using anti-seize in aluminum heads because it can give false torque readings leading to over-tightening.

GM does not recommend its use because the metal plated shells on Delco plugs(Zinc or Nickel plated), will provide the proper torque characteristics when installed dry, no anti-seize compounds needed or advised.

 

Good post!

Right, adding lubricant where not intended implies over torquing.

I use a clicker torque wrench for most purposes. I've never assembled an engine, but don't they use beam style for head bolts? That seems like a similar job, albeit at a much higher torque value. My clicker wouldn't be very accurate down at 15 ft lb, so I'll use this opportunity to get a good clicker in a lower range - and check it with a known accurate beam wrench!

Sooo ... I guess opinions are all over the place on anti-seize. We already know from a previous post that tightening according to a set amount after contact is a hazard, although that would obviate the problem of over-torquing due to extra lubrication.

Maybe the secret is to get a true 15 ft lb without anti-seize, which is a pretty low torque value. It sounds like when plugs come out for the first time, assuming a stone cold engine, there are few problems. That suggests anti-seize is probably not necessary. (Unless GM cheats and uses it at the factory!)

One thing that bugs me about anti-seize, unless I do the work myself, is taking any chance on getting that stuff on the business end of a plug.

 

all I know is that I've been using anti-seize on all kinds of fasteners for too many years to remember and have never had any kinds of torque issues....I really don't think that if a plug is torqued to 14 ft pounds vs. 16 ft/lbs would really make a big difference. but, I do know that removing plugs that had anti-seize applied, especially in an aluminum head, is much easier and lots less chance of doing any thread damage........just my feelings, though...