Spark Plug Removal - How many years?

[KNS]

It dawned on me the other day that I've gone about 10,000 miles or so since my last spark plug change on the '84. The car is driven regularly but does not get a lot of miles put on it in any given year. I realized it's been ten years (!) since the spark plug change.

This seems too long when one hears of plugs seizing in heads after X number of years. When I changed the plugs in 2010 the old ones came out fine and the new ones went in no problem. By the look of the plugs all cylinders seemed healthy at that time. I'm fairly certain I put a tiny bit of anti seize on the threads of the new NGK plugs back then.

So this is my next task. Any precautions other than go slow and patient? I can't believe so much time has passed, seems like a rookie oversight...

[john walker's workshop]

Every 15K service.

[KNS]

Thank you John. I was concerned about the 10 year passage of time and the plugs possibly being seized in the heads after so long.

[Dan Owens]

Originally Posted by KNS

Thank you John. I was concerned about the 10 year passage of time and the plugs possibly being seized in the heads after so long.

Kurt,

If you used anti-seize on them there shouldn't be any issue. I always use it, just in case.

[smadsen]

For newer 911's Porsche says 4 years or 40,000 miles for plugs. Funny, but other makes will recommend 100,000 miles or forever, whichever comes first. I've never had a problem removing a plug that was installed dry & properly torqued in the first place. That said, I like a little dab of anti-seize on the threads before installation.

[john walker's workshop]

Dry for me. YMMV.

[smadsen]

John, I believe this Board is divided, maybe 50/50, over spark plug thread lube vs. dry. What's your rationale? I know if the lube is goobered on it can melt & run off the threads that protrude into the combustion chamber and potentially foul the plug. There's also an argument that a plug with lube could loosen & back out, although I've never seen that happen to a properly torqued plug. I also know the Porsche shop manuals tend to agree with you.

Just curious what you think.

[proporsche]

i`m with John i put them on dry..never had a problem...

Ivan

[manbridge 74]

Always dry.

Recently pulled plugs on a 73T that was last worked on on the 80s. No issues on removal.

[john walker's workshop]

Originally Posted by smadsen

John, I believe this Board is divided, maybe 50/50, over spark plug thread lube vs. dry. What's your rationale? I know if the lube is goobered on it can melt & run off the threads that protrude into the combustion chamber and potentially foul the plug. There's also an argument that a plug with lube could loosen & back out, although I've never seen that happen to a properly torqued plug. I also know the Porsche shop manuals tend to agree with you.

Just curious what you think.

When I worked at the local dealer in the 70s, they insisted dry, so that was that.

[E Sully]

On NGK's website, they specify not to apply anything to the threads.
First, they state the plating on the threads has anti seize properties. Second, they have noted that applying anti seize compound changes the torque needed to install spark plugs. This has a tendency to increase the chance of over tightening and stripping threads.
Using this information, I do not use anything when installing new plugs, but if re installing I will use a small amount, but reduce torque when tightening.

[Biff]

After experiencing an occasional galled plug thread I started to use a "conservative" amount of Nickel Neverseize. The environment for galling threads is present with dissimilar metals, high heat and many heat cycles. Since using it I've never had a stuck plug. Its not a good time repairing plug threads while in car!

[Flat Six]

Originally Posted by E Sully

On NGK's website, they specify not to apply anything to the threads.
First, they state the plating on the threads has anti seize properties. Second, they have noted that applying anti seize compound changes the torque needed to install spark plugs. This has a tendency to increase the chance of over tightening and stripping threads.
Using this information, I do not use anything when installing new plugs, but if re installing I will use a small amount, but reduce torque when tightening.

^^ This; how I've done it for many years

[Ian Comerford]

You can’t actually over-tighten if using a torque wrench, the torque is the torque. It will screw in further if lubed though

[cmcfaul]

using iridium plugs in an 89 Carrera, any reason to change before 20k mi?
No oil burn. About to do the cap and rotor.

Chris

[carreradpt]

Originally Posted by john walker's workshop

Every 15K service.

This is the reason.

But of course you can go longer, but why?